Stability Control Coming on After Front Wheel and Rotor Change

[naikaidriver]

I was out at the track on Tuesday for the first time after going to a square, 20x10 wheel setup with 275/40 20s all around. I also upgraded my rotors to the slotted Brembos.

Since then the front of the car would just "feel" strange. Occasionally when cornering really hard, I could feel what can only be described as a drag on the outside, front tire. It would do this without the front losing grip and it felt really strange.

By my 4th lap, the smell was a dead giveaway. My front brakes were cooking. I am running on a new set up Hawk HP+ pads and I ran the same type of pad for hundreds of laps for the last two years and this has never happened.

To test my conclusion, I turned off the Stability Control completely and the issue went away along with the smell. I normally run the car in "Competition Mode".

Anyone else experience this on the track? Do you think my ABS just doesn't like my rotors or the wider, front tire? I would think that because it is the same diameter as the OEM front tire it shouldn't have been a problem.

Scott

[Norm Peterson]

I highly doubt that it's at the ABS level because the 275/40 is very close to the same diameter as your RS's OE 245/45 front tire. Different rotors should not matter because they're not going to cause unneeded braking.

Since it went away when you shut Stabilitrak completely off, I suspect that your new wheel & tire combination is a good bit less understeerish than the OE wheels and tires were, and that the ST is getting nervous before you are (braking the outside front is a typical stability control reaction to sensing oversteer or perhaps not enough understeer). It could also be a consequence of driving differently.


Norm

[naikaidriver]

Originally Posted by Norm Peterson

I highly doubt that it's at the ABS level because the 275/40 is very close to the same diameter as your RS's OE 245/45 front tire. Different rotors should not matter because they're not going to cause unneeded braking.

Since it went away when you shut Stabilitrak completely off, I suspect that your new wheel & tire combination is a good bit less understeerish than the OE wheels and tires were, and that the ST is getting nervous before you are (braking the outside front is a typical stability control reaction to sensing oversteer or perhaps not enough understeer). It could also be a consequence of driving differently.


Norm

This was my feeling as well. Thanks for chiming in Norm.

The car is cornering MUCH harder now after going to the 20x10, square setup. I recorded a high of 1.06g with my datalogger and I am now hitting .9 much more often than I used to.

Still I wish I could leave the Stabilitrac on though. I liked having that added insurance in the event I experience a momentary lapse of judgement on the track.

Scott

[CamaroFred]

From what I have read the ST uses the g-force detector to determine the direction the vehicle is turning and compares it to the steering angle. That is, if the vehicle is turning right and the steering is turned past a certain point to the left, StabiliTrac will begin applying the brakes on opposite corners to reduce the oversteer.
At least that's the only time I have ever felt it kick in. From my experience it allows a good amount of oversteer and kicking the ass out a bit while cornering will not invoke it. It takes a fairly large amount of countersteer.
Now I never noticed if the dash light blinks when it kicks in like the TC does. Didn't really have time to look at the dash.
That said, I have no clue what could be causing your issue.
BTW, I have 9s and 10s with 275s all around.