700 HP R35 GTR vs VEYRON Street race.

[1320-20V]

@hybrdthry911

even though those numbers are at the wheels, the dyno takes into account the different gearing and recalculates the numbers. so when you change gearing the hp and torque on the dyno should be close.

now when you are actually measuring torque on a dyno, like a dynapack, then you can see the raw torque output which can be several times that which you see on a typical dyno chart. the raw numbers will change with gearing but again when it displays the typical dyno chart you see the gear ratio is calculated and factored into the equation.

I’m not sure what you are responding to here. What you said is correct but I’m just not sure why you said it.

Torque moves the car. Torque by definition is force x distance.

If you have 1 ft/lb coming out of the engine (at any speed) it goes into the transmission and the transmission exchanges rotational speed for increased torque. The same thing happens in the ring and pinion. Eventually you have axle torque.

The axle torque is then divided by the distance from the axle to the ground. If you pay attention to units here you will notice your torque is now a force. This force is what is known as the tractive effort, and is the force that directly propels the car.

From this point you can use classical dynamics and the mass of the car to determine acceleration, velocity, and displacement. All of these relationships are derived from F=ma.

Horsepower is only useful for gearing down to create more torque. You can have the high hp/low torque of a honda, or the high torque low HP of a diesel and both can be very fast. That’s why the only thing that matters is mass, axle torque, and the distance form the axle to the ground. You can wrap up the axle torque, and distance to the ground with the simple term of tractive effort.