Shiaohoo

I recently attended a track day with my '08 E63 and encountered a weird brake issue. I was on a wet track and one of the turns was down a hill. I braked coming down towards the turn and ABS kicked in. I slowed enough to take the turn so I left off on the brake. For some reason ABS stayed on even after I let off the brake pedal. It forced me to slow to 5 mph before it stop. Caused a traffic jam. My guess is even after I let off of the brake the ECU still detected tires were slipping? It was a bit unnerving and concerning that something is wrong. Any thoughts if this is normal or any experience with this?

u001elg

The ABS will not continue with the brake released... it will happily let you drift into a wall or other obstacle. The traction control is a whole other matter.


My best guess is that you decelerated hard and continued into the turn; the traction control saw the change in yaw, steering angle and differing individual wheel speeds and decided to brake and control of the vehicle until it was completely in control. Very useful on the street, not so much so on the track.


I have taken to turning off the traction control when ever at the track or drags (even though the drag times are about the same I like the visceral feel of controlling traction/or lack there of myself).


If you want to fling the car hard around a wet track the traction control may keep you from putting it into a wall, but it also won't let you drift around corners, control direction with the throttle or anything else fun.


So, in a nutshell, my belief is this is normal - try it with the traction control off.

Shiaohoo

Ah ok, I see what you're saying. I guess I meant traction control and not ABS. I'll try without traction control next time and see.