Too Much Torque

I was recently looking at the specs on the new Porsche GT2 RS. Really cool car. 700hp and 500 lb/ft torque. It reminded me of a tech tip Tuesday video I made when I owned Dinan about why more torque is not always better. (link to video)

You see, more torque does not always make a car faster. Once you exceed the traction capabilities of the tires they go up in smoke and the car doesn’t go anywhere. This is why dragsters have slipper clutches, the slipper clutch reduces torque to the maximum amount the tire can handle. As the dragster goes faster, and down force increases traction, the clutch reduces slipping and adds power in just the correct amount to get maximum acceleration without breaking the tires loose.

On a street car we have a transmission that increases torque at the rear wheels dramatically for acceleration from a stop. With modern, high-performance turbo cars it is very easy to break the tires loose from a stop and on gear changes. This loss in traction slows acceleration. Most 2WD road cars – even with large grippy tires – can’t handle more than 400-500 lb/ft of torque. AWD cars can handle as much as 600 lb/ft without losing traction.

The smart folks at Porsche reduced torque and increased HP so the 2WD GT2 RS can accelerate as fast as possible. In addition, the car is much easier to drive and more docile at its limit. This is an important lesson in building a well-balanced car, as performance relies on much more than just power and torque.

Steve Dinan

Written by FrancoKahn

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