It's a VERY fine line. You have to have figure out exactly where the Yaw sensor, sterring angle and wheel sensors will let you "play". I had a lot of fun finding the right mix so that you could have some fun and still have the PSM on.

But I kinda thrive on trying to see what you can and can't do with the system simply because I have taught the course for so long. I also have access to the facilities to really experiment with it.

 

I am hesitant to turn PSM off on the street. It saved me once last week in unearthly braking to avoid a jerk who was waved blindly by another jerk in traffic across me @25-30 mph. Damned school bus driver waved a white Escalade to cross major traffic blindly! I don't know how I missed them! She just hunkered down and planted herself right there. No ABS pumping and no forward body roll. Just stopped.

We are going to get our first snow any time. When that happens in this little town of 230,000 there are going to be 200-400 or more accidents. That is one day smart people stay off the road regardless of what they drive and their skills.

I really love my car. I just wish she weren't so costly to maintain and repair.

 

I drive with it off when I want to have a little fun since it keeps the car in a lower gear and keeps the revs up around 3k. Picking the car up with all the mods tomorrow, so maybe that won't be necessary any more.

 

Cole,

It hasn't snowed at my house in 50 years, so I wouldn't be able to comment about traction control or anything else.

However, in the streets of Downtown LA I can guarantee turning PSM off starts me off in D1 at every stop, delays up shifts, and even blips the engine for me when downshifting from third to second. The engine functions much more aggressively, just like every modern Porsche I've owned with this feature. This equals better pedal response, and sportier driving, with no noticeable wheel slippage on dry pavement.

 

Med,
I am in the same place. In regular PSM on Mode it starts in second and is smoother, drives like my wifes Benz. Turn it off and it's a different car to the point where my wife does not appreciate me driving with me when I have my "happy" button off. Just yesterday, "please turn that damn thing off it's jerky and giving me a headache".

 

Mine will start in D1 with the PSM on. Just push the pedal down quickly and it jumps down to D1.


My upsifts with PSM ON are clear up at readline and it holds the gear all you want if you are in a corner.

It may really be driving style. YOU get more aggressive when you turn the PSM off. Try it all with the PSM on and I think you may be surprised. The more aggressive you are more often the more aggressive the throttle map in general.





FWIW,

I've autocrossed my CTT and tried both PSM off and on. The ONLY noticeable difference I have found is it not pulling throttle away from you when you get it sliding. The response of the throttle and shifts was the same with PSM on or off.

http://www.youtube.com/watch?v=bEyZu5WcupI

 

Just got mine on Saturday. Punching the "Sport" button makes a big difference in response, shifting, etc. Also starts in D1 that way.

 

This is an old but tremendously good article from a racer on PSM on and off. I do not know how to send hot links so you may have to fish for it but worth it.


http://www.deter.com/porsche/PSM.txt


Wonder what if any changes to PSM since introduction? Having run in the snow for 20 years in the mountains north of Montreal (1965-85) its good to now know in my head what was going on with my butt and car.

 

Very cool article.

Thanks!

 

Cool read!

 

Now that some with more knowledge than I are reading this article, a question arises. If PSM slightly brakes the inside rear wheel to help rotate the car faster through a corner, how is this functionality substantially different than the new porsche torque vectoring plus. Being slow in physics, these real world examples of what we actually experience in our cars is so helpful. thanks.

 

Did a bit more digging. In addition to the braking of the inside wheel similar to PSM, PTV brings a mechanical limited slip rear differential to the table. PSM focuses on the wheel with the least traction as in slipping (inside wheel) whereas PTV's diff can apportion more torque to the heavily weighted outside wheel thereby increasing rotational force.

Additionally, and back to the real subject of this thread, PTV is active even when PSM is turned off, as in real performance driving.

One last note, if PSM is off and you get in trouble, braking the vehcile tells it that you want more control so PSM kicks back in ( I think, confirmation?).

Like wOOt admitted so candidly in favoring PDCC and PTV, I have not yet driven a Cayenne so equipped. My CS is on the Aida somewhere between Nova Scotia and NY. Next stop Brunswick, Ga!

 

On the first generation Cayenne, which was the first Porsche PSM system, PSM does NOT kick back in! Once off, it's always off.

The first I heard of PSM kicking back on/in when it was off was on the CaymanS. However, I think the new Cayenne will come back on and I would like confirmation from a current owner about this.

 

nice thread