After my recent PSDS outing in the 991 Carrera S PDK car at Barber, I have been wondering if there are specific driving techniques that will take advantage of the Porsche Torque Vectoring technology. I imagine that adding throttle might accentuate car rotation when this same technique in a 997 might just cause more understeer.

 

Good question, and it should concern every 991 owner, with this option, as you cannot turn PVT off. Never; even if you deactivate PSM.

 

On my Cayenne, PTV helps in providing crisp turn in and steering response that is amazing for an SUV. I drive the car as I would any car; no special techniques, it simply responds better to input and there's no reason I can think of to ever turn it off. Still, what works great on an SUV might be annoying or worse in a sports car or on track. I'd like to think Porsche knows what they're doing and engineered the same seamless reactions into the 991, but....

 

Having trouble rotating the car? Turn the wheel more and add gas and feel the back come around!

 

Can't say that I have even noticed the effect on track--other than I can drive essentially the same aggressive line as I did with the Boxster Spyder.

 

Interesting. I wasn't troubled about rotation but wondered about any driving changes with PTV.

I guess your advice varies with the turn but, for example, in Barber's downhill hairpin Turn 5 wouldn't turning the wheel more and adding gas transfer the weight to the rear and increase the understeer you get in this turn? Many Porsches push wide when out of sorts here.

Does PTV do anything in trailing throttle conditions?

On second thought, maybe with PTV the 991 would turn in more aggressively under throttle application.

 

What happens is that when the car "sees" that you want more turn-in, but the yaw sensors don't read the appropriate change in direction, the car puts break on the inside wheel to transfer power to the outside (rear) wheel to force it to break loose and rotate (actually causing forced oversteer). This sounds scary, but as soon as you straighten the wheel, the yaw sensors go back in check and then diverts power to both wheels (ending the oversteer) and you are now applying effective traction while facing where you want the car to go.

 

I would be cautious of this on a downhill turn or you may end up facing the wrong way it can save your bacon if you are too fast for a corner and need to power slide into it to scrub speed.