Warped Stoptech rotors. Part 2....

[GTS Dean]

Jim,

You treat your brakes the same way I do - allowing ample time to cool after hard use. This means keeping air moving through the wheelwells until the rotors are down from 1300F to around 400F before you park it. I've had the same set of STOCK Viper rotors (track only) on my GTS for 4 weekends of HEAVY usage and four sets of Brakeman #3 and #4 pads, WITHOUT turning them yet!

Observers at the end of the S/F straight in Corpus last weekend said my discs were glowing bright cherry red in broad daylight. I was outbraking nearly all of the Porshces in attendance at the PCA time trial and carrying a LOT more speed than they were.The outboard ends of my Porsche brake deflectors are melted, and it's now time for third set of ball joint boots. I'm running stock calipers, Ti pistons, Aeroquip lines, Porsche deflectors and AP600 brake fluid.

No warpage problems if you break new components in properly and treat them right when you get ready to come off the track. Don't ever set the parking brake in the pits with a hot car!

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[SoCal Rebell]

I posted earlier about my brand new front Stoptech rotors warping at Viperdays. Well the people at Stoptech have been very helpful and have been aggressivly persuing why this happened and we have figured it out. It was kinda my fault but also kinda their fault, what happened was in the box with the brakes was an old set of pad bed in instructions. Stoptech had thought the weeded out all the old instuctions but the box I got had them. The old instructions are not aggressive enough and although I followed them it was not enough. I would like to thank Stoptech for all their help in this matter, I am now more then satisfied with the system and highly recommend them. Their customer support is unmatched.

 

[Janni]

Maybe I am missing something here, but the rotor supplier is sending PAD bedding instructions? Should not that come from the pad supplier? I understand that the reason to bed most pads is that they outgas during the first few aggressive heat cycles and perhpas that is why they have included them with the rotors. However, if I remember correctly, Ron, you were using Brakeman #3 pads which are all "pre-baked" so that bedding is NOT required as they have completed all their outgassing in the oven. We've gone through TONS of sets of those pads - all without bedding and all without destroying any rotors. Or is this to heat cycle the rotors? I've bought other rotors that could be purchased already heat treated....

We previously had an issue with rotors being scored badly, but that was caused by too agressive a pad NOT getting hot enough and remaining in its abrasive stage, as opposed to its adhesive stage. That was a logical reason, I don't know if the above is...

Just curious - always in a quest for more brake component knowledge....

 

[jrkermode]

Bedding not only prepares the pad, but also prepares the rotor surface, by "cooking" on a thin film of pad material. So, including bedding instructions is not so strange.

 

[Jim Hodel]

I think that no matter what rotor seasoning and pad bedding procedures you use, that you will risk rotor warping if you do not allow a significant cool down period before parking the car. I have the same problem on my Z28 with 4 piston Alcons and single piece 13 inch rotors (and the Z28 doesn't have near the top speed of my Viper).

I need to drive a cool down lap and then drive around in the pits in order to cool off the rotors after running hard, or the rotors will warp. Even with the cool down, I eventually warp the rotors somewhat. I have tried turning the rotors, but they have a warp 'memory' so it always comes back.

I have the Stoptech big calipers and two piece rotors on my Viper and have not had a warping problem, but I only have one track day on this system and may not have been running hard enough to have a problem.

One other thing, is that I have heard that single piece rotors have a bigger warping problem the two piece rotors, but I don't know if that is true or just more 'lore'.

Jim