JScheier

Hmmm... just saw that someone set the TTA Track record in May... and it is slower than my (posted in the MPH thread) TTC time on street tires. Might have to go back just to reset the record

cloud9

Sounds like fun

CO_VaporGT_09

So true! Mustang weekend doesn't count for NASA!

cloud9

I hope be does some corner carving AND some wood carving. We need to fill in the Mustang end of that table at the Roundup!

MJockey

Good to know info on the DTC60s. Hawk Blues destroyed the finnish on my M3 rims.

kona302

Under the category of question I should know the answer to: Despite multiple calls to various places and too much time on this and other forums I don't know this. For ordering brake pads and replacement rotors for tracking my boss 302 are they the same size as on the GT500 or the gt with brembo package or are these one and the same?

Thanks for any help.

adam81

Yes the GT500, the brembo package, and the Boss brakes are the same.

Absent

Hey guys, anyone considered the Shelby rear brake upgrade.

http://www.shelbystore.com/product-p/z28-2262019.htm

5 DOT 0

I was told that adding larger rear brakes to the Boss is a waste of money. The Boss 302R runs stock rotors and calipers with race spec brake pads.

adam81

+1 with the 302r and 302s running a stock rear setup with upgraded pads. I was also told it is a waste of money as all the testing proved what is used works.

I do have to say that I would like a larger rear rotor just for looks. That little thing looks ridiculous back there...

5 DOT 0

Yep it does look pretty small especially compared to the large front rotors.

MJockey

Grand Am requires the 302R to run the stock size / type rear brake rotors and stock calipers. When I asked the Roush team why they didn't upgrade the rear brakes, he said they weren't allowed too.

5 DOT 0

But they're allowed to upgrade the front brakes? They run the Brembo Pro kit on the front.

MJockey

Yes they can upgrade the fronts but they are limited by the required wheel size.

CO_VaporGT_09

Ok, guys, looking for some help here -- revisiting a prior old post of mine in May.

I now have two sets of rotors with the weird pattern on them:











The last pic isn't in focus, but is meant to show that the dark areas correspond to the voids, the light areas to the pillar vanes.

The non-slotted rotors are standard Centric blanks, cheapo $35 ones. The slotted are the Roush Track Pack, which I believe are just the cryo-stop ones.
Other parts of the brakes: ducted 14" StopTech ST-40 fronts, heat shields removed in back, EBC BlueStuff pads all around for track use. Traction control always off, and minimal on-track ABS pulsation, if ever.

The slotted ones were after last year's events, and the first three of this year. The newer non-slotted ones are only three events this summer, so not as bad but showing the same pattern coming on.

Interestingly, similar pattern but not as severe on the backside, though worse w/ last years slotted rotors.







Now obviously I've got some nice pad patterns on the newer non-slotted rotors (sitting in hot pit at one point, when a yellow was thrown on track, no option but having the brake pedal down with hot pads/rotors). Would hopefully come off with a re-bed in process, though I have Hawk Blues to use to clean them if necessary.

The other issue is that the right rear inner pad is not making full contact, and the pads on that corner show mirror-image taper abnormalities, though longitudinal instead of radial.

I think that was related to not having the axle centered after I installed my Watts link, which I have somewhat solved now (but I do believe is the source of some incessant squeaking with suspension travel).

Any other ideas for me out there

Last time I asked, everyone was saying heat is the issue, either too much or too little, though most thought too much. Everyone also said the slotted rotors were done-for, though my standard straight edge calipers said one more mm before min thickness. The surfaces have typical spider cracking, but that's it. Some people felt this represented unequal pad deposition, others thought it was the variable heat/cooling of the vanes versus non-vaned areas causing metal discoloration.

Also interesting the pattern is the worse on the outer surface, which should be cooler than the inner disc, I'd think.

I am headed out to Hastings this coming weekend, so will be using the newer non-slotted rotors, though I do have some barely used ATE rear discs for the street, I could use if these non-slotted ones aren't safe.

Thanks!

06GT

The pattern is normal, just corresponds to the cooling vanes. Looks like you might have left your parking brake on after a session or two with one of those sets of rotors?

Can't help you with the pad taper bit.

5 DOT 0

Yep mine look pretty similar.

CO_VaporGT_09

Good to hear! That's the first anyone said "normal".

So what's the criteria (other than thickness) for replacing the rotors? Several people said the slotted ones were shot.

5 DOT 0

Are slotted or drilled rotors even necessary for tracking a car with modern brake pads?

06GT

Cracks extending from the OD of the rotor. Some heat checking/surface cracks are normal and can be ignored. If you have a crack at the edge of the rotor, it's time to replace it. Also if you have any serious grooving of the rotor faces, it could be time to replace. Some grooving is normal, but if you find any that are significantly deeper than the majority of what's on the face it could be time to swap out. This will be dependent on the type of pad compound you use. Harder compounds used in racing pads will act like a lathe on your rotors when not at operating temperature.

Totally worthless/for cosmetic effect only on most cars, and typically easily-affordable cross-drilled rotors will crack at the drill points. I've only seen OEMs like Porsche/Chevrolet/Brembo do it correctly. If you are interested in anything other than blanks I would suggest the slotted rotors--but blanks are more than sufficient.