on the way back from work this evening, I coasted into a freeway downhill ramp, probably a little over 100MPH and as I went through the left hander the psm activated maybe half a dozen times and as a result the car was a little unsettled. My thought were this car doesn't handle worth nothing. I have gone through this corner many many times, on 1000cc superbikes and an evo 9 MR and so eventhough it isn't the smoothest pavement wise, and I expect coasting at 100mph is not the best way to go through a corner. The car did something similar in a slow 180 degrees hairpin at maybe 30mph a couple of days ago, activating the psm. To me there was no need for psm activation. Now I am new to P cars. Any feed back would be great.

 

I had weird PSM behavior prior to swapping out a bent toe arm on the rear. It was causing one of the wheels to angle out a couple degrees. Since that, I have not had odd PSM behavior.

 

I also think the front shocks on the car are absolutely shot. Even if I sit on the fender there is no movement. Whenever I hit a medium size road imperfection a massive thump reverberates through the chassis. It feels as if the front shocks have no bump stops.

 

are the tires new? When I bought my car the PSM would trip out, new tires have a coating on them that makes them slick and this trips out the PSM till this wears off.

 

PSM can be very intrusive. It got even more intrusive with suspension upgrades. All the electronic handling gizmos seem to be turned for a totally stock car. The ABS goes off also goes off more often with 19" wider rubber and a stiffer suspension. It seems more about saving peeps that get in over their head (outa skill, outa brakes and outa luck) than a performance enhancement. It's a major PCNA cover their *** programming much like AWD. It saves you from lift thottle end swapping by not letting the back end step out in the first place. When i first got the car I left it on (per the admonishments in the user manual), but 9 times out of 10 it jumped in too early. It's does feel very weird having just one brake caliper being applied. Since my 996TT is not a daily driver, I've resorted to turning it off and paying attention to the car and it's handling. No phone, no music, no passengers, a/c off, to hear as well as feels what's going on.

 

+1 on all counts...

 

I'd have the car checked. If it's on stock suspension, you can get some interference from PSM, and if there's an issue with a swaybar endlink or a bad shock, you'll get even worse interference. The system is based on angles and attitudes and if the suspension is reading out of spec, the computer is doing its job. That said, I have it on at 180mph when I'm on track and it doesn't interfere in my lapping on roadcourses. With an aftermarket suspension, corner balance and the right alignment, this car will impress you way beyond anything you've ever owned... Mine does every time I drive it.

Mike

 

What are the tire sizes at each corner?

 

My PSM would never have interfered under those circumstances. Something doesn't sound right...

 

Mine has a well-dialed-in upgraded suspension, and well-matched tire
diameters, and I do have occasional bouts of exactly the same thing
where PSM will put a needless momentary tap on one corner's brake
in some completely pedestrian speeds in some corners if I'm off-throttle.
Mine is a very early 996tt. I heard that there is an upgraded rate-of-turn
sensor and perhaps one other sensor available for my car. If I were
off-throttle more often, I'd probably do this! (actually, if I get around
to pricing the job I may do it).

 

The car is on stock sized tires, PS2s and is an early 2001. The car is now back to stock right height. 26" plus or minus 1/2" measured from ground to the lower part of the wheel well. The car used to be lowered but I had it raised to keep it from scrapping in and out of the garage. The alignment was also adjusted. This morning I drove in with PSM off but didn't really get a traffic free shot at a few corners, but it seems to stick just fine. I'll try again this evening on the freeway connector, but I'll keep the throttle breathed. It is a technique that works very well on motorcycles to keep you from overloading the front tire while cornering. I suspect the front shocks may not be all that they need to be, since I can't seem to move the front of the car when I push on it. It maybe that is the way 996 Ts with aftermarket non adjustable shocks, TechArt/Bilstein 2002 vintage, are, but in my experience a properly working suspension is preferable to one that is too stiff. Then again the load on car capable of 190mph may dictate such a stiff set up.

 

I've read that whenever any suspension work is done, the steering sensor needs to be re-calibrated with the Porsche computer tools such as PIWIS. If this hasn't been done, this could be the cause for the car acting as it is.

 

That sounds plausible to me as my car has been ultra sensitive since my PSS9 install.

 

the only time my psm goes off is when its spinning all 4 tires lol

 

When I completely upgraded my suspension, my tech reset the steering sensor and I have not had any PSM problems. At the track I occasionally feel it cut power very briefly on a particular turn exit that is bumpy and high speed, otherwise it doesn't intrude. I leave it on as a safety valve because I don't want to meet Mr. Tirewall.