ABS bake systems
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 44
Likes: 3
From: Florida
ABS bake systems
I was at Sebring Raceway doing a HPE Track Day. Does anyone know why my ABS came on in several turns but did not feel the vibration in my pedal?
thanks for the info
Greg
thanks for the info
Greg
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,629
ABS kicking in due to active handling? If yes, where you running in Comp mode, or all nannies on.
If all nannies on, quick way to have the car want to go straight during braking into the corner, instead of turning into the corner, from too high of G reading on the yaw sensor that will trip AH.
And when AH trips ABS, no pedal vibration. AH Kicks the ABS units on to straighten out what it sees as the car in too high of a G turn (keeping it going straight, of better yet, to get it back to front of the car forward), so off the track you go instead of turning into the corner.
If in comp mode, then need to check the steering wheel position sensor, and the Yaw/accelerator sensor to make sure they are not going south if you were still within the slightly increased G loading/rear end allow to step out slightly more comp mode will allow.
Myself, I run in all nannies off mode for track use (only ABS Brakes still on) since I pretty have the car skating at all times that would still have AH kicking in in comp mode, but better have the skill level before you temp this, since no nannies on means you screw the pooch and take the car past the edge at any time, nothing in play to save you as the car tries to kill you by swapping ends down the course.
If all nannies on, quick way to have the car want to go straight during braking into the corner, instead of turning into the corner, from too high of G reading on the yaw sensor that will trip AH.
And when AH trips ABS, no pedal vibration. AH Kicks the ABS units on to straighten out what it sees as the car in too high of a G turn (keeping it going straight, of better yet, to get it back to front of the car forward), so off the track you go instead of turning into the corner.
If in comp mode, then need to check the steering wheel position sensor, and the Yaw/accelerator sensor to make sure they are not going south if you were still within the slightly increased G loading/rear end allow to step out slightly more comp mode will allow.
Myself, I run in all nannies off mode for track use (only ABS Brakes still on) since I pretty have the car skating at all times that would still have AH kicking in in comp mode, but better have the skill level before you temp this, since no nannies on means you screw the pooch and take the car past the edge at any time, nothing in play to save you as the car tries to kill you by swapping ends down the course.
Thread Starter
Intermediate
Joined: Jun 2013
Posts: 44
Likes: 3
From: Florida
Thanks for the info. I run with all the nannies off. My car is basically a race car its not street legal. I have a complete racing suspension, JRI coil overs, delrin bushings, lager swaybars, hoosier tires, wilwood brakes, splitter and wing, ect. I'll check my wheel position sensor and the yaw to see if that was causing the problem.
Race Director
Joined: Dec 2013
Posts: 12,502
Likes: 3,629
Tech II, go to BCM or EBCM data, with motor running. Wheel straight should have the sensor at 0 volt, turn the wheel to left should have the voltage climbing in the negitive voltate, to the right off center, climbing in the positive voltage. So one wheel turn to left, then one wheel turn back from center again to the right, should have the same voltage, but just the difference of positive or negative voltage.
As for yaw sensor (its under the HVAC controller), tap to the right side, then jab to the left side, should be reading close to the same G reading both ways in Data. Front and back jabs as well.
