Originally Posted by 0HP930
You are actually half right in this case. Max acceleration is always at TQ peak, with the max acceleration reduced as the car is shifted into higher gears.
HP just means that the TQ is available at a high enough RPM to push the car to high speeds and multiply to ludicrous torque in low gear.
F = m * a, where F = TQ in the case of a car.
umm, no, actually i am quite 100% correct in my statement.
max acceleration at any speed is ALWAYS at the power peak, not the torque peak.
it's not the torque the engine produces that moves the car. it's the torque the TIRE produces on the ROAD via gearing that moves the car. and at the power peak, that torque is greatest.
why?
because at the torque peak at any given speed you'd be in a higher gear than at the power peak and you'd have less mechanical advantage from the lower gear ratio.
torque @ axle = torque @ flywheel x overall gear ratio. if you are going 60mph at your torque peak the overall gear ratio would be lower.. and the difference in gear ratio will be bigger than the difference in engine torque at the power peak. if you want to pm me (or if anyone posts a request) i can explain this in MUCH, MUCH greater detail. with hypothetical numerical examples.