Sure will get you going faster.

 

It will "feel" good on the street, but won't accelerate the car as fast as one with more HP, assuming the cars are geared correctly. Because HP = Tq * rpm, the higher peak tq is, the more HP you will have. This is why Formula 1 engines turn horrendously-stupid rpm (approaching 20,000 rpm these days).

Of course, in a street car, reason must be applied.

 

Wow.


Clearly, a rapier-like insight... if the point wasn't about efficiency... which it was...

 

Wow.

Cleary I didn't meet your requirements for a rapier-like reply....please accept my humble apologies.

Also, you'll kindly forgive me for finding a portion of your post in which I'd like to make a comment - and then making that comment. I'd like to say next time I won't bother, but that simply wouldn't be true.

Instead, I think next time I'll not only comment on whatever it is you said that I feel like commenting upon, but I'll throw in a smart-*** remark like the one you just made (unprovoked).

How's that, buckwheat? Wanna have another go?

 

Hi Bob,

Congrtas on your season so far. I think that is pretty damn cool.
I also saw the article on you in this month's issue of 5.0. If you are pissing that many people off you must be doing something right. Anyway they are saying a bunch of good stuff over on the website that shall remain nameless. Keep up the good work I love reading about the new records and stuff you set.

 

Bob and I see eye to eye on the issue of tq vs. hp. Low end tq is highly over rated. If you have enough to break the tires loose you have too much tq IMO.

 

Boobie... your name associated with humility is kinda like a nun having a great set of breasts...

They might be terrific, but no one ever sees them anyway.


Since fast is a relative term, I got a race for ya...

Your car against a 280hp over-the-road tractor.

Minor change to the norm:

Drag 25,000 pounds behind both of them.

You have more horsepower... but your car will lose... badly. All the while, the diesel will never spin past 2300 rpm.

Area under the curve Boobie... area under the curve.


BTW... F1 motors spin to the moon because they are DISPLACEMENT LIMITED - were the rules to be relaxed, everyone would immediatly switch to higher displacement motors.

 

Well, these days, 4-bangers are making 300+hp. Thats only because of DOHC. The Chevy small block OHC are awesome. But Chevy needs to play some major catch up in the sport compact segment. The ecotech, as we all know, has major potential, but it just doesn't compare to the competion yet. 300+ hp 4-bangers weigh less than powerhouse ls-1/ ls-6's and that leads to a better balanced car.

FWIW, I am still a chevy hardcore fan. My father worked for Chevy for 10+ years before he died. GM gave treated us very well during the whole affair, But, chevy has nothing that competes with my current car. Please, GM, make a 300hp AWD G6 that competes with the EVO. I will buy it. Really.

 

which is why it will never go faster than 60mph and only then after about 10 minutes of accelerating. that's without the extra poundage in tow. to build speed a more efficient engine should BUILD power with engine speed and not the opposit. we all know what the perfect scenario is. a torque curve that stays perfectly flat from 0rpm into infinity. unfortunatly a reality check reveals that one size does not fit all. that's why we have specially tuned engines to fit their purpose best. because as it turnes out, efficiency is a relative term as well.

 

The main reason DOHC engines have an advantage over OHV as far as building power with engine speed is BECAUSE they have multiple cams. with separate cams for intake and exhaust, there is that much extra room to tune the engine so that the maximum amount of air makes it's way through the engine at any given RPM. Variable valve timing/lift will never be as effective in a traditional pushrod engine as it will in a DOHC configuration. that is at least until the dual cams in the block idea turns to reality.

 

I hope the powers that be on this Forum see what is going on here, and take my reply in the correct context.

Forgive me for having fun while doing it.

Here's a present for you. Fits well.

We certainly don't have that problem with you, do we, Mr Superior?

Golly Wally...I bet your gonna hit me something I've never heard before.

Wow. Isn't that relavent? We've gone from trying to chide someone for not sticking to the "efficiency" point to how well you can drag around 25,000 lbs.

Well, why don't you and I just run out and buy a pair of Cummings Turbo Diesels for our cars? They won't be fast (without the added weight) and they might not be efficient, but they sure can drag your in-laws around well.

Pssst....wonder what I could do with some gearing to make up for that inability to pull all that weight? Things that make you go hmm.....

Oh. This is funny. Please sir - preach to me about area under the curve. Falling back in the weeee bit of drag racing I do (and realizing this form of motorsport is far below you)....I run 11.4 @ 117 weighing 3340 lbs on DRs w/356 peak RWHP. Please. Preach to me about area under the curve. I don't get it.

No kidding? Got "duh" in your vocabulary? So what would happen if (when) the technology allowed you to spin those higher displacement motors to the same rpm as the lower displacement motors? What's that? They'd make more torque? Cool! What would that do? Well let's see...torque * rpm = HP. More torque = more HP. More HP = faster car. Awesome thought.

Hey Mr Superior-To-Us-All Injuneer. Here's a good read for you. Likely well below your level, but I digress.

When you're done, let me know how that turbo-diesel is doing in your wundercar.

Thanks.

formulatx....many thanks for the kind words. Uh...what website?

morb|d...thank you for the explanation.

 

Have you guys ever seen an over the road tractor accelerate without anything behind it?

A 500 horse tractor will out accelerate most other cars on the road (excluding corvettes, cobras, ect...) without going over 2500 rpms.

That's with the tractor weighing in at around 12000 lbs.

EDIT: Did I forget to mention the tractor is making around 1900 foot pounds of torque?

 

Howdy.

1900 ft/lbs @ 2500 rpm is over 900 HP - not 500 HP. Which is it that the over-the-road tractor have?

Using 500 HP (which is quite a bit more likely than 900 HP, and is the number you quoted), power to weight is going to be:

12,000 lbs / 500 HP = 24 lbs per HP.

Hmmm...not too good.

For comparison, lets take a typical 4 cyl import: The 2004 Honda Civic. It has a beefy 127 HP 1.7L engine and has a published curb weight of 2670 lbs. Let's saddle it with a 180 lbs driver and make it a nice, even 2850 lbs.

2,850 lbs / 127 HP = 22.4 lbs per HP.

Source

Interesting.

Next thing I'm going to hear is "but it has less than 10% of the big rig's torque, so it CAN'T be as fast!

I suggest reading this. And perhaps this. I've already linked this one.

And yes, I've seen one accelerate. Question for you...have you ever seen one accelerate on the dragstrip? Know what they run?

 

It's not making 1900 torque @2500. That is just the peak torque. And no, I have not driven one at the strip or seen one at the strip. But I have driven one on the road once or twice. A 2001 Freightliner with a 550hp Cat engine. Without a trailor behind it the rig gets up to highway speeds pretty quick.


Notice I said on the road. At the track (1/4 mile) alot of cars would walk away from the rig. Now at a 1/8 mile track the rig would have the advantage (think L98) because of all the low end grunt that it has

 

I disagree. Further, I've never seen an L98 pull "great" 1/8th mile ETs when compared to LS1s (about the same torque and weight, but the LS1 has much better HP).

We can agree to disagree, if you like.