froggy47

I'll start a new thread on this, reference to how soft & long pedal my brakes felt after DE. The pads are oem c5z, fluid Wilwood 570, brembo blank rotors.

Took apart & I think they are glazed, please comment. 50% left so I took a coarse file & roughed up the glaze on the fronts, the rears I removed the glaze with sandpaper.

Think this will work once they bed in?

Feel better so far but not bedded yet.

What causes glaze? Should I go to a more track oriented pad next time? More than one forum member has said that oem c5z pads work for DE. They did work all day long, but then turned mushy on the street.

I have not had this issue with autox & HP+ pads, ever.

TIA

Rears with glaze?



Pad taper fronts, maybe 1 to 2 mm each end. You really can't see it in the picture. It's minimal.



Fronts, left is "deglazed" right as found after DE & drive home.



Rotor seems to have more evidence of "use" on the outer 50% of rotor, I took temps and the rotor was about 50 to 75 deg f. hotter on the outer 50% (as soon as I pitted & jumped out, but after a cool down lap. This seem ok/normal?



BTW I flipped the pads & and sanded the rotors a bit, the rotors did not show any wear (no lip).

AU N EGL

Glazing is from overheating the pads. That glaze is from the brake pad materal melting

YES either go with a race pad or slow down and that wont happen, will it?

Kubs

Yes I would switch to a track compound. OEM pads are terrible for DEs. You can go with an intermediate like a Hawk HT-10 or similar. There are pads that can take heat and still be easy on rotor wear.

BEZ06

Here's a quote from a StopTech technical bulletin. It's talking about removing uneven pad deposits from rotors:

I don't have any experience with this, but you might want to be careful with regular sand paper if it really will "make the condition worse".

YMMV,

Bob

Bill Dearborn

Drive around town with a set of Hawk Blues on and the pad deposits will be completely ground off the rotors.

Bill

froggy47

I was thinking about just putting the hp+ back on & doing the stoptech procedure on the rotors.

OEM pads maybe good enough for novice group DE day, but not much beyond that.

I don't really care much about rotor wear as the replacement stock ones are very reasonable.

What is the next step up in race pads (HAWK) after HP+ ??

froggy47

I'll get some garnet paper.

Thanks.

AU N EGL

Some spay brake cleaner on the rotors and a rag will get the brake pad deposit off the rotors

froggy47

I'll give them a scrub with garnet & brake cleaner & put hp+ back on for next autox.

These oem don't have much initial bite & I kinda got to likeing that with the hp+

c4cruiser

I think that OEM Z06 pads are pretty close to the Hawk HPS pad in terms of stopping power/use. The HP+ will work better and is a good entry-level pad for HPDE/track days. THE HP+ will need a little heat in them to start.

HP pads do need bedding when new That transfers some pad material to the rotor. There should be instructions included in the box on how to do that. If the rotors are not new, then they should be lightly turned or use garnet paper with a block. If they are not bedded in initially, it's possible to get some glaze on the pads.

froggy47

It appears HP Black is next higher performance then HP Blue.

Yes?

Zenak

if you get into the ABS too much that may happen more as well :-( Total lock up = bad

froggy47

Are you saying if the pad is too agressive & tire not grippy = too much abs?

J Ritt

Whew...you did a number on those rotors! You took the pads over their max operating temperature, and now you have uneven deposits on your rotors. Once the pad exceeds the temp for which it was designed, it starts to break down, melt, break apart, etc. That's what happened here. It has nothing to do with ABS.
Please check out this article I recently wrote. It explains in the first paragraph why you shouldn't use factory pads for track days. You are exactly the reason I wrote this article...just wish you had seen it sooner! http://www.essexparts.com/learning-c...ose-brake-pads

The arrows in the pic show the little splotches of pad material. If you don't remove them, every time you heat up your brakes, more pad material will stick on those high spots. Try the garnet paper route, but the Hawk Blue solution is probably your best bet at this point. Running an aggressive race pad cold will grind/scrub the existing pad material off of the rotor.


When you bed-in rotors, you want a nice even layer of pad material. To do this, you have to do it in a gradual manner while bringing the pads slowly up to the proper temperature. You can't just go out and hammer them on the track.
I just bed-in the rotor below on my car. Below are before and after photos of my right front rotor. The pad material is the blue/grey colored material distributed around the rotor. Notice that there aren't any splotches or globs of pad material...just even distribution. That's what you're going for. If you have splotches or pockets of pad material, it's going to create vibrations and high spots.





The HP+ don't have as much friction as the Hawk Blue's, so it would be tougher to remove the pad deposits with them while driving them cold. Hawk Blue will get the job done quickly. If you want to stick with Hawk's for track duty, try the DTC-70 compound. They are easier on your rotors than the Hawk Blues, and I believe they are better suited to a heavy, fast car like ours.

Hopefully that helps. Please read my article...I think it will help you wrap your head around this issue much better. Feel free to email me if you have further questions: jeff.ritter@essexparts.com

AU N EGL

in other words TOSS THOSE used HP+ pads

froggy47

The pads that deposited were z06 oem's. I never had deposits with hp+ in 7 years/2 vettes.

froggy47

Thanks for taking the time to answer my post, I just got some BAD ADVICE that oem pads were capable for a DE day. The rotors were new. I will try garnet first as it's less costly then buying Hawk blue to use as sandpaper. I read your article, wish I HAD read it earlier. I don't have ANY judder or vibration, so I think I can salvage these rotors.

I sort of intentionally went with the oem pads as a "safety factor" thinking that if I felt some braking "limitations" I would not push any harder on course. It worked as I drove very clean/smooth all day, passing cars in my (intermediate) group & never got challenged. This was probably not a smart plan but ya live & learn.

Very nice web site & company, please post more on the forum as your knowledge is much appreciated.

Z06Fix

HP+'s are a step up from the factory C5Z pads.

Seem to take the heat better and have quite a bit higher initial bite

AU N EGL

Funny never had a set of HP+s make it though one weekend. or HPS make it though one day at the track

Z06Fix

I got 2 weekend out of a set of HP+s. But I was being very easy on the brakes. Driving normally I doubt I could get a set to last more than a week either.

I would't drive the HPS's on the track at all. I can get them to fade on an autox course