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Horsepower sells cars, torque wins races.


jmmy
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It's been proven wrong at the track with real world testing. There was a pretty well written study of this idea about 15 years ago (by car and driver I think) with 2 corvettes. One was a base model and the other an LT-1 from a few years prior. the base model had more torque, the LT-1 had more horsepower. the LT-1 beat the base model every time in the 1/4 mile. The higher torque base model had a better hole shot, and it was neck and neck about 1/3 the way down the track, then the LT-1 started to walk away as they reached the higher RPM's and were done shifting. this is where horsepower prevails.

 

 

Torque is a force

Horsepower is the work beign done by that force over time

 

Higher horsepower means mroe is getting done. Torque doesn't even matter at that point. A motor with 1 ft/lb coudl beat a 300 ft/lb motor in a race as long as it ran more than 300 times more RPM, and had the correct gearing for the job.

 

Kinda like a jack hammer and a sledge hammer, the sledge will hit a lot harder, but the jack hammer does the job a lot faster.

 

The car with more horsepower will win if the cars are evenlty matched and have the correct gearing for their respective power curves. This is why the corvette test was useful, almost identical setups, just different motors.

 

Torque is fun to drive with and is cool to brag about, but horsepower indicates how much work can actualy be accomplished with that force.

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i vaguely remember that episods, but that example also shows power/weight ratio...300 hp XXXtq 1600lb car vs 600hp XXXtq 3200lb car

 

Exactly ... they both have 5.33 pounds per HP. In that kind of race the smaller motor is at it's horsepower power peak at redline at 1000 feet in top gear while the bigger motor was at it's torque peak about 2000 RPM ago...

 

Ever notice how insurance companies rate sports cars by horsepower-to-weight ratios, not torque-to-weight...

 

Why would they do that <_>

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Diesel motors can make a lot horsepower too ;)

 

Diesels are a force to be reconed with in the racing scene as technology develops, diesel fuel provides a very efficent form of combustion, and effiency if done right means more power.

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Exactly ... they both have 5.33 pounds per HP. In that kind of race the smaller motor is at it's horsepower power peak at redline at 1000 feet in top gear while the bigger motor was at it's torque peak about 2000 RPM ago...

 

uhm.......i find that's kind of irrelevant. because you are adding gearing into the mix. what if the bigger motor and smaller motor were both geared to peak at the same distance? wouldnt the lower revving motor have an advantage in a perfect world because of the broader torque curve?

Edited by bmx152
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1000hp...no way around that!

http://www.youtube.com/watch?v=RXqSedWSu2k

 

Pretty much what Chad said...torque is a lot of fun...but it does break things. Horsepower is what I would want if I was racing..

 

Yep, once they got though the gears in that race, it was just a horsepower race. The bugatti probalby weighs over 1000 pounds more, and it still won.

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Chad has got it exactly right. Torque is an amount of work. Horsepower is an amount of work being done over time. More horsepower means more work being done, period. If you gave a 150 hp engine and a 300 hp engine the same amount of work, the 300 hp engine would do it in half the time. Even if the 150 hp had more torque.

 

As far as Audi and Peugeot winning LeMans with diesels, endurance racing is all about fuel efficiency and minimal pit stops. Not only do the diesels have better fuel economy, but you're also talking about two teams who likely invest some of the largest sums of money into their racing programs to ensure their cars are exceptionally reliable, fast, and supported by a stellar crew.

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what if the bigger motor and smaller motor were both geared to peak at the same distance?

 

Horsepower peak? then it would be a dead tie.

 

the example was to show how one car is setup arround a horsepower peak, the other arround a torque peak. notice I used the 2 different terms.

 

Heck, our motors bone stock make their torque peak at 2500 RPM, but their power peak at like 3400. If it's all about torque, why not shift at 2500 to win?

 

Why doe we rev our motors out to win races? because that is where the horsepowe rpeak is reached.

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The answer is in the math. HP = (TQxRPM)/5252

 

Any given engine's HP rating contains more information about the engine than its TQ rating does because HP factors in the engine's TQ and the RPM at which the TQ is made. You get HP by multiplying TQ and RPM and dividing by 5252. You get TQ by directly measuring the force applied to "some device" (engine or chassis dyno usually). HP represents an engine's ability to apply force (do work) over time. TQ represents an engine's ability to apply force instantaneously. The reason car manufacturers tend to advertise HP numbers is because HP numbers mean more. They literally contain more information because you use a formula to arrive at them. When you know HP you can deduce quite a bit about TQ. When you only know TQ, you don't know anything about HP. 1000ft/lbs at 1500RPM is a whole different animal than 1000ft/lbs at 7000RPM. So if you know a car makes 1000ft/lbs of tq, you really don't know anything about its overall performance, but if you know it makes 1000HP, you know it can maintain a high TQ output for quite a wide RPM range, since 1000ft/lbs at 5252rpm would equal 1000hp. blah blah.

 

All things being equal, HP is king, period, because you can take advantage of gearing.

Edited by chiplee
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There is no replacement for displacement...

 

is made for racing a long straight lines.

 

(long trajectories)

 

 

Horsepower sells cars, torque wins race

 

is for all the other, (short trajectories).

 

it comes down to play in where you race,

 

in downtown Velo, city...

 

remember...

 

Takumi's AE86 Hachi Roku ????

 

http://www.youtube.com/watch?v=je8OKV_Ep4w&feature=related

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Heck, our motors bone stock make their torque peak at 2500 RPM, but their power peak at like 3400. If it's all about torque, why not shift at 2500 to win?

 

Why doe we rev our motors out to win races? because that is where the horsepowe rpeak is reached.

that is serious tunnel vision right there.

What happens every time u shift ? Tach/rpm drops. Where ? Figure it out

 

The fundamental basis for bigger displacement motors is what ? Torque, or else we would ALL be riding around with 1.0L motors.... even bigaz semis. Work is work

 

Tune your starquest for whatever you think works, but to argue that torque setups can't prevail is plain stupid. Tell eipquest that. His setup defies everything most here adopt;

Taller gear, 6300rpm redline, oe cam, etc. 10.6sec ET. Plug that into your "formulas".

 

A 600hp/350tq honda B18 and a 400hp/700tq cummins, both in a 7000 pound dually. You honestly think the 600hp will ET lower ? -lol. Hint: it won't even be close

 

Enzo, Banks, Ligenfelter all subscribed to the same.... but, what do they know ?

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