I have searched the forums & found nothing so I wanted to throw this out & see if anyone has any ideas. I have 19' HRE wheels with 315's in the back & 235's in the front. The car is lowered on H&R springs & has had 2 allignments from different shops. The car feels like it follows every little rut in the road & at high speeds it feels light in the front & feels dangerous. But if I turn the PSM off it stops following the ruts & feels more solid & feels heavier in the front & how I would expect this car to feel. Any ideas on what might be wrong?

 

Ask your alignment guys if they re-calibrated the steering sensor after they did the change. This is supposed to be done after any suspension or alignment work. PIWIS or similar Porsche computer tools are needed.

Following road groves can also be from front toe out. More neutral steering comes with very small front toe in.

 

Same type of tyre & wear pretty even? what tire pressures are you running?

 

my car has same wheel size and I noticed my car was finding all the grooves in the road also... I added some air to the tires and it helped out alot... mine was the same with psm on or off..