[Pcormier66]

Originally Posted by cdb95z28

Here's a good read on transfer layer:

https://centricparts.com/getmedia/bd...c-8-2018_1.pdf

Great read. Myth debunked.

[ICTsccaCamaro]

I was too lazy to pull the wheels off but this is at least shot through the spokes of both front wheels

[Pcormier66]

Textbook pad deposits.

[oneplustwo]

I had a similar shuddering/vibration. I used the coarse hone on my rotors and also switched to Raybestos ST43 pads. Vibration gone!

[ICTsccaCamaro]

Nice! Thanks guys, I ordered the coarse dingle ball hone linked above and will hit the rotors when I get the car up on the lift for this seasons pre-track fluid changes and alignment.

[Rams01]

Originally Posted by ICTsccaCamaro

Nice! Thanks guys, I ordered the coarse dingle ball hone linked above and will hit the rotors when I get the car up on the lift for this seasons pre-track fluid changes and alignment.

Let me know how it goes. I've been having the same issue ever since my last track outing with new factory pads.. Contemplating buying race pads and just sheering off the layer of deposit as suggested in here

[ICTsccaCamaro]

Got the hone yesterday, now to get the 1in of snow and ice off the roads. Also just so it is known I am running factory pads still for future information

[ICTsccaCamaro]

Follow up on the brake hone, I honed the crap out of both front rotors and reinstalled and still had a massive vibration, said screw it and pulled them off again and put them on the brake lathe at work and found the right rotor was pretty badly wrapped, but oddly enough the left rotor was still very true.
I went ahead and turned both rotors and measured and was still a good amount above min. thickness, so I used the brake hone to put and nice non-directional finish on them and reinstalled.
Nice and smooth braking now, we will see how they hold up to this track and autocross season, the tow truck got sold and the new ordered truck isn't here yet so it maybe a few months before it hits the any more events.

[cirpower]

You obviously need different pads for what you are doing. Had the same experience, once I drove the car faster, the brakes were giving up.

I put on a set of Hawk DTC-70s all around with titanium shims and the issue was sorted out. Also enjoyed the bite these pads had very much.

As I am relocating countries I am selling my pad set, they are around 80% and I sell them including the titanium shims which protect your brake calipers and keep the temperature out of the brake fluid.

I also happen to have a set of Kevlar brake lines for a killer setup, those are unused, I never got to fit them.

Send me a PN if you are interested, I am in Overland Park KS.

[Pcormier66]

I just got this article on brake vibration from Grassroots. It's a long read but very informative. I pulled these two paragraphs out.

https://grassrootsmotorsports.com/ar...tomation+Email


In nearly every single case, warped rotors are not physically warped at all. The common misconception is that the rotors get hot enough to distort and then, upon cooling, end up looking like a pretzel. Contrary to popular belief, rotors simply do not warp in this fashion.

The vibration that is felt in the steering wheel and floorboard is almost always caused by rotor thickness variation, also known as TV, and the physical pulsing in the brake pedal is nearly always a direct result of the caliper piston extending and retracting as it tries to follow a rotor of varying surface thickness.

[Og Neon]

Like others have said running some aggressive track pads with lathe the old material off and give you a fresh surface. I used St43 to do that and it was like having a brand new rotor again.

[ICTsccaCamaro]

Originally Posted by Og Neon

Like others have said running some aggressive track pads with lathe the old material off and give you a fresh surface. I used St43 to do that and it was like having a brand new rotor again.

My issue was unfortunately a wrapped rotor, not just pad deposits.

[Gunkk]

Interesting. Haven't seen a lot of posts with warped rotors. How many thou of runout was there on the bad one?

Glad you got it sorted.

[Norm Peterson]

Originally Posted by ICTsccaCamaro

My issue was unfortunately a wrapped rotor, not just pad deposits.

Are you completely sure it was warpage and not a case of hot spots in the rotor getting hot enough to harden (which makes those spots wear more slowly than the non-hardened regions around them)?

If it is a hardened hot spot issue, you'd have had a little difficulty getting a uniform cut and the problem is pretty much guaranteed to return - and not because you've machined material off of the rotor.


Norm