here is steering wheel sensor alignment link

http://www.renntrack.com/forums/show...-on-durametric

 

Here is the kicker "the yaw sensor, the lateral acceleration sensors" These are calibrated to the P-Zero street tire. With stickies the PSM takes all the fun out of playing on the track. Thanks to a post here I was shown how to unplug the charge pump for playing on the track. Your experiences may differ...

 

After installing a more aggressive suspension, I also noticed both the ABS and PSM going off alot more. However since I'm pushing the car harder I'm not surprised. I'll admit it's a bit intrusive, but has gotten me out of some trouble a few times. I also just finish running a SLS at Laguna with ESP (MBZ version of PSM). Admittedly this is a more advanced system coupled to the active suspension. My instructor told me on several turns I would have been in the weeds if the ESP hadn't kicked in. Basically these stability management systems make you better driver than you really are.

What's the difference between a spin and a crash.......the sound at the end.

 

Yeah nice article....
I do not believe in the 996 PSM... It does work at times but at many other times it goes off the deep end. The worst moments are when it chops the throttle. Porsche fixed most of the issues with PSM in the 997.

For basic driving it does OK, push your car or modify the suspension and you have a nightmare on your hands, add in some rough less than ideal road conditions and you have a disaster waiting to happen if you drive hard.
Now I caveat the above with needing to have some driving ability and sensibility to know what the car is capable of and what you are capable of.
The laws of physics are irrefutable and unforgiving. Something as potent as a 996 is akin to a loaded weapon; you either know how to wield the weapon or it will hurt you because you cannot rely on its driver aids as they are very flawed. There are so many other cars out there that actually integrate these driver aids much more successfully; usually they are newer models then the 996.

 

I've been running r888's on the track for four years now without any PSM issues at all. Recently upgraded to TPC sway bar and toe link suspension and now it's even tighter and more responsive. Only problem I had was a sensor became unplugged when I pulled off my street HREs w/ Hankooks to put on the Toyos. Not sure why the harsh review on the factory system. Handles turns quite well and doesn't interfere at all with the twists for me. Even braking from 145+ down to 25 without event. I love it.

 

I've run my car with PSM on the track and found it fairly seamless and unobtrusive if you are a smooth driver. It made the car easy to drive relatively fast but I would cook the rear brakes from the PSM pulsing the rears brakes to keep the back end in check. PSM on the track makes a mediocre driver feel like they are a better driver because it masks a lot of their mistakes. PSM did slow me down a bit. These are my findings running at HPR:

1: AWD with PSM ON: 2:07.33
2: AWD with PSM OFF: 2:06.52
3: AWD with LSD and PSM OFF: 2:05.12
4: AWD with LSD and PSM disabled: 2:04.56
5: RWD with LSD and PSM disabled: 2:02:48

Ultimately I prefer the car with set up #5 above because it makes it a drivers car and you can ultimately extract the most performance from it. You really have to be on your toes and pay attention when driving it at the limit but it is a ton of fun compared to the numbed down PSM car. The trade off is the fact that the car will bite you if not careful and you cross that line. I don't care about PSM on the street because I just don't drive the car hard enough on the street that PSM would be a player. Just my $0.02. YMMV.

 

I hate cars with nannies...

 

I believe PSM helped save me from a potentially very serious accident when I in explicably put two wheels off and got sideways at 116 MPH on a narrow walled section a couple days ago at Laguna Seca. Yes, it's annoying when it consistently kicks in on certain turns, and a no brainer to deactivate on low speed autocross courses. But the margin of safety that it provides is well worth the compromise IMO. Me and my beautiful car are home safe, and the second or so a lap I lost when it wasn't saving my a$$ just doesn't seem that important by comparison.

 

This.

Unless you're getting paid enough money to compensate your losses, I don't seem it worth the risk. Everybody is different.

I know when I track, my car is my trophy that I take home. If I don't take it home, I lose.

 

Well said jasper

 

what sizes are your tires?`width etc?

 

The problem with PSM (even if turned off via the dash switch) at the track is that you will cook your rear brakes if you drive hard enough or trail brake at all. Your rear calipers will get hot enough to severely discolor or even melt the paint due to PSM constantly
jabbing the brakes.

 

Another point to be made here is that turning the PSM off on the dash only disables PSM, up until the point that you step on the brakes. Once you step on the brakes PSM is back on.

I track my car and it has been lowered to GT2 heights and I run 2.8 degrees of camber upfront. Prior to upgrading the suspension, PSM was fine on the track. Afterwards, it interferred far too much. I turned it off, but had some ugly PSM moments trail braking into turns, where PSM would stab the brakes and induce issues.

There is a thread here with a photo of the big plug under the master brake cylinder, but it is the one about the size of your thumb under the master brake cylinder -- when you unplug it, it will throw a warning on the dash that PSM has failed (you know you have the right one), and the light goes away when you plug it back in.

Once unplugged, I took 3 seconds off my lap limes with my new suspension.

 

Thanks for the wealth of info! When I get a chance, I'll try cleaning the sensor first and see if that makes any difference.

 

Definitely a good point but there is also the saying that "you shouln't track it if you can't afford to lose it"