ABS/TC? Benefit or nanny?

[trygve]

For the Spec car years -- '97 to '99 -- I think there is only one optional thing on the car in this regard: "Traction Control". ABS is standard and you can't tamper with it for Spec although I suppose you could pull the fuse. I am glad to have it.

The TC option has two features:
- "ASR" (Anti Slip Regulator) - There is a dashboard switch to turn it off, and you really must turn it off for the track. (Unless it's wet!) ASR cuts the throttle when it detects rear wheel spin. You will get some small amount of "rear wheel spin" coming out of some corners -- that's desirable -- and it can be enough for ASR to complain about but you do not want ASR kicking in when that happens. ASR feels like the car is bogging down in that kind of full power sweeping corner exit.
- "ABD" (Active Brake Differential) - This cannot be turned off. However, it only operates at speeds under 55MPH so it's not relevant in fast corners, only the tightest/slowest ones. ABD detects left/right excess speed differential in the rear wheels and applies the brake to the inside wheel so that the outside wheel gets more power applied. This would seem to be activated when the inside rear wheel starts to lift off the ground and lose traction (maybe if you hop a curb too hard?). I have never really noticed any effect from this, although at Turn 11 at Sonoma if I hit the inside paint too much it's bumpy and I get something like "wheel hop", and I wonder if it's ABD rather than bad pavement. I think some people have talked about it causing rear brake pad wear (but I think that discussion was not about the Boxster).

I think TC is a fine option to have (ASR seems like a good thing for rain racing, and ABD is pretty much a non-event).

[ammonman]

Thanks again for the info. That is exactly what I was looking for.

Mike

[BYprodriver]

PSM prevents oversteering which is the funnest part of autoX to me & that's why I wanted my car without it. You can turn it off by the switch on the dash but, touching the brake pedal reactivates PCM. IMO TC is only usefull for winter driving. In Spec racing you don't want anything cutting back your rpm's.

[stephen wilson]

On my '06 , nothing re-activates when you hit the brakes. PCM ?

[MaxD]

Actually TC just plain sucks. In winter driving you can get stuck because you can't apply proper throttle when you need to. In A/X or track days it's definitely a no fun option.