Until recently, I only though horsepower and weight were the determining factors of whether you would win a race or not. However, I have this redneck friend. He has a '70 chevelle and is big on cars in ****. Anyways, he told me that torque is the only real number that you should look at and that "horsepower is just a comparison." However, the only reason I don't believe him is that some heavy-***-duty trucks like an f350 or something produce about 350hp with 900 ft-pnds of torque, but its not a bullet.

 

HP is a function of torque. I recently saw a 55 Chevy with a 502 dyno only 380 rwhp but it made 663 lb/ft of torque. It ran low12's at 118 with a mild 3.73 rear end. My point is you can have a high hp or hi torque car and still be fast, the entire car as a whole and how it is set up that determines if it will be fast or not.

 

Could someone explain to me how going for a lower (numerically higher) differential is explained as taking advantage of "Torque Multiplication"?

and would it be true that two cars, with identical stock rear end ratios (3.27 for exampe) would benefit differently if they both upgraded to say a 4.10 the only difference being one had a much greater torque rating?

 

torque for acceleration HP for top speed is how i see it...

Mustang is a car made to take people from a stop cuase you have and where from 225 to 300 hp but buckets of torque from 300 to 315

 

thats basically a very simple way of saying it, but theres really alot more to it than that. http://www.google.com/search?hl=en&q=hp+vs.+torque

 

horse power is how fast torque occurs!

 

After reading as much techno babble as I can tolerate, the way I have come to understand it is torque gets you going, and horsepower keeps you going.

As an example, I've driven a 4 banger Ranger with loads of torque and no HP, and a Civic with loads of HP and no torque. The Ranger will lurch off the line with authority but then it has nothing after about 2000rpm. The Civic has nothing off the line but it will continue to pull all the way to redline. Now, as you add weight, the Civic loses acceleration steeply, however the Ranger will lose it's accel rate much slower. You could extend the comparison to observe the difference in a motorcycle and a semi. The motorcycle is fast as hell, but only 'cos it weghs almost nothing. A semi won't accelerate well at all unless you compare a semi pulling 20 times it's own weight and a motorcycle doing the same.

So, neither one is paramount over the other. They are both linked like siamese twins, and the task at hand determines which twin you ask to help you.

I don't know if that helps you, but I killed a lot of time writing it, so it helped me since I'm at work. lol

 

HP= torque x RPM / 5250 , if you look at dyno charts, torque and HP always intersect at 5,250 RPM. Some cars that produce high HP have low torque but high RPM like the ricers. Big blocks don't rev that high but have a ton of lowend torque.

Gears multiply torque, so if you have 300FT LBS at the crank,, to the tires you'd have 1,200 LBS with 4:1 gears and 900 FT LBS with 3:1.

 

torque gets you there and horse power keeps you there that is about the most simplest way to explain it.

 

I'll explain whatever you want if you tell me who's in your avatar!!! j/k...

Stock gears, say 2.73's, mean your drive shaft spins 2.73 times to rotate your rear wheels 1 revolution. Going to 4.10's means it spins 4.1 times to make the same 1 rev. w/ the rear wheels. The lower (numerically higher) gears put less load on the engine and make it rev faster to achieve the same thing, so 4.10's put you in your tq range faster. But, your gears will all also be steeper and you'll won't have as high of a top end.

As for the 2 cars, if they both went to 4.10's and were identical (except for the one w/ more tq), the one w/ the tq would get off the line faster.