Torque is pretty much what kind of “Power” the engine makes.
Horsepower is torque x RPM / 5250.
So say you have two equal cars, same final drive ratio, same weight, perfect traction, and flat powerband. There is no air resistance.
Car one, Is revving at 4500 RPM. It’s making peak torque at 450ft/lbs. horsepower is 385hp at the wheels.
Car two, is revving at 7000 RPM, it’s making peak horsepower at 385hp at the wheels. Torque is 288 ft/lbs.
Both cars hammer on it. What’s going to accelerate faster at that very moment in time.
a. Neither, both cars have the same horsepower
b. Car one, it has more torque
c. Shut up.
I guess what I’m really asking is… Whats acceleration(from a roll) more dependent on, horse power or torque. It’s really hard to ask a question like that because there are about a thousand real life variables.
You’re not really giving us enough information about the car situation.
To answer the second part added on:
Torque is a function of horsepower. Acceleration is a function of horsepower and torque. Therefore the answer to your question is YES.
It’s really hard to word the question… I just want to know what makes a car accelerate from a roll faster if they have pretty much every variable the same. With exception to different torque, yet similar horsepower.
j/k. All else equal, a car putting more torque to the wheels is going to accelerate faster.
If you really wanted to “solve” this you would need calculus: a graph of the car’s torque output vs rpm, speed vs rpm, mathematical models of each, then throw it all into some ccalculus.
torque gets the car going, horsepower keeps it going. Acceleration is a function of them both. Since both cars have the same HP, the car with higher torque assuming all other factors are the same (i.e. weight, wheel size, tires, etc)
Torque is the only that matters. Horsepower is nothing more then a mathmatical function of torque, as stated. Whereas torque is an actual measure of force.
Not that I’m arguing with you (as you’ve got me well outranked)… but it’s always been my understanding that:
Otto ICEs create pressure, which is converted to torque by the crankshaft, and thus sent to the flywheel, tranny, etc etc. We’re skipping thermo / pumping / frictional losses for the moment here.
Basically BMEP & CID -> Torque.
Torque @ a given engine speed -> HP.
torque will give u the jump, HP will give u the top end, but it all depends on where in the powerband they are making their peak values. Even tho u mentioned the final drives are the same, if one car starts at a different RPM from the other, their gearing is still different, and hence their torque multiplication and tq measured at the wheels will be different.
All this calculus and physics is fine and dandy, but just look at the power graph, factor in the gearing, factor in the weight, and u can figure this out pretty easily (power:weight) You’ll never have two exact same cars with no air resistance and perfect traction, so no matter how accurate u are on PAPER, real world apps are always variable