Since Ford F-150 is now last in V8 HP/tq, why don't they make the 6.8L V10 an option?
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Joined: Mar 2002
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From: Yadkinville, NC USA
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 back into the garage.
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 back into the garage.
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.
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.
Good luck on the Whine Maker.
I couldn't believe you let it go after winning the title.
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Joined: Mar 2002
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From: Yadkinville, NC USA
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.
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.
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.
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Joined: Mar 2002
Posts: 3,180
From: Yadkinville, NC USA
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.
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.
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.
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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.
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Joined: Mar 2002
Posts: 3,180
From: Yadkinville, NC USA
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.
I would like to see the big 2.5 develop more alliances or joint ventures together, but not integrate into one big company.
I still don't know where you are getting your facts about Ford mod-motors though.
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?
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Joined: Feb 1999
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From: Springfield,OH. U.S.A.
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 quicker
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
Letting your "engine" reach peak power faster, or what is horsepower limited to, just engine components?.....it makes for an interesting discussion...
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From: Yadkinville, NC USA
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.
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Joined: Mar 2001
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From: The Golden State
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.
Don't just live life repeating someone else's ridiculous myths & rumors, my friend. Check out things for yourself.
Last edited by guionM; Mar 20, 2007 at 12:00 PM.
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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.
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 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.
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Joined: Mar 2002
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From: Yadkinville, NC USA
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.
Good points all.
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?
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.
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.
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?
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From: Knoxville, TN
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
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
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From: Springfield,OH. U.S.A.
I understand the HP=Torque*rpm Maybe it seems like it increases total power output from becoming more efficient
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?
Maybe it seems like it increases total power output from becoming more efficient 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?
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Joined: Dec 2002
Posts: 681
I understand the HP=Torque*rpm Maybe it seems like it increases total power output from becoming more efficient
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?
Maybe it seems like it increases total power output from becoming more efficient 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.