Since Ford F-150 is now last in V8 HP/tq, why don't they make the 6.8L V10 an option?

Seams like an easy way to get back to #1 it gasoline engines. Does it not fit? Are they too worried about CAFE?

Ford has a whole new line of V8s that will start appearing by early next year that they are looking at to get them back in the unquestioned forefront.

As for the claim they are last in HP and torque, put displacement versus displacement, I'm not convinced that's true.

How does a Ford 5.4 V8 stack up against a GM 5.3, for instance?

I didn't think trucks fell under CAFE, since the Magnun is classified as a truck because of it's 'flat load surface' and thus doesn't count again DCX? I seem to recall some discussion on the matter, but wasn't it shot down?

I didn't think trucks fell under CAFE, since the Magnun is classified as a truck because of it's 'flat load surface' and thus doesn't count again DCX? I seem to recall some discussion on the matter, but wasn't it shot down?

Trucks have separate (and less stringent) CAFE requirements. That's why it pays to get as many vehicles as possible classified as trucks.

As for the claim they are last in HP and torque, put displacement versus displacement, I'm not convinced that's true.

How does a Ford 5.4 V8 stack up against a GM 5.3, for instance?

I think the point is, if you're looking for a competitively powerful 1/2 ton and have the money to spend for the top of the line models, you aren't looking at Ford. The top 300 horse 5.4 doesn't even pull away from the middle of the road GM 5.3.

Will the new F-150 engines come out with the '09 redesign or sooner?

Ford has a whole new line of V8s that will start appearing by early next year that they are looking at to get them back in the unquestioned forefront.

As for the claim they are last in HP and torque, put displacement versus displacement, I'm not convinced that's true.

How does a Ford 5.4 V8 stack up against a GM 5.3, for instance?

5.x motors.....

Ford 5.4 = 300 @ 5000 / 365 @ 3750
GM 5.3 = 315 @ 5200 / 338 @ 4400
Dodge 5.7 = 345 @ 5600 / 375 @ 4400
Toyota 5.7 = 381 @ 5600 / 401 @ 3600

Those numbers can be spun any number of ways (pardon the pun). However, looking solely at useable power, Toyota has the market right now. Ford doesn't do bad compared to either GM or Dodge when you consider that you want power in the low rpm range with a truck (torque peaks below 4k, while it is above 4k for both the GM and Dodge motors).

For the 4.x liter V8s....

Ford 4.6 = 248 @ 4750 / 294 @ 4000
GM 4.8 = 295 @ 5600 rpm / 305 @ 4800
Dodge 4.7 = 235 @4800 / 300 @ 3200
Toyota 4.7 = 271 @ 5400 rpm / 313 @ 3400 rpm

For my truck, I'm taking the Toyota or Dodge motor if I have to use the smaller V8, as both make excellent power low in the rpm range. The Ford is lagging, and the GM motor is too high strung (for a truck).

GM does have the best fuel ecomony (becoming more and more important).

Source: Each car maker's website (Dodge's sucks), and www.fueleconomy.gov.

5.x motors.....

Ford 5.4 = 300 @ 5000 / 365 @ 3750
GM 5.3 = 315 @ 5200 / 338 @ 4400
Dodge 5.7 = 345 @ 5600 / 375 @ 4400
Toyota 5.7 = 381 @ 5600 / 401 @ 3600

Those numbers can be spun any number of ways (pardon the pun). However, looking solely at useable power, Toyota has the market right now. Ford doesn't do bad compared to either GM or Dodge when you consider that you want power in the low rpm range with a truck (torque peaks below 4k, while it is above 4k for both the GM and Dodge motors).

For the 4.x liter V8s....

Ford 4.6 = 248 @ 4750 / 294 @ 4000
GM 4.8 = 295 @ 5600 rpm / 305 @ 4800
Dodge 4.7 = 235 @4800 / 300 @ 3200
Toyota 4.7 = 271 @ 5400 rpm / 313 @ 3400 rpm

For my truck, I'm taking the Toyota or Dodge motor if I have to use the smaller V8, as both make excellent power low in the rpm range. The Ford is lagging, and the GM motor is too high strung (for a truck).

GM does have the best fuel ecomony (becoming more and more important).

Source: Each car maker's website (Dodge's sucks), and www.fueleconomy.gov.

Bob you left out GMs 6.0 V8 that puts out about 360 horses. Also I think many here hope the 6.2 AFM VVT V8 finds its way into the GM pickups pretty soon.

Yes, I was responding to Guy's post....ie....comparing like (or similar) displacements.

That said, the 6.0 makes 375 lb/ft torque @ 4300 rpm. The 5.4 makes 365 lb/ft torque @ 3750.

Bob

Screw it, GM should just go all out and option the 6.2 VVT with 6spd auto from 1500 on up.
Then compare the physical size of the 6.2 to the new 5.7 V8, and show that GM can make more power out of a smaller package.

Yes, I was responding to Guy's post....ie....comparing like (or similar) displacements.

That said, the 6.0 makes 375 lb/ft torque @ 4300 rpm. The 5.4 makes 365 lb/ft torque @ 3750.

Bob

http://img242.imageshack.us/img242/4424/ohoq9.jpg

The F-150 is also the heaviest of the bunch. Now, I don't know how many people get into stoplight races with their 1/2 ton trucks, but it's still good for bragging rights. The general view on the street is that the Ford motor has fallen to the bottom of the pack. Sure it's a torquey motor for its size but when you compare the total package--engine and weight--I could see how it might feel inferior.

Ford has a whole new line of V8s that will start appearing by early next year that they are looking at to get them back in the unquestioned forefront.

As for the claim they are last in HP and torque, put displacement versus displacement, I'm not convinced that's true.

How does a Ford 5.4 V8 stack up against a GM 5.3, for instance?

I guess the Boss V8s will be out soon enough (2009?)

The Lincoln Navigator is a vehicle they should have really looked into adding the 3v V10

The Ford V10 isn't that strong and the gas mileage is in the single digits.

The F-150 is several hundred lbs heavier than most, which certainly hurts all areas of performance.

If you're after stoplight bragging rights, then ok - talk about HP, and forget about how much rpm it takes to get that HP. HP rules the day here. But for trucks, it really is worth nothing but for bragging, and the other guy can brag just as forcefully this their truck makes great torque at xxxx lower rpm.

That said...I'm not trying to dispute your assertion that Ford has fallen to the bottom of the truck engine power pack. In fact, I generally agree.

Final comment....the 4.6/5.4 motors are good truck motors. However, the current trend has been towards bigger/more powerful motors, and 5.4 liters is about as big as the mod motor will get without adding two more cylinders to it (isn't currently available in light trucks anyway). A new engine architechture is needed bad, and soon.

About the V10...it is 6.8L, and is rated at 362 hp @ 4750 rpm and 457 lb/ft torque @ 3250 rpm. Given the low rpm power numbers (to say nothing of its physical size and weight), it is certainly a "truck" motor.

robvas....where do you get your MPG numbers for V-10 equipped trucks?

Bob

Peak numbers are irrelevent. The curve is important. The tq curve on my LS1 looks like a table. I make 350+ from 3000-5700 with a peak of 373. It is over 300 at 2500 rpms.

All trucks sold now are VERY powerful. They have at/near/over 300 HP and even more torque! Most F-150s are for light duty work, hauling electrician's or plumber's toolbox to and from work, or for off-road use to get to job sites through mud.

Why does everyoen feel the need to have the most powerful engine in a truck? It's not a race car! And it's not that owners actually NEED such powerful engines.

If anyone can justify needing a V10 engine, they should go to a heavy duty series F250 or F350, and better yet, get a diesel engine. There should be no need for gasoline V10 in truck applications.

Why does everyoen feel the need to have the most powerful engine in a truck? It's not a race car! And it's not that owners actually NEED such powerful engines.

I don't think anyone is going to dispute that. But the fact remains, when the competition is able to offer more for the money, it's going to be a big selling point. I mean, hey, why not get the most bang for your buck, all other things being about equal?

On a side note, F-150 sales continue to fall. This could be the year the Silverado ends its 30-year #1 sales run.

The Toyota truck is amazing.

The engine is out in the middle of the bay. Easy access from all sides like the good old days. Not shoved up under the cowl like the other guys.

And the best HP

And a 6spd tranny

The Toyota truck is amazing.

The engine is out in the middle of the bay. Easy access from all sides like the good old days. Not shoved up under the cowl like the other guys.

And the best HP

And a 6spd tranny
Yea, alot of other good mechanical parts in there that will give them a hardy image. At this rate it will become the farm truck you can throw around and not worry about breaking anything.

The Toyota truck is amazing.

Nah, the Toyota truck's top powertrain is amazing. What Toyota will find out in this latest attempt is that you can't be good in just one area. The problems I still see are:

1. Milktoast mid-level V8 (4.7) where most of your volume comes from.
2. Ghastly interior.
3. Doesn't stand up to the domestics in terms of value. You can get the 4.8 Silverado for around the same price as a V6 Tundra. No thanks.

if i ever get a job driving up and down gigantic teeter-totters, or drag racing on strips that dead end into canyons, ill get a tundra, until then...ill pass

I think the point is, if you're looking for a competitively powerful 1/2 ton and have the money to spend for the top of the line models, you aren't looking at Ford. The top 300 horse 5.4 doesn't even pull away from the middle of the road GM 5.3.

Will the new F-150 engines come out with the '09 redesign or sooner?

Not sure when it will come out. Personally, I believe it will appear with the redesigned trucks. However, there are some who believe it will come out earlier. I haven't bought into that yet.

As for not looking at Ford, I'd say that's probally not true. Ford has all but owned the pickup truck market for longer than most posters here have been alive.

GM, on the other hand, has been cleaning Ford's clock in the luxury SUV market, despite the fact Navigator created the market. I don't have any numbers in front of me, but I think Tahoe is outselling Ford's big SUV.

Does it not fit? Are they too worried about CAFE?

1. No, I'm betting it doesn't. The 5.4L is a VERY tight fit. Heck, even that 4.2L v6 is crammed under the cowl just a bit...

2. Irrelevant. See #1.

My apologies for destroying a thread that went on for too long...

1. No, I'm betting it doesn't. The 5.4L is a VERY tight fit. Heck, even that 4.2L v6 is crammed under the cowl just a bit...


Instead of betting, please quote the dimensions of both motors (5.4 vs 6.8) - most importantly, the width, as that is where the fit is "tight".

Thanks.
Bob

Instead of betting, please quote the dimensions of both motors (5.4 vs 6.8) - most importantly, the width, as that is where the fit is "tight".

Thanks.
Bob
With accesories being arranged differently, a picture would probably be better.

1. No, I'm betting it doesn't. The 5.4L is a VERY tight fit. Heck, even that 4.2L v6 is crammed under the cowl just a bit...

The 6.8 V10 is no wider that the 5.4 3v and just a bit longer. You can cram a 6.8 V10 under the hood on an SN95 Mustang without to much pain.

Unrelated, but, y'know a 6.8 3v V10 would be pretty cool under the hood of the current mustang and probably weighs in or is lighter than the S/C mill now and could make an easy 500 hp, but enough of the LSD laced coolaid - nobody in Ford has the cojones to do that.

The 6.8 V10 is no wider that the 5.4 3v and just a bit longer. You can cram a 6.8 V10 under the hood on an SN95 Mustang without to much pain.

Unrelated, but, y'know a 6.8 3v V10 would be pretty cool under the hood of the current mustang and probably weighs in or is lighter than the S/C mill now and could make an easy 500 hp, but enough of the LSD laced coolaid - nobody in Ford has the cojones to do that.


The 6.8 3v V10 has 362 horsepower and 457 lbs/ft of torque.

The blown SVT 5.4 has 500 horsepower and 480 lbs/ft of torque.

One can only speculate on the V10's fuel economy in the Mustang, but it IS worse than the blown SVT 5.4 Lightning was. The GT500's rating is 15/21...... the same as my 145 horse, 305 V8, 1978 Chevrolet Monza Spyder was.

From a weight standpoint, I'm guessing there isn't much difference, but packaging is likely far easier (and cheaper) with the V8.

In short, there's currently no logical reason on the planet for Ford to stick a Triton V10 in a Mustang.

In short, there's currently no logical reason on the planet for Ford to stick a Triton V10 in a Mustang.

Yeah, I know, but adhering to logic (http://s22.photobucket.com/albums/b303/bossco/?action=view&current=illogical.jpg) all the time, well just stinks.

I don't know the particulars of the 6.8 V10's tune, but I figure it's along the same line as the regular 5.4 3v in F150, however if it were given a GT style tune, then your talking 443/473, give it a premium fuel tune and that'd jump to 480/487 with an abundance of torque, you could elminate the charge motion plates and pick up a bit more and then to top it off they could use the porting program from here (http://www.fordracingparts.com/parts/part_details.asp?PartKeyField=9447) I think that'd make the 500 hp using pretty much off the shelf stuff. Or maybe darn close (given things like the extra drag from the cylinders and the balance shafts). The 6.8 3v is narrower than the 5.4 4v and probably only about 6 inches longer (if that) and now that I think about it probably lighter (given the weight of the super-charger and the intercooler set-up) and maybe cheaper too (regulatory costs aside).

Ford already did the v10 mustang, I figured people on this board would be hip to that already. http://www.autofieldguide.com/articles/050401.html The article says anywhere a mod V8 goes so will the V10.

Yes, the Boss 351 car, pretty bad arse, it was a one off short deck V10 using one off DOHC 4V heads and displaced 5.8 liters. (essentially a DOHC 4.6 with 2 cylinders tacked on). The V10 mustang makes it on here when people generally discuss the craptacular sound a Viper makes with its V10 and the sound of V10's in general. Then usually the Boss 351 comes up as the killer sounding V10.

--->edit below<---
Man, the V10 is a whopping 3.93 inches (100 millimeters) longer

All trucks sold now are VERY powerful. They have at/near/over 300 HP and even more torque! Most F-150s are for light duty work, hauling electrician's or plumber's toolbox to and from work, or for off-road use to get to job sites through mud.

Why does everyoen feel the need to have the most powerful engine in a truck? It's not a race car! And it's not that owners actually NEED such powerful engines.

If anyone can justify needing a V10 engine, they should go to a heavy duty series F250 or F350, and better yet, get a diesel engine. There should be no need for gasoline V10 in truck applications.

Wisest post yet in this thread. :bow:

I drive trucks. Just put 260 miles on my 250 this weekend in fact - pulling a Mustang on a trailer (with tires and other goodies required for a weekend at a road course). Recently had 48 bales of hay on the back of mine at about 50lbs each. I have a farm, tractors, cars, and such, so I WORK my truck.

I started out pulling a car behind a half-ton truck years ago, and it did "well". Until one day when I had to make an avasive maneuver to avoid an idiot that pulled out in front of me. I had a '72 LTD on a trailer (car was about 4000lbs, trailer about 1200lbs, and the truck was about 5400 lbs tare) that I was taking home to strip the 429/C6/9-inch driveline out of. Despite 2 chain dogs, and a wench, the LTD shifted right on the trailer, and the partially inflated front tire (unknown to me it was going down) managed to drop off the trailer's right edge. We were going down a long incline during this "event". When the car's lower arm hit the trailer, it set off a bounce that started a resonation - it kept getting worse and worse. The car and trailer started "driving" the truck, bouncing it up and down and going side to side simultaneously. Trying to apply brakes only gave the car/trailer more leverage against the truck which made the side-to-side movements worrse, so the only way out of the resonation was to apply the gas.

Well, I managed to save it all, and we can laugh about it now, but it was NOT funny when it happened. THAT event alone convinced me that I need some serious equipment if I am going to haul stuff like that around... and so came the 250SD. Now, I have no trouble dictating where the truck, trailer, and car will go.;) I have both powered my way out of bad traffic situations, and I have also used the mammoth brakes to stay out of incidents. Speaking personally, I would never consider towing a heavy car on a trailer behind a half-ton ever again, simply because I know how much more capable a 3/4 or 1-ton is at doing it. It was not that my F150 was not capable of towing a car - in fact it did a pretty good job overall, it was the unexpected situation that forced me to make radical maneuvers that caused the load shift and resulting chaos, and put me at the limitations of the vehicle. I don't ever plan to be there again. :no:

So back to the topic - I think these new 1/2 ton trucks are all getting out of hand. The manufacturers need to concentrate more on efficiency than total HP available. Likewise, I'd rather see them concentrate on Tq than Hp, because Tq is what makes a truck "work". More Tq, as early as possible in the RPMs, the better.

As adamantly as I promote carmakers to start working on weight savings in cars, I likewise promote truck builders to build "tough". I don't promote adding weight for the sake of adding it, but if you can make a stronger frame by adding more crossmembers - I say put them in. A beefier tranny weighs 30lbs more - no problem. Be concerned with DURABILITY though - not just making the 1/2 ton turn into a 3/4 ton.

To me, "bragging rights" are not something you say on the internet or at a bar... they are the scratches and dings on the truck. Bragging rights are thousands of odometers with 100k, 200K, or even more on them. IMO, if you don't keep a truck long enough to wear it out or beat them up a little, you aren't fully qualified to speak on what makes a good truck good, or a bad one bad. If you are discussing what type of leather seating it has or the plastic on the door panel - you don't need a truck... you need a luxury SUV or a car.

Closing - I'd much rather see a 1/2 ton truck with a 5-cyl diesel than ANY of the V8 or V10s we have been discussing. Better fuel economy, longer operating life expectancy, better torque, and basically more durable (and less weight). I'm to the point I could care less about these HP and Tq ratings that truck builders are throwing at each other. They are all making more than a basic 1/2 ton truck can use at it's designed capability anyways. Does it REALLY matter if one truck can accelerate to 60 pulling a 10,000lb load 1.6 seconds faster than the other?!?! I'd call you a blooming idiot for attempting such accelerations with a load anyways. When pulling a big load safely, you should adjust your acceleration down to keep the engine at max Tq - not max Hp, ease at the shift points so that the tranny does not get "pounded" by discontinuities in torque, and most important - keep the load stable by minimizing the external forces applied to it.

I wish they'd stop or outlaw these goofy commercials where 1/2-ton trucks with 10,000lb boats and loads are pulling out to pass a semi truck going up a mountain, racing through steel gates, or driving towards the edge of a cliff. It promotes impatience, road rage, and it gives people a false sense of invincibility. They can show sh1+ like that, but they can't show a little boy obviously dreaming of a car jump in a Corvette, or a robot contemplating suicide... :confused:

<puts soap box away, gets caffeinated drink, and goes back to work>

Proud,

All valid points, but in the world of marketing and intense competition for your dollar, more is always going to be seen as better. The bigger the better, the more power the better. We might know the score here, but there's a ton of goofballs out there that don't (that thing got a Hemmay?)

The lines have long ago been blurred in regards to 1/2 ton, 3/4 ton, etc. Trucks really can't be thought of with those designations anymore. Now, anyone with some common sense would know not to pull a 5th-wheel with a "1/2 ton" truck, regardless of whether or not it could do it. But I think it gives the macho guys an extra sense of security knowing it can tow 10,000 pounds-plus.

I'm all for advancing fuel economy in pickups, and I think that's happening. I can't wait for a diesel offering in GM's 1500 line. I think it will be a very popular option, especially if it's priced to be worthwhile.

Excellent post. :bow:

When you get to the brass tacks of it, horsepower numbers are irrelevent when talking about regular trucks.

First, it's TORQUE that not only provides the "work" as you mentioned, but it's torque that provides acceleration and "feel" of power.

Second, and just as noteworthy, pickup trucks are governed to just around 100 to 110 mph, regardless of horsepower. Only exception is purpose built trucks like the Ram SRT-10 or the long dead Ford Lightning. Silverado SS is governed to under 110.

The 400+ horse Escalade's party stops at 107 mph. All regular Chevy trucks stop at 100.

Of course, if the price of a new vehicle is but a drop in the bucket of your vast wealth, you can void the warranty of your new vehicle and install an aftermarket chip. But there's probally a good reason why large trucks are governed so low in the 1st place.

First, it's TORQUE that not only provides the "work" as you mentioned, but it's torque that provides acceleration and "feel" of power.
Power is simply torque at speed. Torque is ALWAYS providing the work and the accleration (not sure what is meant by the "feel" of power). Engines produce torque when the explosions in each cylinder push the piston down and twist the crankshaft via a lever (connecting rod). The resulting power number is the torque generated at a given engine speed times that given speed. It is torque acting through the gears and to tires/ground that moves the vehicle forward.

Generally speaking, in an acceleration/speed contest, an engine that makes 300 hp @6000 /400 lbft @ 2500 will get beat by an engine making 400 hp @ 6000 / 300 lbft @ 2500 in equal vehicles if the cars are geared appropriately for the engine. The lower power engine may make more PEAK torque and at a lower RPM, which is good for stepping off the line and for getting a heavy load moving, but it is making much less torque at 6000 rpm than the 400 hp engine.

In a car, you aren't typically trying to get a heavy load moving from rest, so having 660 lbft @ 1600 rpm (like the Duramax) is not really necessary. Or, look at 18 wheelers, which often have ratings on the order of 400-600 hp (at maybe 1900 rpm), with 1200-1650+ lbft of torque (at 1500 rpm). :eek:

In working trucks, this is a big consideration. But in the half ton world (what Bryant would call something other than "real" trucks :p), the trucks are often used primarily as cars anyway, so power numbers are becoming pretty important. It's an interesting line for them to walk.

Note how these cars with 3.5L V6s and ~300 hp / 260-270 lbft are producing LT1 (or quicker) acceleration times. :(

:)

Power is simply torque at speed. Torque is ALWAYS providing the work and the accleration (not sure what is meant by the "feel" of power). Engines produce torque when the explosions in each cylinder push the piston down and twist the crankshaft via a lever (connecting rod). The resulting power number is the torque generated at a given engine speed times that given speed. It is torque acting through the gears and to tires/ground that moves the vehicle forward.

Generally speaking, in an acceleration/speed contest, an engine that makes 300 hp @6000 /400 lbft @ 2500 will get beat by an engine making 400 hp @ 6000 / 300 lbft @ 2500 in equal vehicles if the cars are geared appropriately for the engine. The lower power engine may make more PEAK torque and at a lower RPM, which is good for stepping off the line and for getting a heavy load moving, but it is making much less torque at 6000 rpm than the 400 hp engine.

In a car, you aren't typically trying to get a heavy load moving from rest, so having 660 lbft @ 1600 rpm (like the Duramax) is not really necessary. Or, look at 18 wheelers, which often have ratings on the order of 400-600 hp (at maybe 1900 rpm), with 1200-1650+ lbft of torque (at 1500 rpm). :eek:

In working trucks, this is a big consideration. But in the half ton world (what Bryant would call something other than "real" trucks :p), the trucks are often used primarily as cars anyway, so power numbers are becoming pretty important. It's an interesting line for them to walk.

Note how these cars with 3.5L V6s and ~300 hp / 260-270 lbft are producing LT1 (or quicker) acceleration times. :(

:)

But as you and I both know, in the real world, engines do not all exhibit similar Tq/Hp curves, AND most of the time these same engines do NOT demonstrate the linear relationship governed by their equation P=T/dt.
In fact, Ford's old 5.0 flies all in the face of that linear relationship, belting out 300lb-ft of torque at 2100 rpm only to drop-off to about 190ft-lb at 4000 rpm, while hp is at a lowly 170 at 2100rpm and grows up to 225 at 3800 rpm.
These two curves cross each other at radical angles between the vectors, which indicates a far-from-linear relationship - yet, the 5.0 has been doing it since 1968. :cool:

Just this weekend, me in my 1991 5.0 with 225hp/300tq was able to stay with and handle Cobras with 4.6L running 320hp/317tq . Likewise, I was bowled-over by the Toyota Matrix my instructor brought to play with... he was able to stay within 4-6 car lengths of me and the Cobras on the back stretch where we reach 100-115mph, and he was right on us in the turns. I have no idea what the little engine was in that Matrix, but it was repeatedly taching over 7000rpm. We also had major competition from some MiniCoopers with turbos. I could not pull more than 2 or 3 cars away in the straights, and they were on rails in the corners. TORQUE was my salvation this weekend.:bow:

I'm not saying Hp is negligible, but Hp is FAR more important when trying to maintain high speeds or climb a long uphill grade at speed. Hp actually IS the limiting factor on top speed runs like Bonneville is known for. But for everyday driving and the occasional leapfrog jump at a traffic light, I'll take a sackfull of Tq pellets over a truckload of Hp anyday.:thumb:

But as you and I both know, in the real world, engines do not all exhibit similar Tq/Hp curves, AND most of the time these same engines do NOT demonstrate the linear relationship governed by their equation P=T/dt.
In fact, Ford's old 5.0 flies all in the face of that linear relationship, belting out 300lb-ft of torque at 2100 rpm only to drop-off to about 190ft-lb at 4000 rpm, while hp is at a lowly 170 at 2100rpm and grows up to 225 at 3800 rpm.
These two curves cross each other at radical angles between the vectors, which indicates a far-from-linear relationship - yet, the 5.0 has been doing it since 1968. :cool:

Just this weekend, me in my 1991 5.0 with 225hp/300tq was able to stay with and handle Cobras with 4.6L running 320hp/317tq . Likewise, I was bowled-over by the Toyota Matrix my instructor brought to play with... he was able to stay within 4-6 car lengths of me and the Cobras on the back stretch where we reach 100-115mph, and he was right on us in the turns. I have no idea what the little engine was in that Matrix, but it was repeatedly taching over 7000rpm. We also had major competition from some MiniCoopers with turbos. I could not pull more than 2 or 3 cars away in the straights, and they were on rails in the corners. TORQUE was my salvation this weekend.:bow:

I'm not saying Hp is negligible, but Hp is FAR more important when trying to maintain high speeds or climb a long uphill grade at speed. Hp actually IS the limiting factor on top speed runs like Bonneville is known for. But for everyday driving and the occasional leapfrog jump at a traffic light, I'll take a sackfull of Tq pellets over a truckload of Hp anyday.:thumb:

Matrix = 1.8 DOHC VVT-li 180 hp... with some TRD mods from a roll they are very decent, much like the Corolla XRS. Most people won't even take a second look at these lighter 4 cyl. cars until they cross one in a road race....

The new 180 hp turbo Mini Cooper is sick. The CooperWorks edition will probably have around 230-240 hp in a 2300 lb go cart, and yes they handle like they are on rails.

My SVT has embarrassed friends in F-bods trying to keep up in twisty roads... they are just too light and nimble. I love my Fbod, but it's no match for my SVT and much less for my Merkur in the twisties...

Just this weekend, me in my 1991 5.0 with 225hp/300tq was able to stay with and handle Cobras with 4.6L running 320hp/317tq.

I don't even begin to doubt you. However, you're talking about about going around a road course. In a contest of acceleration or top speed, and assuming equal weight and proper gearing, the 320/317 car would (and does) absolutely destroy a 225/300 car.

Likewise, I was bowled-over by the Toyota Matrix my instructor brought to play with... he was able to stay within 4-6 car lengths of me and the Cobras on the back stretch where we reach 100-115mph, and he was right on us in the turns. I have no idea what the little engine was in that Matrix, but it was repeatedly taching over 7000rpm.
Which means it made relatively low amounts of torque, and thus had to spin to a higher rpm to make good power.

I'm not saying Hp is negligible, but Hp is FAR more important when trying to maintain high speeds or climb a long uphill grade at speed. Hp actually IS the limiting factor on top speed runs like Bonneville is known for. But for everyday driving and the occasional leapfrog jump at a traffic light, I'll take a sackfull of Tq pellets over a truckload of Hp anyday.:thumb:

As much as I try, I just can't agree with this statement (and I'm going to sound like I'm contridicting my original post). HP & Tq are interchangeable - one is a mathematical derivative of the other. They are inseperable, and one is no more important than the other.

What is important, is matching the powerband (or 'torqueband', if you prefer) and gearing of the vehicle with the intended use of said vehicle.

But there's probally a good reason why large trucks are governed so low in the 1st place.

Probably tires, I'd imagine you can't jack the pressure up high enough to sustain the loads imposed by going really fast for a good amount of time. Well that is with conventional tire sizes and the typical tire fitments.

Torque is good. Torque at high rpm is better.

Probably tires, I'd imagine you can't jack the pressure up high enough to sustain the loads imposed by going really fast for a good amount of time. Well that is with conventional tire sizes and the typical tire fitments.

Most probalby, it's just tires.

But also, what truck on earth needs to go more than 80-90 mph? It's a lot of mass moving at high velocity.

Reminds me of the time when I was driving 120 km/h (about 75 mph) and a semi with a load passed me like I was standing still. My estimate is that his speed reached at least 140 km/h (90mph). I'm sure it'll get him to his destination point faster (and perhaps even save his job), but can anyone imagine such a heap of metal losing control? How much damage it could cause?

I know this sounds sort of "think of the children" mentality, or old-fashioned. But trucks should be used only for what they're designed - hauling load. At legal speed limits, or close enough.

Bob, I love your posts... you are a knowledgeable guy and you think before you write - always. I see it. :bow:

I don't even begin to doubt you. However, you're talking about about going around a road course. In a contest of acceleration or top speed, and assuming equal weight and proper gearing, the 320/317 car would (and does) absolutely destroy a 225/300 car.
Thanks... Got video!:thumb:
I have had so many people call BS when you tell them that a BMW 318 with a stock drivetrain was able to pass and drive away from C5s, Cobras, and Z28s. Likewise, a bone stock 1991 5.0, 5spd, 3.08:1 is able to pass and leave a 2006 Mustang GT, manual, 3.55:1 . I started taping my sessions 2 years ago. Made believers of those in the office and my car buddies who are too chicken-sh1+ to actually come to the track!
Bottom line is ANYTHING can and typically does happen at road course events. So much depends on driver's skill. But then there's the brakes, tires, conditions, type of track, weather, fuels, etc - you know the routine. Fact is - I've seen and done it. As thrilling as it might seem for me to pass a new $40k sports car in my 16 y/o Musturd, I also eat humble pie and let the guy in the MiniCooper go by me when he is faster - and that also happened this weekend.
Props go where they go.:bow:


Which means it made relatively low amounts of torque, and thus had to spin to a higher rpm to make good power.
I'm sure the little engine was lower on Tq than my 5.0 - no doubt. BUT, he did have a 6-spd. I think he has 14" rims, and I know they were low-profile performance tires. He did have Carbon-Tech pads (stock rotors). A 6-spd and smaller rims both serve to multiply (or at least maximize) the use of engine torque, and he was able go much deeper into the turn than me before braking, as he had 4-wheel discs and race pads where I had 2 disc/2 drum and street pads - he gained a lot of time right there.
So, you are right - he did keep the rpm high to use the Hp. But if latinspice-94T/A's posted numbers are correct, Chris was making @ 180hp at peak rpm in his Matrix, where I was also at about 170-180Hp when my rpms were down in the 2700-3000 range. So as we pulled out onto a back stretch, we both were putting down about the same actual Hp. It was my TORQUE that allowed me to pull away from him going down the stretch - simply holding my foot down in 4th as he went through 3rd, 4th, and even into 5th. So in this instance, we had roughly equal Hp but one car had gobs more Tq... and the Tq made the difference.

I actually rode in his car for 6 hot laps with him driving it. I couldn't see the instrumentation - it is buried deep into chrome-rimmed pods and the passenger simply can not see the gages. But I asked him what kind of RPM he was turning. He said well over 7000, close to 8. He tries to keep it over 5000 at all times on the track. Car had 40k miles on it. I am man enough to admit that I was impressed with this car.


As much as I try, I just can't agree with this statement (and I'm going to sound like I'm contridicting my original post). HP & Tq are interchangeable - one is a mathematical derivative of the other. They are inseperable, and one is no more important than the other.
I respectfully disagree a tiny bit - especially when dealing with engines.
You can slap a turbo on a 4-cyl and go to the moon for Hp, but you will be hurting to put Tq into it. F1 cars epitomise this... they are extremely low on Tq and often stall when dropped in the pits, they can take forever to get up to speed, but once they are finally in the powerband - they are GONE. On the opposite extreme, if your sole objective is to move a mountain, you need a crank with a longer throw which will provide you with more displacement and a mountain of Tq, but will not rev as quickly as a tiny I4. Why do people bore and stroke 460s and 455s out to 700+ cubes in top-fuel? TORQUE!!!
NASCAR is unique in that they need the best of both worlds... fast starts but high-revs and top-end speeds. They have consolidated to engines of around 358 ci which provide low rpm torque, and have pursued valvetrain technology that allows them to exceed 9000 rpm to get the Hp they need at the top end.
All 3 engine examples can easily produce 800hp, but their applications dictate their torque requirements and the architecture of the engine required to yield such figures.

IMO, torque is what causes acceleration of mass - PERIOD. (we all know F=mA, and torque is simply a force applied at a distance(length of the lever arm)).
I have been in many a stoplight encounter where the brutal torque of my well-tuned 5.0 has put me out in front of other cars with more HP, and typically I stay there until we reach speeds where I am limited by gearing and RPM and the other guy has finally reached his power zone and can benefit from it.
To me, "torque gets you moving, power pushes you on." Blending the lines of those two is some of the "art" of racing.


What is important, is matching the powerband (or 'torqueband', if you prefer) and gearing of the vehicle with the intended use of said vehicle.
ABSOLUTELY! :bow:
On a 2.4-mile road course with 14 turns, many of which are more than 90*, and tangents that are often 100 - 300 yards long, accelerating from 30-40 mph up to 60mph and braking back down to 30 again is critical. All the big-engined cars have an advantage on the 4 long straights. Likewise, regardless of their power, all light cars (typically meaning 4-cylinder compacts) have an advantage in the tight sections with lots of corners. Many guys readily concede torque for weight savings in this field, but given todays turbos and blowers, you can pretty much equalize the Hp between a 4-cyl and a V8... but not the torque. The end result is a MiniCooper or Miata that is within tenths per lap of Corvettes, Cobras, and Mustangs - it gets clobbered on the stretches but gains back time in the curves.
(Just for giggles, here's a link to the track website... Carolina Motorsports Park (http://www.carolinamotorsportspark.com/))
And here's an "arial" of the track...
http://www.carolinamotorsportspark.com/images/track.gif

PS - I kept re-reading your first statement and I think you did actually contradict yourself a bit there.
In a top-speed run - we both agree that Hp is what it takes. Agreed... and done.
In a pure acceleration run (like a 1/4 mile drag), if all weights, gearing, reaction times, aerodynamics, etc are all equal, the ENGINE (as opposed to the car) with the most area under BOTH curves will win. It's not necessarily the one with the most Tq or Hp, but the one that has the most of both to offer because that kind of race is so time-dependent.
So in the end, I don't think we are really so far away from each others' POV.:shrug:

How did I end up here from talking about trucks?!?!

OMG... I need caffeine! :shock:

Reminds me of the time when I was driving 120 km/h (about 75 mph) and a semi with a load passed me like I was standing still. My estimate is that his speed reached at least 140 km/h (90mph). I'm sure it'll get him to his destination point faster (and perhaps even save his job), but can anyone imagine such a heap of metal losing control? How much damage it could cause?


lol, stay outta SE Va in the area of Richmond to Hampton, I find it kinda scary too when that much metal is flying down a highway. A few days ago I went to pick up my sister-in-law, after picking her up we were merging onto 64 and traffic was kinda heavy. Anyways, when I merge (regardless of a yield sign or not) I always check out the traffic, pick my spot and accelerate to speed where I can merge without interupting the flow of traffic then slow down to whatever the speed traffic is moving at. This night though a truck driver had a case of occularectinitus when I went for my spot in traffic, I accelerated and topped out 3rd gear and was well into the rumble strips before I could merge with traffic in the right lane, cause this guy didn't want me in front of him. Generally in my car 3rd gear is in the 90+ range when you have to shift. Seemed kinda crazy to me to be flinging that much metal around in the right lane at probably 80+ mph just keep me from merging. :shrug:

How did I end up here from talking about trucks?!?!

OMG... I need caffeine! :shock:

Can only ramble on about a situation that will probably not improve itself substantially for the next 2 or 3 years.

Proud....no disagreement with the majority of your post. In fact, I can tell you the story of how a well-seasoned driver in an A4 V6 99 Mustang (rental) was lapping Summit Point faster than I was in my mildly modified 99 M6 T/A. Obviously my car was far more capable of his - but the "driver mod" was in full force!

Torque is work - of course it "causes" acceleration. However, 300 lb/ft of torque at 5000 rpm will accelerate a car quicker than 300 lb/ft of torque at 3000 rpm, everything else being equal. I would add that a car that makes its power down low (torque peak at lower rpm) is certainly easier to drive fast than a car that is "high strung". But in the end, the car with more HP (torque * rpm) will go quicker, everything else being equal.

HP/Tq curve....in a very real sense, this is what matters most. The car making the most average power (or torque * rpm, if that is the preference) in each gear will accelerate quickest. If you have a very 'peaky' motor, that drops well out of its powerband on a shift, then it will suffer. Similarly, if you have one that it pretty much doesn't matter where you shift it - its going to make power, then you'll go relatively fast (see "easier to drive" above).

My apparent contridiction...what I was trying to point out is that the 4.6 motor makes its power down low - evidenced by the lower rpm at which its peak torque occurs. IMO, trucks spend much more time at lower rpm, thus the benefit of more power at low rpm.

To illustrate this....lets look at the Ford 5.4 and GM 5.3 numbers I posted earlier. The 5.4 is making 365 lb/ft at 3750 rpm, and thus is making 261 HP at the same rpm. The GM 5.3 makes its peak torque of 338 at 4400 rpm, but lets assume it is also making the same torque at 3750 rpm (and by definition, it has to be making less, but it is a convenient number to use for comparison). Given this assumption then the GM 5.3 is making 241 HP at the same rpm (and actually somewhat less - would have to see the actual torqe at 3750 to be exact). The 5.4 is thus making more power at a lower rpm, making it more useable in a truck, from my perspective.

Finally...and once again....torque and HP are inseperable. HP is a much easier number to work with though. For example...tell me a car makes its peak HP at 6000 rpm, and I can give you a very good idea of where to shift it. Tell me the same car makes its peak torque at 3500 rpm, and I wouldn't have a clue.

Bob

However, 300 lb/ft of torque at 5000 rpm will accelerate a car quicker than 300 lb/ft of torque at 3000 rpm, everything else being equal.

For me, it's all good but this part.

I maintain that the car with 300Tq at 3000 will achieve it's max Tq delivery SOONER than the car that needs to rev to 5000. While the 5000 car is reaching that peak Tq level, the 3000 car will have already been applying max Tq and thereby applying max force to the tires and pavement, and that car will be checking out. (unless you launch the cars at their respective peak Tq revs, which will just result in tire smoke or broken parts... :D )

Speaking from the gut, the 3000 car will jump out front by a decent margin early, then as it winds-out (and Tq starts falling) the 5000 car will catch back up and pass ahead of it as they near top speeds (of the engines and cars) respectively.

Remember... acceleration is not linear - much like a Tq or Hp curve is not. They are typically exponential (parabolas). It will go from 0 to some BIG number very fast (within the first second), then it will slowly ramp back down to zero as the car reaches it's terminal velocity. The 3000 car will have a bigger initial number (and hence initial speed) - I guarantee that - and it will also start going back down faster too. The 5000 car will have a smaller initial number (and hence initial speed) yet it will not drop off as quickly as the other car due to the 5000rpm capability, so it will slowly wind-in the other car.

As you said before, the gearing, tire dia, aerodynamics, etc has EVERYTHING to do with which car ends up with better top-end speed, and initial 0-30, 0-60, 0-100 times etc. But if "all things were equal", I'd bet on the 3000 car to lead for the first bit, and bet on the 5000 car to have the better top end.

You know neither of us can "prove" anything when we are speculating on theoretical equalities such as this. It would be neat if we could!
Maybe we need to send this in to "MythBusters" and see what they come up with!:thumb:

G-man :cool:

Maybe if they only have one gear. The big advantage of torque at higher rpm, especially in an acceleration contest, is that you do not have to upshift as early and lose your torque multiplication.

I bookmarked this link a long time ago because it is pretty handy every now and again :)
http://vettenet.org/torquehp.html

For me, it's all good but this part.

I maintain that the car with 300Tq at 3000 will achieve it's max Tq delivery SOONER than the car that needs to rev to 5000. While the 5000 car is reaching that peak Tq level, the 3000 car will have already been applying max Tq and thereby applying max force to the tires and pavement, and that car will be checking out. (unless you launch the cars at their respective peak Tq revs, which will just result in tire smoke or broken parts... :D )

Unfortunately, that is not how it works. To really get into it, torque at the engine doesn't matter - torque at the wheels does (and is thus affected by a number of things - such as gearing, tire size, etc). Additionally, if that were
the case, then why not make an engine that made 300 lb/ft of torque at 100 rpm, gear it accordingly, and call it a day? Wouldn't that make sense? Less rpm would have a whole host of benefits?

Additionally, the car that made that power down at 3000 rpm would only accelerate faster if you made the other car start at the same low rpm. However, if optimized for the engine, the car with more power (torque * rpm) is going to accelerate faster.

The problem is torque, by itself, is fairly useless in cars. Torque * rpm is much more useful. I'm not making this up - honest! Do a google of Torque vs RPM sometime. :)

Speaking from the gut, the 3000 car will jump out front by a decent margin early, then as it winds-out (and Tq starts falling) the 5000 car will catch back up and pass ahead of it as they near top speeds (of the engines and cars) respectively.

Yes - if you make both cars start their run at an rpm that is lower than 3000 rpm.

Remember... acceleration is not linear - much like a Tq or Hp curve is not. They are typically exponential (parabolas). It will go from 0 to some BIG number very fast (within the first second), then it will slowly ramp back down to zero as the car reaches it's terminal velocity. The 3000 car will have a bigger initial number (and hence initial speed) - I guarantee that - and it will also start going back down faster too. The 5000 car will have a smaller initial number (and hence initial speed) yet it will not drop off as quickly as the other car due to the 5000rpm capability, so it will slowly wind-in the other car.

Once again, only if they are forced to both start at some pre-determined low rpm.

As you said before, the gearing, tire dia, aerodynamics, etc has EVERYTHING to do with which car ends up with better top-end speed, and initial 0-30, 0-60, 0-100 times etc. But if "all things were equal", I'd bet on the 3000 car to lead for the first bit, and bet on the 5000 car to have the better top end.

Once again....ah, nevermind. I've said it enough. :)

You know neither of us can "prove" anything when we are speculating on theoretical equalities such as this. It would be neat if we could!
Maybe we need to send this in to "MythBusters" and see what they come up with!:thumb:

G-man :cool:

LOL. When I get home and get the time, I'll link some very interesting Tq vs HP information. it really isn't speculation - it is proven physics....but I'm sure not smart enough to recite it without the reference right beside me. :D

Bob

Maybe if they only have one gear. The big advantage of torque at higher rpm, especially in an acceleration contest, is that you do not have to upshift as early and lose your torque multiplication.

I bookmarked this link a long time ago because it is pretty handy every now and again :)
http://vettenet.org/torquehp.html

Oops....should have read more before I posted - that's one of the links! There is more - much more, for anybody looking for it.

Bob

Torque is work - of course it "causes" acceleration. However, 300 lb/ft of torque at 5000 rpm will accelerate a car quicker than 300 lb/ft of torque at 3000 rpm, everything else being equal. I would add that a car that makes its power down low (torque peak at lower rpm) is certainly easier to drive fast than a car that is "high strung". But in the end, the car with more HP (torque * rpm) will go quicker, everything else being equal.Not sure how to read this. At the instant that both cars are making 300 lb ft, they will accelerate at the same rate (with same gearing, weight, traction, etc.). In other words, the car that is making 300 lb ft at 3000 rpm will accelerate as hard at 3000 rpm as the other car accelerates at 5000 rpm. 300 lb ft = 300 lb ft. Simple as that. As you said, torque is what is accelerates the car. F=ma. F comes from the torque working through the radius of the wheel/tire, m comes from the car, and there's your a. :) My apparent contridiction...what I was trying to point out is that the 4.6 motor makes its power down low - evidenced by the lower rpm at which its peak torque occurs. IMO, trucks spend much more time at lower rpm, thus the benefit of more power at low rpm. This is what I was talking about earlier. Of course, these days with trucks being used as cars, and not so much for getting heavy loads moving, this is probably becoming less significant. And all of this discussion is leaving out the magical effects of the torque converter (which are in 98% of pickups). A looser converter can be used to provide torque multiplication and get the engine up toward its torque peak. To illustrate this....lets look at the Ford 5.4 and GM 5.3 numbers I posted earlier. The 5.4 is making 365 lb/ft at 3750 rpm, and thus is making 261 HP at the same rpm. The GM 5.3 makes its peak torque of 338 at 4400 rpm, but lets assume it is also making the same torque at 3750 rpm (and by definition, it has to be making less, but it is a convenient number to use for comparison). Given this assumption then the GM 5.3 is making 241 HP at the same rpm (and actually somewhat less - would have to see the actual torqe at 3750 to be exact). The 5.4 is thus making more power at a lower rpm, making it more useable in a truck, from my perspective. That's right, in the traditional "trucks need low rpm grunt" world. Those numbers are, of course, full throttle numbers, by the way. So the Ford will have an advantage (maybe not, depending on torque converter matching with the engine torque curves) right off the line, but eventually its power/torque output falls behind the Chevy. FWIW, I don't recall a magazine test in which a 5.4L F150 outaccelerated a 5.3L Silverado. BUT, hook a 7000 lb trailer to each one, and the Ford might pull it off. The added mass of the trailer means the accleration will be slower, so the engines will have more time to be working at the lower reaches of the tach before they make it to those 4000-5000 rpm numbers. The extra grunt of the Ford in those lower reaches might pay off there. As I was saying earlier, having a lot of torque output at really low rpm is ideal for getting big mass moving (which is why 18 wheelers use the engines they use). :)Finally...and once again....torque and HP are inseperable. HP is a much easier number to work with though. For example...tell me a car makes its peak HP at 6000 rpm, and I can give you a very good idea of where to shift it. Tell me the same car makes its peak torque at 3500 rpm, and I wouldn't have a clue.

BobAs you mentioned earlier, it is all about the curve; peak numbers are used for marketing purposes to give an indication of what the engine can do. I think the fact that the ratings are typically given as a single torque number and a single power number has confused people about what they really are.

It would be really cool if it became common to show a full load torque curve for all engines instead of just a peak power and torque number. :cool:

Pro Drag racers used to make as much HorsePower as possible and gear accordingly.
The engine at 5,000rpm is doing the work faster, nearly twice as fast, or in less time per revolution, making it easier to move, and has to accelerate faster..."all else being equal"...

Not sure how to read this. At the instant that both cars are making 300 lb ft, they will accelerate at the same rate (with same gearing, weight, traction, etc.). In other words, the car that is making 300 lb ft at 3000 rpm will accelerate as hard at 3000 rpm as the other car accelerates at 5000 rpm. 300 lb ft = 300 lb ft. Simple as that.

Uncle. Have a great day. :)

Bob

Additionally, the car that made that power down at 3000 rpm would only accelerate faster if you made the other car start at the same low rpm. However, if optimized for the engine, the car with more power (torque * rpm) is going to accelerate faster.

I agree. We said the same thing.
In the real world, don't most cars start from a stoplight at idle? @1000rpms or less?
In case they don't, I put this little disclaimer in my post to cover that concept...
I maintain that the car with 300Tq at 3000 will achieve it's max Tq delivery SOONER than the car that needs to rev to 5000. While the 5000 car is reaching that peak Tq level, the 3000 car will have already been applying max Tq and thereby applying max force to the tires and pavement, and that car will be checking out. (unless you launch the cars at their respective peak Tq revs, which will just result in tire smoke or broken parts... )

Yeah, I've googled and yahooed before as well... and I have several bookmarks too.
http://www.modernracer.com/tips/torquevspower.html
"For Mr Average, torque is therefore more important than horsepower, unless you spend your life racing around at high revs. "
http://www.carcraft.com/techarticles/horsepower_vs_torque/
"Engines don’t make horsepower; they convert fuel into torque. Torque is the twisting force imparted to the crank flange and then transmitted to the transmission and the rest of the drivetrain. To some degree torque is the grunt that gets things moving, and horsepower is the force that keeps things moving."


While getting my BSME, I spent 6 months studying automotive powerplants at UNC-Charlotte under Dr. Jerry Hill, an engine designer for Pratt-Whitney. He was on the team that developed the engines for the F14 Tomcats and F-15 Strike Eagles. I triple-minored in Math, Physics, and Computer Science during that first degree too - a result of changing my major from Physics late in my 3rd year (doh!)
I've personally built about 20-24 engines just for my cars alone since 1984, and I've raced everything from 1/8 mile brackets to autocross to full roadcourses. I've picked-up a few things over the years, and I've studied text books... and greasy fingernails... both.:D

I know you are a smart guy. I don't know your precise educational background, but I know you have your title from a few years back too... I've watched you in the rags and mags... I know you can cut a light, and I know you can gear a car to maximize it's output - you pioneered mod-motor performance for many folks a few years ago, and that was no small feat.:bow:

So tell you what... Let's come back to this another time.:thumb:
We've hijacked this thread bad enough already.
Whaddayasay we agree to disagree, and write about something else for a while - more truck related... to this thread?:thumb:

To the thread - in MY truck, I'll take a boat-load of Tq pellets over a sack-full of Hp any day. I have my reasons, but that's what I want in MY truck... and in fact I have just that... @580ft-lbs and about 320hp. :cool:

Uncle. Have a great day. :)

Bob

NO NO NO!!!
You can't do this!!!
I was writing when you made this post!!!


AAARRRRGGGGGHHHHHHHHH!!!!!
:lol:

Seriously - I don't think we are really so far apart in basic theory, just in application. It's a thin line and we are not the only ones wavering across it.

:bow: to you.

Ok.

A couple of things....I launch way, way, way above peak torque at the drag strip. :)

Launching any manual @ 1000 rpm isn't a lot of fun, and most automatics will 'flash' significantly higher than that too.

To put torque to use, you have to do it over time. This is where we get into rpm and thus horsepower.

Car Craft is wrong. Plain and simple. :)

Bob

To the thread - in MY truck, I'll take a boat-load of Tq pellets over a sack-full of Hp any day. I have my reasons, but that's what I want in MY truck... and in fact I have just that... @580ft-lbs and about 320hp. :cool:

Nice, what sorta mill is it (if you don't mind me asking) I keep on trying to get my pops to build a 400 using the 170 E-TEC heads from Edelbrock with a nice custom hydraulic roller to take advantage of the cylinder heads at a relatively low rev range.

But in the half ton world (what Bryant would call something other than "real" trucks :p), the trucks are often used primarily as cars anyway, so power numbers are becoming pretty important. It's an interesting line for them to walk.


Yep - on a unloaded 0-60 run with short rear-end gears (like the 3.73s and 4.10s now becoming common), horsepower starts getting damn interesting - and of course horsepower is definitely a factor at highway speeds (assuming that the transmission ratios are well-matched to the power curve and road speed). And although I don't think it's possible to have too much horsepower in a truck (especially when trying to merge onto a busy expressway from a too-short entrance ramp when towing five tons or so), I do start to get nervous when I see people driving their half-ton trucks like they've seen in the commercials. It's a bad feeling seeing someone yanking a big boat down the highway at 75-80 MPH with their new Hemi Ram and knowing damn well that if they get cut-off by another idiot, something bad is likely to happen.

Originall posted by Eric Bryant:
I do start to get nervous when I see people driving their half-ton trucks like they've seen in the commercials. It's a bad feeling seeing someone yanking a big boat down the highway at 75-80 MPH with their new Hemi Ram and knowing damn well that if they get cut-off by another idiot, something bad is likely to happen.Me too!..I see guys using powerful "1/2" ton trucks hauling loads that a "Full" ton Dually, at the least, should be used...tailgates way lower than the front bumper, tire sidewalls bulging from the weight, and they're trying to run 75mph...like they're trying to prove something.:shrug:
Especially diesels, I see them all the time, hauling Huge Cabin Cruisers around the upper lakes here.
I've personally hauled just over 2 tons of sand in my Silverado 3/4 ton, 2WD, truck bed...talk about a white knucle affair, the front was so light it wondered all over the lane, and I only went 40mph for about 3 miles. But it does show how strong these p/u trucks are.

I've personally hauled just over 2 tons of sand in my Silverado 3/4 ton, 2WD, truck bed...talk about a white knucle affair, the front was so light it wondered all over the lane, and I only went 40mph for about 3 miles. But it does show how strong these p/u trucks are.

You need more tire pressure, then - it shouldn't start getting "interesting" until you get over three tons in the bed. You're right about how strong a modern truck is, however - quite honestly, I've never seen anything but tires fail from overloading. Poor maintenance, on the other hand...

Oh, the hypocrisy - bitch about unsafe truck driving in one post, brag about violating GVWRs in the next. :eek:

Alright, here's my 2 cents.

Engines produce torque, they don't produce horsepower. Different levels of torque are produced at different RPMs.

Horsepower is a meaningful translation of torque, dictating what work the engine actually does.

One of the best examples to understand this relationship is a waterwheel. Take two waterwheels. One has "buckets" that of capacity of 5 gallons. Another has "buckets" of capacity of 7 gallons.

Since horsepower is work done by the engine, you can take the two wheels and spin them at the same RPM, let's say 100 RPMs. The 5 gallon wheel will do 5 x 100 = 500 gallons per minute per bucket. The 7 gallon wheel will do 700 gallons per minute per bucket. Now take the 5 gallon wheel and spin it at 140 RPMs. It will now do the same 700 gallons per minute per bucket as the other wheel. If you spin it even higher, it will surpass the 7 gallon wheel.

This is an explanation of torque in relation to horsepower. Horsepower is the total work done by the engine, much like gallons per minute per bucket.

In real engines, of course, the capacity of the buckets vary with RPM (as does torque - it varies with RPM), and to figure out horespower over the entire powerband of the engine is trickier. The bottom line - work done at the end of the day is what matters.

So yes, torque wins races, but more specifically, it's torque at given RPMs that wins races. Which, in turn, translates to horsepower.

And as Bob pointed out, we're talking about torque at the wheels. And vehicle mass.

So yes, torque wins races, but more specifically, it's torque at given RPMs that wins races. Which, in turn, translates to horsepower.


Never before on the Internet have I observed so many people making this observation so correctly. It's quite refreshing!

People in the auto news forum are just ahead of the curve. ;)

I think this thread by far is the most intresting (and refreshingly expertly) discussion I've seen on any thread on any site in a very long time.

Although we've gone seriously off subject, this is one of those threads you just sit back and read. :)

Nice, what sorta mill is it (if you don't mind me asking) I keep on trying to get my pops to build a 400 using the 170 E-TEC heads from Edelbrock with a nice custom hydraulic roller to take advantage of the cylinder heads at a relatively low rev range.
Sorry to dissapoint, but it's not a gasser, it's a diesel.
Did the 460/C6/4.10 thing in a '75 F-150 Trailer Special.
Pulled like a dozer, and had similar mileage too. 7-8mpg full or empty, :(

Now running a 7.3 PowerStroke... Stock with "a little help".:cool:
20-21mpg empty, never worse than 17mpg loaded to the gills.
3.55:1 rear, 4x4 Off-Road package, towing pkg, extra cooling, etc
Power captains chairs, cloth, CD, power everything.
http://www.yadtel.net/~gcreed1/pics/96A.jpg

To the theme of this thread, I bought my truck to WORK. I pull horses, cars, boats, tractors, hay, and anything else I need to to run a farm and enjoy my hobbys. I frequently have 1000-2000lbs in the bed of the truck, and the only difference you notice is that the ride is smoother with weight in the bed - otherwise the diesel never knows you have anything in there.
I have to put 5000lbs behind it to really start noticing there's a load via the accelerator.
In the image above, I bought a King Cobra and met a guy in Delaware to pick it up. With the KC on the trailer, and a spare engine and transmission in the bed of the truck, I was able to come down US-81 through Virginia towards NC running 75-80mph in overdrive (which is really a no-no) with cruise-control on, and the truck never shifted out of O.D. - it was incredible. I have hundreds of stories like this now, and all it has done is made a believer out of me - diesels are the sh1+ when it comes to work trucks... period.

This is why I am so "uninterested" in these new gas engines with "381hp" in a 1/2-ton. I think marketing is pushing these truck designers and engineers into a bad situation - basically they are going the wrong way IMO. If they want high-hp speed trucks - then fine, go the way of the Lightning and SRT Ram. But don't dope-up the regular work truck and try to make it something it should not be. :no:

Another thought on the Hp v. Tq discussion...

Do you guys understand that you can gear a car (or truck) to make MORE Tq at the wheel, but not more Hp?
I guess a better way to say this is that for any given engine, you can alter the gearing - via transmission ratios, rear axle ratios, and even wheel/tire diameter - and actually multiply or reduce the torque value acting between the tire and the asphalt.
But the actual horsepower value will not change via gearing or ratios. :no:

What this means for the average driver is that you can gear your car in a way such that you can overcome a Hp deficit for a short period of time. Any 5.0 driver realizes the benefit of dropping in a set of 3.73s to replace the 2.73s most cars came with. It made the 5.0 with 225hp competitive on the street with cars having 285 or even 320 hp. It was the first mod most 5.0 owners did to get "serious" about launching, and it made the 5.0 a wicked player for stoplight jumps and 1/8th tracks.
Of course the down-side to this was that you run out of wind on the top-end, and the cars able to make the Hp and run lower gears to boot simply drive away. Also a fact many 5.0 owners are aware of.

It goes back to the point I made about torque being independent of time (completely) whereas power is time-dependent.

And to contradict what has been said earlier - you CAN have Torque without Power.

Suppose you have a bolt that is welded to the plate it was screwed into (go with me on this).
You put a wrench on the bolt and apply 100 ft-lbs of torque to the bolt, but it doesn't move because it's welded.
You ARE putting 100 ft-lbs of torque on that bolt - no doubt!
The torque wrench tells no lies.
You can apply that force (torque) for minutes, hours, days... but it won't move.
Until it moves, you have not completed any WORK (force through distance), or used any POWER (work per unit time).
So you can have torque without power, but you can not have power without torque.
Which of the two "sounds" more important to have?

Things that make you go "Hmmmmm".

Another thought on the Hp v. Tq discussion...

Do you guys understand that you can gear a car (or truck) to make MORE Tq at the wheel, but not more Hp?

That is incorrect ;)

Torque can be measured at the engine, and it can be measured at the wheels. Similarly with horsepower.

HP = (TQ x RPM) / 5252

That's the formula. If you alter TQ, you alter HP. When you alter gearing, you modify TQ at the wheels, but not at the engine. And your wheel HP will be modifed as well, not engine HP.

What you're talking about is the total work done by the engine may not change. This is difficult to achieve/measure, as that depends on the total area under the graph (you need to use integration).


And to contradict what has been said earlier - you CAN have Torque without Power.

Incorrect as well ;). You are applying 100 lbs of force, but you do not have torque. Torque is the force that produces rotation. It causes an object to rotate. Without rotation, you got no torque.

Physics, engineering and all that jazz gets funny when you get into details and work with actual definitions of words.

Back on the Ford Trucks... My friends who lives and breathes Ford belive that they are going to go back to a push-rod style motor starting in the trucks around 09-2010.

Back on the Ford Trucks... My friends who lives and breathes Ford belive that they are going to go back to a push-rod style motor starting in the trucks around 09-2010.

Boss isn't a pushrod... it's a SOHC 2v
So that would be a negative.

That is incorrect ;)

Torque can be measured at the engine, and it can be measured at the wheels. Similarly with horsepower.

HP = (TQ x RPM) / 5252

That's the formula. If you alter TQ, you alter HP. When you alter gearing, you modify TQ at the wheels, but not at the engine. And your wheel HP will be modifed as well, not engine HP.

What you're talking about is the total work done by the engine may not change. This is difficult to achieve/measure, as that depends on the total area under the graph (you need to use integration).
I'll debate with you til pigs fly on this one friend.
Suppose you have 100ft-lbs of Tq at 100rpm from the engine.
In case #1, we have a 1:1 drivetrain with no efficiency losses, so 100ft-lbs make it to the pavement at 100rpm tire speed.
If you change the rear gear to 2:1 and run the engine at the same speed (100rpm), you will get 200 ft-lb of torque, but you will only have 50 rpms at the tire.
According to your own equation... at the wheel...
Hp1 = (100*100)/5252 = 1.904hp
Hp2 = (200*50)/5252 = 1.904hp
Hence, DOUBLE the torque, but SAME horsepower.
Just like I said. ;)

The engine can NOT make any more power - regardless of how you gear it. :no:
But you can change gearing around all you want and play games with the Tq. :yes:
You err in what I highlighted in red.
NO gearing change can affect total power in a common driveline. :no:
Law of Conservation of Energy ---> Power in = (Power out - losses of efficiency)



Incorrect as well ;). You are applying 100 lbs of force, but you do not have torque. Torque is the force that produces rotation. It causes an object to rotate. Without rotation, you got no torque.

Physics, engineering and all that jazz gets funny when you get into details and work with actual definitions of words.
NO, without rotation you got no WORK.
Work = Forcee through distance and/or torque through rotation.

I'll contest you til pigs fly on this one too.
Torque is a force applied at a distance from a center of rotation.
That applied force (or torque) does NOT have to result in movement to exist, the unique thing is that it is being cancelled by another (reaction) force... but it DOES exist.
What is still at a value of zero is the WORK done, because work is dependent on movement or displacement. No move, no work.
Since power is work per unit time, no work, no power.

You see, in the totality of my simple example, we neglected to account for things that are "given". If we do a summation of forces about the center of rotation, we simply find that the applied force (that we are putting on the torque wrench) is being countered in the opposite direction by the bonding forces of the weld at an atomic level. In other words, there is a "reactive" force that is countering the one I am applying. Sum of forces = 0, so no acceleration, no move, no work, no power, but the applied force (Fa) is VERY real.

Now if you really want to get into micro-statics, we have technically deflected the bolt at a microscopic level, and it has in fact rotated a miniscule amount, but not so much that it has overcome the Van der Walls forces and resulted in permanent deformation of the steel. It will in fact flex back to it's original position when the pressure is released, so what we have really done is stored some potential energy in the system while it was deflected, and released that energy when we removed the applied force, still resulting in a net work of 0, and net power of 0. ;) :cool:

Back on the Ford Trucks... My friends who lives and breathes Ford belive that they are going to go back to a push-rod style motor starting in the trucks around 09-2010.

I'll be surprised.

One thing all the complexity of OHV engines does allow is varied valve timing and combustion adjustments. As fuel regulations change and emissions get ever harder to comply with, I suspect that alterior benefits will become more profound in OHV engines in the future.

I further suspect that combustion engines will basically evolve through OHV configurations until they are replaced by hybrid and eventually electric motors.

I see the future of pushrod engines as dim. Not snubbed out, but dim.
The LSx series from GM flies in the face of conventional pushrod theory, but even those magnificent engines have design limitations.

Thats true but they just can't keep up with the power without adding a blower. I'll call my friend i got this from a little later and see if i can get more info.

...What this means for the average driver is that you can gear your car in a way such that you can overcome a Hp deficit for a short period of time. Any 5.0 driver realizes the benefit of dropping in a set of 3.73s to replace the 2.73s most cars came with. It made the 5.0 with 225hp competitive on the street with cars having 285 or even 320 hp. It was the first mod most 5.0 owners did to get "serious" about launching, and it made the 5.0 a wicked player for stoplight jumps and 1/8th tracks.
Of course the down-side to this was that you run out of wind on the top-end, and the cars able to make the Hp and run lower gears to boot simply drive away. Also a fact many 5.0 owners are aware of.
...

But what happens when the guy that has 320 HP...say...a 99 Cobra....goes from 3.27s to 4.56s? :)

We gotta hook up sometime at a show, meet, or race....you're only about 4 hours SE of Va Beach.

Bob

PS....I'm selling my Hog, and will likely bring an old friend (http://members.cox.net/bobcosby/cobra/images/cobrasep03-1.jpg) back into the garage. :)

You use gearing to make up for torque deficits, not HP deficits. That is why you can have a Formula 1 car that makes only a couple hundred ftlbs of torque at the motor have very high instant acceleration values. Although they are only displacing 2.4L, they rev to 19,000 RPM, and could tow any size trailer of hay bails if you geared it right and had the right clutch (or an auto). :)

(Of course F1 cars weigh nothing, but that isn't the whole story).

I'll debate with you til pigs fly on this one friend.


I stand corrected on both counts. First, my definition of torque was not correct, I thought motion was required.

Second - i didn't take into account varying RPM (duh - it's in the formula), but that's because i was thinking more of cars, gearing and dyno.

I remember my grade 12 physics teacher telling the class to lift up our chair. He said while we're lifting, we're doing work. He would pay us for working. Once we lifted it, he said to keep the chair lifted. We were not doing any work and he would not pay us for holding the chair. That was a funny way to illustrate definition of work in physics.

Thats true but they just can't keep up with the power without adding a blower...

I can't go along with that.

GM's 4.8 runs 295 horsepower and 305 torque. The current 4.6 in the Mustang runs 300 horsepower and 315 lbs/ft of torque.

Move to the GM 5.3 and you're talking 320 horses and 340 torque in top tune. Meanwhile, the latest Ford 5.4 Triton makes about 300 horses, yet belts out 365 lbs/ft of torque.

In both instances Ford not only keeps up in power, they arguably set the bar and set the pace in power at displacement.


You make the mistake that's often made when comparing GM's pushrod and Ford's cammer engines. People tend to throw everything Ford makes against GM's larger 5.7, 6.0, and 6.2 engines, despite them being smaller in displacement. Ford substitutes larger displacement with more cams and/or a supercharger and has arguably done a splendid job at it when you pit the blown 4.6 against a GM 6.0 or 6.2 engine (remember, the blown Cobras were underrated by at least 20 horses). The blown 5.4 (an engine barely any larger in displacement than the small V8 in the Impala SS) puts out as much horsepower as the Chrysler SRT V10, and is structurally capable of putting out significantly more.

Give credit where credit's due.

GM is great at getting high fuel economy and amazing life out of large V8 pushrod engines. But Ford's OHC V8s are by no means behind the curve.

Though the Ford V8s do have drawbacks (mainly cost to manufacture and physical size due to the massive heads on them) saying they can't make the power without a blower is false. Displacement to displacement, and the fact that Ford spends the extra money on forged internals, their engines put out the power.... and are friendly to blowers to boot.

But what happens when the guy that has 320 HP...say...a 99 Cobra....goes from 3.27s to 4.56s? :)

Another factor is the use of the power curve. Using 4.56s instead of 3.27s allows the car to stay near the power peak for a longer period of time.

But what happens when the guy that has 320 HP...say...a 99 Cobra....goes from 3.27s to 4.56s? :)

We gotta hook up sometime at a show, meet, or race....you're only about 4 hours SE of Va Beach.

Bob

PS....I'm selling my Hog, and will likely bring an old friend (http://members.cox.net/bobcosby/cobra/images/cobrasep03-1.jpg) back into the garage. :)
Well, when a car with 320hp puts 4.56:1 gears under it, he becomes able to reach 6000 rpms REAL fast, and keep it there while changing gears, and he essentially rapes anything with less Hp until he reaches about 135-140! :D
Interestingly, in cases like this the top speed of the car will likely be limited to engine revs, not the Hp of the engine.
Name of the game in drag racing is to get your car to it's Vmax by the end of the 1/4, right? Gearing is the most direct way to accomplish that - no doubt.

In all seriousness, you are multiplying your torque by 4.56, where others may be using 4.11 or even 3.91, and that multiplication is what is getting your car out of the hole even quicker. For another car to even be competitive, it would need @ 320hp AND at least 11% more torque you do if he runs the 4.11s, and he would need about 17% more torque if he runs the 3.91s. So it would actually be a neat race between 320hp/317tq running 4.56s and another car with 320hp/370tq running 3.91s... provided the tq of both engines is decently close in rpm range.

Aside - My sister and bro-in-law were stationed at NAS Oceana for 8 years, mom was raised in Norfolk (went to Murray High School), dad was based out of Norfolk docks while on the USS Amphion. We kept an off-shore sportfishing boat docked in Little Neck for years. I know Rudy Inlet like the back of my hand. I know Va. Beach pretty well. I'll drop you a note next time I'm headed that way. :cool:

As it turns out, I am heading to Richmond, VA for 2 days, staying tomorrow night (installing test equipment at one of our equipment manufacturers).
Likewise, I am trying to schedule another track event at VIR for the last weekend in June. Our local SVT Cobra Club has reserved the track for the weekend and I am invited - I just need to be sure I'm not shipped out to China or Europe before I register. VIR would be a great place to hook-up... it's between Danville and South Hill, VA off hwy 58.

I'd love to meet up with you and have a cold one - my treat.:thumb:

Good luck on the Whine Maker.
I couldn't believe you let it go after winning the title. :no:

I stand corrected on both counts. First, my definition of torque was not correct, I thought motion was required.

Second - i didn't take into account varying RPM (duh - it's in the formula), but that's because i was thinking more of cars, gearing and dyno.

I remember my grade 12 physics teacher telling the class to lift up our chair. He said while we're lifting, we're doing work. He would pay us for working. Once we lifted it, he said to keep the chair lifted. We were not doing any work and he would not pay us for holding the chair. That was a funny way to illustrate definition of work in physics.
Peace, love, and happiness! :bow: to you.

I don't care about who is right or wrong. I just want us all to come away with fresh perspectives or maybe even learn something new from each other while we all chisel away at the myths that proliferate on the internet so wildly.

The two courses I enjoyed most in Engineering were Statics and Dynamics... I made straight A's under a pretty tough professor. Dr. Richard Dubler worked for Eastman-Kodak when they were developing cameras and satellite imagery systems in the 1970s. He brought practical application to the textbooks, and I will never forget his courses. I stay in touch with him to this day.

I love this junk... these are the things that led me into machine design as a career. :shrug:

I can't go along with that.

GM's 4.8 runs 295 horsepower and 305 torque. The current 4.6 in the Mustang runs 300 horsepower and 315 lbs/ft of torque.

Move to the GM 5.3 and you're talking 320 horses and 340 torque in top tune. Meanwhile, the latest Ford 5.4 Triton makes about 300 horses, yet belts out 365 lbs/ft of torque.

In both instances Ford not only keeps up in power, they arguably set the bar and set the pace in power at displacement.


You make the mistake that's often made when comparing GM's pushrod and Ford's cammer engines. People tend to throw everything Ford makes against GM's larger 5.7, 6.0, and 6.2 engines, despite them being smaller in displacement. Ford substitutes larger displacement with more cams and/or a supercharger and has arguably done a splendid job at it when you pit the blown 4.6 against a GM 6.0 or 6.2 engine (remember, the blown Cobras were underrated by at least 20 horses). The blown 5.4 (an engine barely any larger in displacement than the small V8 in the Impala SS) puts out as much horsepower as the Chrysler SRT V10, and is structurally capable of putting out significantly more.

Give credit where credit's due.

GM is great at getting high fuel economy and amazing life out of large V8 pushrod engines. But Ford's OHC V8s are by no means behind the curve.

Though the Ford V8s do have drawbacks (mainly cost to manufacture and physical size due to the massive heads on them) saying they can't make the power without a blower is false. Displacement to displacement, and the fact that Ford spends the extra money on forged internals, their engines put out the power.... and are friendly to blowers to boot.

D@mn-good post. :bow:

Both engine designs have their virtues, and another internet myth goes "poof".

As it turns out, both GM and Ford look kinda bad when you look at import V6's that are making 260-320hp naturally aspirated. :(
At least they are not making piles of torque, but as I stated about the Matrix and MiniCoopers at the recent track event - it blows my mind how well these little cars are performing lately.
THOSE engines are the benchmarks for daily drivers these days.

Takes me back to a comment made months ago about GM, Ford, and Chrysler needing to stop shooting at each other so much and look at the rest of the playing field instead. We may find out that our rivals for the past 40 years should now become allies and we need to look at the implants coming into our yard from abroad as the new enemy. :think:

Ok the Ford going back to pushrods was in an artical in 5.0 magazine. Also, everyone knows that mod motors don't make **** NA. And GM now has a 300HP direct injection V6 that will be in acrs either this year or next i belive starting in caddilacs. As for the big three becoming allies, there are rumors of GM buying out Chrystler. It seems the Germans aren't very happy with them and acutauly want to drop the brand completely.

Ok the Ford going back to pushrods was in an artical in 5.0 magazine. Also, everyone knows that mod motors don't make **** NA. And GM now has a 300HP direct injection V6 that will be in acrs either this year or next i belive starting in caddilacs. As for the big three becoming allies, there are rumors of GM buying out Chrystler. It seems the Germans aren't very happy with them and acutauly want to drop the brand completely.

GM won't buy Chrysler - I promise.
I would like to see the big 2.5 develop more alliances or joint ventures together, but not integrate into one big company. :no:

I still don't know where you are getting your facts about Ford mod-motors though. :shrug:
guionM did a good job of showing numbers already.
The guy I have been posting with - Bob Cosby - he can tell you better than anyone on this board what an n/a mod-motor can do. He's got this shiny thing on his mantle at home that he won with his n/a mod-motor running it for a long time, in lots of places, against lots of competition - push-rods and otherwise. ;)

Hey Bob, you up for this one?

Originally Posted by ProudPony:
In all seriousness, you are multiplying your torque by 4.56, where others may be using 4.11 or even 3.91, and that multiplication is what is getting your car out of the hole even quickerDoesn't that reduction in time equate to an increase in power, net power?
Letting your "engine" reach peak power faster, or what is horsepower limited to, just engine components?.....it makes for an interesting discussion...

Doesn't that reduction in time equate to an increase in power, net power?
Letting your "engine" reach peak power faster, or what is horsepower limited to, just engine components?.....it makes for an interesting discussion...
Nope, no increase in power.

For any closed system, power in = power out (less losses to inefficiencies).

Taller gears will allow you to get to max Hp levels quicker as far as engine RPM goes, but it also takes you through peak Tq faster putting you on the Tq drop-off line sooner.

Think of this... Power = Torque * rpm
Taller gears make Tq go up, but wheel speed go down
Shorter gears make Tq go down, but wheel speed go up
In either case, Hp will remain constant. You can only change the ratio between Tq and rpm via gearing, you can NOT change their product. ;)

Bottom line, you can play with gears to adjust torque, but not power.
The power made by the engine will always be the same regardless of tranny or rearend ratios.

It is neat, isn't it?
This is why NHRA and NASCAR teams now have dedicated engineers on their teams to maximize the benefit of the engine's output at the pavement for any given track or course. Pneumatic clutches, limited slip, traction lok, etc. - it all comes into play in getting the engines total output to the ground most effectively.

Daily street cars - WHOLE different story.:)

Also, everyone knows that mod motors don't make **** NA...

You obviously didn't read my post and haven't looked anything up on your own (let alone question "everyone"), have you??

Don't just live life repeating someone else's ridiculous myths & rumors, my friend. Check out things for yourself. ;)

Nope, no increase in power.

For any closed system, power in = power out (less losses to inefficiencies).

Taller gears will allow you to get to max Hp levels quicker as far as engine RPM goes, but it also takes you through peak Tq faster putting you on the Tq drop-off line sooner.

...
Bottom line, you can play with gears to adjust torque, but not power.
The power made by the engine will always be the same regardless of tranny or rearend ratios.

It is neat, isn't it?
This is why NHRA and NASCAR teams now have dedicated engineers on their teams to maximize the benefit of the engine's output at the pavement for any given track or course. Pneumatic clutches, limited slip, traction lok, etc. - it all comes into play in getting the engines total output to the ground most effectively.

Daily street cars - WHOLE different story.:)

The gear ratios CAN allow you to use the power more effectively.

The number of gears also plays a factor. Every time you shift, you are no longer applying power to accelerate. Therefore, you also want to minimize the number of gear changes. That's why 2-speed powerglide transmissions are so popular in purpose built drag cars. Lenco transmissions are also popular due to the fast gear changes.

Theoretically, you would make as much power as possible with your engine (RPM doesn't matter). You would then use a CVT to constantly adjust the torque multiplication and the speed of the vehicle.

However, due to the torque limitations of CVT transmissions, you have to use a geared transmission. Drag racers adjust the ratios to keep the engine as close to the horsepower peak as possible.

The other limitation is traction (or friction). A lot of times, reducing the power output will result in a faster 1/4 mile time, since you will actually put more power to the ground. (sliding friction versus rolling friction)

Top fuel dragsters don't even use a transmission! They use a series of clutches. They run the engine at basically a constant speed, but slip the clutches as the vehicle accelerates.

The gear ratios CAN allow you to use the power more effectively.
Absolutely!
And that use can be for mileage, to finish the 1/4 as fast as possible, top speed in the salt flats, or accelerating from 50 to 120 as quick as possible numerous times - it all depends on what you are wanting to do.
As HAZ-Matt pointed out, we COULD use a turbo I4 from an Indy car spinning 19k-rpm to pull plows in a hay field if we geared it properly. Will that be the most efficient way to do it? Probably not, but we COULD do it.

The number of gears also plays a factor. Every time you shift, you are no longer applying power to accelerate. Therefore, you also want to minimize the number of gear changes. That's why 2-speed powerglide transmissions are so popular in purpose built drag cars. Lenco transmissions are also popular due to the fast gear changes.

Theoretically, you would make as much power as possible with your engine (RPM doesn't matter). You would then use a CVT to constantly adjust the torque multiplication and the speed of the vehicle.

However, due to the torque limitations of CVT transmissions, you have to use a geared transmission. Drag racers adjust the ratios to keep the engine as close to the horsepower peak as possible.

The other limitation is traction (or friction). A lot of times, reducing the power output will result in a faster 1/4 mile time, since you will actually put more power to the ground. (sliding friction versus rolling friction)

Top fuel dragsters don't even use a transmission! They use a series of clutches. They run the engine at basically a constant speed, but slip the clutches as the vehicle accelerates.
Good points all. :thumb:

PS - I thought TF cars were using pneumatic clutches with clutch slip controlled by air pressure, some programmable, some manually adjusted. Is there something newer going on there now?

PS - I thought TF cars were using pneumatic clutches with clutch slip controlled by air pressure, some programmable, some manually adjusted. Is there something newer going on there now?

Not that I'm aware of. That's what I meant.

Proud....Danville's quite a hike from here, but you never know! Would be good to hook up.

LOL. Most of us don't make real good power in comparison to an LS1. However, the extra ~1000 rpm allows us to gear much more aggressively, and thus outrun cars that make more RWHP, everything else (minus gear) being equal. That's why you might see a 315 RWHP M5 Cobra run 11.6 @ 3200 lbs, while it takes an M6 LS1 ~350 RWHP to run the same ET at the same weight.

Top speed....and even trap speed...is a whole nuther issue.

Speaking of N/A mod motor HP....good friend of mine runs a stock bore 5.4L 4V in his N/A 97 Cobra. Spins it to ~8500 rpm, makes in excess of 700 HP, and runs 9.3s @ 140+ mph at ~3200 lbs. If you know anything about the 5.4....imagine the piston speed at that kind of rpm. Ouch!! :)

Bob

I understand the HP=Torque*rpm ;) Maybe it seems like it increases total power output from becoming more efficient:shrug:
Maybe that's why the "seat-o-pants" meter registers more than the dyno sometimes.
So a car with 300hp/300lbft @ 3,000rpm will accelerate at the same rate as a car with 300hp/300lbft @ 6,000rpm, if both vehicles were geared for their respective engine? (..all else being equal..)
But only one can be more or most efficient, right?

I understand the HP=Torque*rpm ;) Maybe it seems like it increases total power output from becoming more efficient:shrug:
Maybe that's why the "seat-o-pants" meter registers more than the dyno sometimes.
So a car with 300hp/300lbft @ 3,000rpm will accelerate at the same rate as a car with 300hp/300lbft @ 6,000rpm, if both vehicles were geared for their respective engine? (..all else being equal..)
But only one can be more or most efficient, right?


You can't have 300hp and 300 lbft at both 3000rpm and 6000 rpm.

300 lbft @ 3000rpm = 171 hp.

300 lbft @ 6000rpm = 343 hp.

hp = torque * rpm / 5252.

You may want to re-read what he wrote.

Originally Posted by rlchv70:
You can't have 300hp and 300 lbft at both 3000rpm and 6000 rpm.

300 lbft @ 3000rpm = 171 hp.

300 lbft @ 6000rpm = 343 hp.

hp = torque * rpm / 5252.I know they cross @ 5252, I just tried to pick numbers that would make the math simpler.
Power is also;
Power (hp) = Force (lb) * Velocity (MPH) / 374
I guess I was trying to see if that "power" increased, not horsepower?...since I'm not an engineer, but I can go through the math and see what it tells me.

I found some interesting tid-bits on this:....
Horsepower and Torque
by Matthew Kramer :
Take two engines, one that develops 220ft-lbs from 3,000 RPM to 6,000 RPM and one that only holds its 220ft-lbs of torque from 4,000 RPM to 5,500 RPM. Beyond those ranges, both engines fall off quickly. While they have the same torque from 4,000 RPM to 5,500 RPM (meaning they will accelerate at the same rate then), from 3,000 to 4,000 RPM and 5,500 to 6,000 RPM the first engine has more torque and will therefor accelerate faster. In a race that takes each engine from 2,000 RPM to 6,500 RPM, the first will clearly win, despite the fact both owners can boast about having 220ft-lbs of torque.



Once again, though, it needs to be noted that a car's quoted power is at one specific place in the engine's range of operation. Let's say it takes a certain car 160HP to go 120mph and 200HP to go 150mph. The manufacturer claims the car makes over 200HP at 6,500 RPM. As luck would have it, this car's gearing is set up so that it travels 150mph at 6,500 RPM, which would lead one to believe that this car can do 150MPH, since it has enough HP to reach that speed. However, through lack of engineering, the gearing is setup so that the engine runs at 4,000 RPM at 120mph, and it is only capable of 150HP at 4,000 RPM. The car could never hit 150mph, because it doesn't have the power in the right place to climb pass 120mph.

As RPMs get higher, there is less torque for a given amount of power. For example, compare two engines that make 250HP at their peaks. The first peaks at 5,000 RPM, the second at 7,000 RPM. At the time the first engine is making its peak horsepower, it will be making 263ft-lbs of torque. Where at its power peak, the second engine only makes 188ft-lbs of torque. Even though both engines boast the same peak power, the first is going to have higher torque the majority of its power band, meaning quicker acceleration. This is complicated some by gearing, though, as the second engine has a much longer range of operation before it needs to shift to a slower gear.

Conclusion:

A car's performance isn't as cut and dry as simple peak horsepower and torque statistics. It's mainly a result of the area under an engine's torque curve, a car's weight, and its gearing. Horsepower, it turns out, is really only useful as an indicator of a car's top speed. However, because of the relationship between torque and power, horsepower can also be used as an indicator of the engine's torque band. In the real world, though, the best way to figure out a car's performance is to drive it, or read results from others who have driven it.

The above post explains why a 3500 lbs AWD Audi A4 with a 2.0L turbo 4 engine producing 200 HP is capable of low 15 sec quater mile (actually, some have done even 14.9 @ 94 mph).

Quite mindboggling, as my car (V8, 300 HP, 295 lb-ft of torque, 4000 lbs) does the quater mile in 15.0 (wish it was faster), with nearly 50% more HP and torque.

A simple look at the torque curve of the 2.0T engine reveals that it has a flat curve, delivering 100% of its torque from 1850 RPM to 5500 RPM. I'm sure my torque, being in a naturally aspirated engine, starts off low, peaks at 3500 - 4000 rpm, then dips again.

If only more sources were available for thrust graphs (like some of the motorcycle magazines publish). That takes everything and distills it down to the only thing that matters - how much accelerative force is available at the drive wheels throughout the vehicle's speed range. Alas, we must usually deal only with peak power and torque numbers, which are pretty much useless in and of themselves.

If only more sources were available for thrust graphs (like some of the motorcycle magazines publish). That takes everything and distills it down to the only thing that matters - how much accelerative force is available at the drive wheels throughout the vehicle's speed range. Alas, we must usually deal only with peak power and torque numbers, which are pretty much useless in and of themselves.

Yup.. not to mention the factor of how aggressive the powertrain management will allow the trans to kick up and down, and the throttle and engine to be set for full acceleration, in real life scenarios..

Speaking of N/A mod motor HP....good friend of mine runs a stock bore 5.4L 4V in his N/A 97 Cobra. Spins it to ~8500 rpm, makes in excess of 700 HP, and runs 9.3s @ 140+ mph at ~3200 lbs. If you know anything about the 5.4....imagine the piston speed at that kind of rpm. Ouch!! :)

Bob

:eek:

My biggest complaint of the Mod motors is physical size, and the fact that all the rpm capibilty of an OHC setup seems to be negated (in stock applications) by the undersquare dimension.

You mean that really long stroke negates the RPM potential of the mod motors, the 4v heads flow plenty of air for a 330 CI motor. Oversquare, Undersquare, or Square is not to big a deal - being oversquare helps mind you.

My single biggest complaint is indeed size and weight. Would be nice if they could be bored (easily) too.

Bob