Z356

CA dealers are all getting their 'Launch' 991's this week for the 'unveiling' party at dealerships on Saturday, Feb 4th. At least in the case of Porsche of Monterey, their first two additional customer-ordered 991's coupes will also arrive at the dealership next week. These two are already at port in San Diego and are waiting for the party on Saturday before being released to dealers and their individual customers next week! z356 (Carmel)

Abby Normal

I'm in Newport Beach and will be doing some 991 track driving tomorrow for the launch training. Have driven our launch vehicle around town but really looking forward to some high speed opportunities!

Mike in CA

All due respect, but that's not how PTV works. By applying momentary pressure to the inside rear brake at the beginning of turn in, the system creates a torque differential between the rear wheels, supplying additional rotational force to the car, and sharpening steering response. The system is not capable of making corrections in mid corner if you've gone in too hot, as you described. It actually works very well doing what what it's designed to do; I have it on my Cayenne S.

Whether one wants it on a sports car is another discussion. In the circumtstance you're relating, though, maybe PSM intervened to save you in the middle of the corner, but it wasn't PTV.

Gnslngr

Nope. I wasn't too clear, but by coming in a bit hot my line was poor. The PTV corrected that. Sorry I wasn't more detailed in my post.

fbroen

Edit -- wrong thread post. Pls pardon a newb.

Mike in CA

Still, as I understand it, PTV won't correct your line. PTV activates only the rear inside brake upon corner entry. All it can do is help the rear of the car rotate to the outside of the turn thus reinforcing and enhancing the steering input. There is virtually no ability to "correct" as no other wheels/brakes are affected and the rotation of the chassis is only affected in one direction. With the car coming into the corner on a bad line, if anything PTV could make things worse when you turned in with the car out of shape. At that point PSM, which does have the ability to affect all 4 wheels, would take over and apply brakes at the appropriate wheel(s), and control traction via ASR and ABD to get the car back into a stable state. No doubt there is a fail safe to prevent PTV from engaging in situations where it could cause a problem.

Gnslngr

Okay. But the gentleman from Porsche N.A., who was in the car I was driving, noted what happened and said, "That was PTV right there". Thus, I believed that it was in fact PTV that corrected my mistake. Perhaps it was merely posturing by Porsche N.A., or perhaps he doesn't know what he's talking about. Or perhaps I have failed to adequately explain what happened. Nonetheless, the point in the original post is the same.

Rushman71

As long as we are getting all technical here I would say that's also incorrect. Torque vectoring works to create an additional source of yaw inducing force in addition to the steering. It doesn't do anything to move the back of the car to the outside. By braking the inside wheel, drag is created and subsequently more power is sent to the outside wheel. Essentially, it's the same principle by which a tank steers. So now the car can create more rotational acceleration around its axis than by the forces generated by the steering alone.

Mike in CA

If you read my original comments on this subject (post #63) you'll see that I said pretty much exactly what you just said. I rephrased things in my follow up post, and muddled the issue a bit in attempting to simplify the language. The real life effect of PTV braking the inside wheel is that the car rotates more easily in the direction that the wheel is pointed. That's it. It's not capable of making corrections if the car gets out of shape and that was the main point of both my posts.

Rushman71

No worries, I'm just super **** when it comes to these things! The main point of your posts is absolutely correct and as you said, it's actually the stability management that tries to bring it all back under control when the driver gets it all wrong.

Just to add to the conversation, torque vectoring literally increases the car's capabilities. Stability control, even a fantastic stability control like PTM on the Corvette and the newest generation on the ZL1 which is almost universally considered the best out there, does not increase any of the car's limits. It just tries to keep drivers from getting in over their heads and to make it easier for less experiences drivers to extract more performance than they would be able to on their own.

Mike in CA

Agree completely. Far from interfering with the driver's ability to take control of the car, it expands the envelope of what's possible, just like a LSD, grippier tires, or any number of other ways of increasing performance.