totalmotorcycle wrote:
Ah, here is quote I was looking for:
Where horsepower determines how fast a vehicle can travel, torque at the wheels determines how quickly that speed can be reached.
Mike
That quote is talking about torque at the wheel, which is very different from engine torque. You cannot determine acceleration from engine torque but you can with engine horsepower. There are formulas that you can determine quarter mile Elapsed Time and Trap Speed and the variables that the formula uses is weight and engine horsepower, not engine torque.
If engine torque was determiner of acceleration, Harleys would be much quicker in the quarter mile than a CBR1000RR; which we of course is not the case. That is because engine horsepower determines acceleration, not engine torque.
If you are talking about torque at the wheel, yes that determines acceleration; but that is actually a by product of engine horsepower and gear ratio.
Normally one would compare engine horsepower and engine torque, not engine horsepower to torque at the wheels. The quote you posted by itself can certainly lead to confusion. The latter in this case is simply the former affected by gearing.
To give you an example of how torque at the wheel determines acceleration is:
Car A has 350 HP at the wheel and a final drive ratio of 2.50
Car B has 350 HP at the wheel and a final drive ratio of 3.20
With all other factors the same, Car B produces far more torque at the wheel, thus will accelerate faster than Car A.