I drive an 08 C4S (tiptronic). Love it.

I notice a grinding sensation as I press on the brake pedal - the feel is almost like metal on metal - in the following situations:

1. When I drive hard and I'm cornering (applying the brakes)

2. When the road is uneven and I'm turning at low speeds - for example going down a poorly made driveway (applying the brakes)

Is this PSM / traction control kicking in? Any feedback very much appreciated.

 

Sounds like it. Next time it happens, take a look at your instrument cluster, and see if the wee light is blinking. Low speed + turning is the clue. At low speed, you're never going to lose control of the car and spin out, *but* the speed differential between outside and inside wheels is quite high. PSM is usually triggered by discrepancies in wheel speed.

 

In 996 iteration, the lights don't always come on.

 

But the grinding noise/feel is part of PSM kicking in then? Just feels a bit jarring. Thanks for the feedback.

 

... are you crazy driving your car so hard that PSM has to kick in????

 

Just when applying the brakes lee? never off the brake?

 

Yep, that's exactly what it feels like. Just like when the ABS kicks in (it's the same brake pulsation).

 

This is more a technique thing. The rear weight bias of a 911 means that a little trail-braking is often useful to help tuck the nose in, and dial out understeer on turn-in. Too much, and the back end gets light, and it can easily turn into a snap oversteer, which is very hard to get back. It sounds like that's what's happening, which means you're driving it wrong. Brake sooner, turn in more smoothly, and you can get back on the power more early. The 911 mantra is 'slow in, fast out'.