Better 1/4's..more HP, or TQ...this may be dumb..

trinity_gt said:
The 400HP car will walk the 200HP one. The ability to cover a large distance in a short time will be determined more by HP than not torque. As time and distance open up, HP becomes the dominant term since it's measuring the ability to get work done.

Look at an F1 engine. These things make 800HP or more at 18,000RPM but produce comparatively small torque numbers...assuming 800HP@18000, torque is about 233 ft-lbs and its peak is probably not alot more than that. Yet an F1 car is capable of astounding 1/4-mile times and not just because they're very light. Anyone that's been within 100 feet of one at full song knows the brutal, visceral nature and potential of these things.

They make about 1500 @ 15000 rpm or about 300 lb ft of torque, in a 1000 lb car, that is a lot of torque,considering our cars weigh 3000 lbs and oly have 300 lb ft.
 
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ponysarepretty said:
They make about 1500 @ 15000 rpm

Naw, not 1500. The old turbo cars in qualifying trim came close to that (in race trim they were closer to 1000) but the new ones are definitely lower than this.

or about 300 lb ft of torque, in a 1000 lb car, that is a lot of torque,considering our cars weigh 3000 lbs and oly have 300 lb ft.

:Word: Regardless of the absolute numbers, the power- and torque-to-mass ratios of F1 cars are just incredible.
 
ponysarepretty said:
powerband can't be equal with the parameters you gave, a car with 200 hp and 400 lbft would not be revving any higher than 3000 rpm. While a Car with 400/200 would be revving a lot more than 10,000 rpm, just by nature of how hp is calculated. Torque is the true measure of power, however you have to take into consideration, a 10k rpm car can be geared 3x as high as the 3000 rpm car without detriment to shifting points (so basically a 2.00 rear end vs a 6.00 rear end).


yes this is a great answer
 
hp makes the car gain speed quickly while torque makes it FEEL fast. Assuming the 400hp car is able to get into the power band off the line (slipping the clutch, a high stall converter, ect) it will own the other car all day long.
 
I think the only thing missed is power under the curve. That is what is most important. I work for a dyno and have seen 9.9x cars weighing 3000#'s putting down only 400rwhp. These kind of cars have awesome power bands and thats part of the reason they get down the track fast. An S2000 has 240bhp@7800rpm and weighs 2835lbs, an '06 Stang has 300bhp@5750 and weighs 3500lbs. 11.81lbs/hp for the Honda and 11.66lbs/hp for the Stang. That .15lbs/hp difference is not going to account for the 1+ second in the quarter mile. We have tuned many cars that lose a few peak HP/TQ, in search for a more broad TQ curve. I tuned my car and lost 15 peak hp, to gain torque accross the curve in my car and picked up .2 in the quarter. So to sum it up, it's been my experience that peak numbers are not as important as power under the curve.

Chris
 
Tq = The ability to actually turn the wheels. HP=Time it takes to generate torque. In your example, the 200hp/400tq car can generate massive wheel turning power. Unfortuantely, it does it slowly. The 400hp/200Tq car generates only half the power, but does it twice as quickly. (OK, its not a prefectly linear relationship, but we'll pretend for simplicity) All other things being equal, the 400hp car is going to be getting into the powerband more quickly in each gear. As long as the cars are not so heavy that the 400hp/200tq car doesn't have enough power to move itself, it will win.

The lack of torque is why 4 bangers are typically geared so short. They need to get up in the revs quickly where they have at least some power.

In my many years of trying to figure this relationship out, this is the understanding I've come to. If I'm wrong, don't tell me!! I'll wind up naked in a tower with a high power rifle!