Driver's Education
Club Racing
Member List
RSS
Help
04-16-2007, 03:27 AM
bobt993 wrote:
Even on the skidpad at Summit, I couldn't get the rear end to step out on my 996, on wet pavement, without using the throttle. All you get is understeer. I'd bring it up to, I don't know, 25-30 mph, right at the limit in a nice circle, then lift -- nothing! The car stays on the same circle.
This is because in my constant circle, the rear tires were nowhere near the limit of adhesion and the front tires were right at it. If the rear tires had less adhesion, and I lifted like this, then the weight transfer when I lifted should have unloaded the back a little, reducing the rear grip, and the back end would come out. The problem is that the discrepency of front to rear grip is so great to compensate for the fact that the motor is in the wrong end of the car. Theoretically there is some speed that if I were going fast enough that this would work, but at low speeds on a skidpad, my experience is that it doesn't.
A great/fun exercise with PSM on the skidpad is to get the car to understeer with PSM on and to get an understanding of what PSM is actually doing for you in that case. For the most part, you can mash the throttle and it will compensate to allow you to go in whatever radius circle you want. You can also practice driving to the limit right before PSM kicks on.
Quote:You must time such an action and best place to learn is the skidpad.
Even on the skidpad at Summit, I couldn't get the rear end to step out on my 996, on wet pavement, without using the throttle. All you get is understeer. I'd bring it up to, I don't know, 25-30 mph, right at the limit in a nice circle, then lift -- nothing! The car stays on the same circle.
This is because in my constant circle, the rear tires were nowhere near the limit of adhesion and the front tires were right at it. If the rear tires had less adhesion, and I lifted like this, then the weight transfer when I lifted should have unloaded the back a little, reducing the rear grip, and the back end would come out. The problem is that the discrepency of front to rear grip is so great to compensate for the fact that the motor is in the wrong end of the car. Theoretically there is some speed that if I were going fast enough that this would work, but at low speeds on a skidpad, my experience is that it doesn't.
A great/fun exercise with PSM on the skidpad is to get the car to understeer with PSM on and to get an understanding of what PSM is actually doing for you in that case. For the most part, you can mash the throttle and it will compensate to allow you to go in whatever radius circle you want. You can also practice driving to the limit right before PSM kicks on.