speedread

What happens on a 996 with the PSM off? I never see the light come on anymore at the track when I slide or drift with it turned on. I guess I'm doing those things smoothly enough that it doesn't kick in. (Or should I be sliding even more?) I drive my 996 in the winter and the PSM comes on a lot with snow, so I definately notice it, and feel kick in. When I've discussed this before with others, they speculated that I just don't notice the light, but as I said, I notice it easily with snow driving, as well as the feel. What I want to know is, if I turn the PSM off, will it stay off if I start to spin out, or will it kick in to "save me", even though it's been turned off? Will it be better to keep it on no matter how fast I get, or will it be better for the PSM to be off at the track? Does anyone KNOW the answer? Thanks.

DrJupeman

There have been lots of threads re: PSM here in the past. In short, if you turn PSM off, it will stay off until you hit the brake. Thus, if you start to spin out and you do not hit the brake, the car will happily flop about.

I always ran with PSM off on the track in my '01 Boxster S...

TD in DC

Actually, if you turn PSM off, it will stay off unless you (1) exceed a slip angle of 7 percent AND (2) hit the brakes. The engineers apparently made this decision under the assumption that, under most circumstances, hitting the brakes when you are really rotating the car means that you are trying to regather a car that is out of control. Under most circumstances, this is probably right. On the track, it can interfere with trail braking, where you sometimes want to use braking to rotate the car well beyond 7. . .

If you turn PSM off, you can brake so long as you are not sliding the car and the PSM will stay off.

If I were you, I would leave PSM on at the track unless it is holding you back, in which case I think I would disable PSM altogether rather than just shutting it off.

In my experience, there are two types of PSM activations: (1) the type where you screw something up and PSM intervenes to save your biscuits; (2) the type where the intervention is nearly imperceptible (e.g., perceptible only due to the lightly flickering PSM light) and seems to be created by "unusual" road/traction conditions (e.g., madness at mid-ohio).

Under the first scenario, there is not too much harm in letting the car prevent you from spinning (unless you are trying to practice your ability to save a car from an impending major incident), because you KNOW PSM saved you so you don't need an off track excursion to pound this lesson home. If you are a good enough driver that you don't need PSM, it will make absolutely no difference whatsoever whether you leave it on or off, so why not leave it on since it is a form of insurance for which you have already fully paid.

Under the second scenario, the car isn't actively intervening and there isn't really much you can do to prevent the flickering from occuring. At the few places this occassionally occured to me, I would play around with driving different lines/smoother, and it really didn't seem to make a difference. That said, since the car didn't really actively intervene, it didn't hold me back much either.

Since the PSM will come back on anyway if you are trailbraking, I personally can't see any reason to turn the PSM off on the track, unless you actually disable it so that it cannot come back on as designed.

Just my two cents.

Bob Rouleau

TD - I agree. Leave PSM on. If it intervenes, learn to drive more smoothly. The only time I have found PSM intrusive is on a car with R compound tires trail braking into a tight corner. Yaw-control (one of the PSM components) will kick your foot off the brake pedal forcefully. Yaw control cannot be turned off, it is indpendent of the PSM on-off switch.

Regards,

ZBlue996Kam

I agree with Todd. Keep it on if it does not slow you down.

I've been driving my 2000 996 C2 on the track since 700 miles on the clock. It has never slow me down. I tried to turn it off on track and I don't see any difference in terms of lap time.

I think you might get worse lap time with it off and slide a lot through corners. Sometimes sliding the car around the track make you feel that you're driving faster but most of the time your lap time suffers when you're sliding too much.

My $0.02

TREMPER

If you are smooth, you will never realize that the PSM is still on...

TD in DC

exactly . . . and if you are not smooth, you might end up being very glad that it was still on.

mitch236

The only observation I have is this. I don't have PSM (thank goodness it was an option) and my friend does. When it is on, he is not as fast coming out of the safety pin at Sebring because it is a very slow turn and losing some grip is part of going fast there. Other than that one turn, PSM doesn't seem to affect him, and he is a very good driver and trail brakes quite heavily (as one needs to in a 996).

speedread

Thanks for the responses. So far I slowly but surely keep getting faster, and the light no longer comes on, (except as I said, in the snow).