kermooni

I am switching to slicks for my last three HPDE weekends later this summer / fall. I am planning on going with XP10 F / XP8 R.

What rotros should I use (with OEM brakes)? Should I freeze them?

davidfarmer

The OEM rotors are probably the best quality around, but the most popular option is to convert the brackets to non-Z51 configuration and use the cheaper c5/c6 rotors.

If by "freeze" you mean stick them in the freezer, that would be a waste of time. If you mean have them cryo treated, I think you'll find the money is not well spent. While it can extend life, it's only justifiable on high dollar items, not inexpensive rotors like the corvette pieces.

L98Terror

kermooni

I do mean Cryo treatment ... I am not a fan of cross-drilled rotors. I should also mention that my front brake air ducts are in place bringing in plenty of air (I believe). I am also not going away from the Z51 calipers. They are much better than the older kind or the Z06.

All of this said, what rotors should I use?

EvilBoffin

Your calipers are not specific to the Z51 package, so you don't need to go away from the Z51 calipers to use the non-cross drilled, C5/base C6 rotors that David recommended.

You would just need to buy a set of C5 'abutment brackets' and swap them out when you change to the cheap rotors for HPDE use. A set of four brackets is about $120 if bought new, but you can find used sets for sale in the 'C5 Parts for Sale' forum pretty regularly.

You'll end up with a dedicated, complete 'kit' of rotors, pads and brackets for DE's, while keeping your cross-drilled Z51 setup dedicated to street use. The ONLY item that wouldn't get swapped back n' forth would be the calipers themselves.

Aftermarket pad fitments are the same for all C5's, Z51 and base C6's, too. The FMSI (brake industry standard) pad numbers for our cars are :
- D731 for front pads
- D732 for rear pads

As for rotors - my recommendation is to stay away from Centric. I tried them because they're about the only cheap Z51-sized rotor available, and they didn't last long on-track at VIR. They ARE cross-drilled, even though the online pictures of them show that they are plain.

See this thread for other (pricier) alternatives like DBA & Coleman Racing:

http://forums.corvetteforum.com/show....php?t=2060368

AU N EGL

No cryo rotors. they crack just as fast as drilled and slotted

The C6 calipers are identical to the C5 calipers, just the lettering is different

Cyrus, the stock caliper mounting brakets, and the stock C5 / C6 rotors or the NAPA rotors

86700
86701
86702
86703

or rockauto.com rotors

56700
56701
56702
56703

are the rotors of choice

WNeal

Huge cost savings and they stop just as good

kermooni

Thanks to all the guys above for educating me. I had heard (read in this forum) that:
1. NAPA rotors are junk. They crack very quickly
2. Z51 calipers are made tougher than C5/C6 ones (they are made of thiker material) which stops the slanting the pads.
Any truth to the above?

Do any of you guys disagree with use of XP10/XP8? ANy issues with using them in combination with the recommendations above?

I realize I am being very picky. I am sure you understand it is because failure is simply not an option.

Thanks.

AU N EGL

false and false

NoOne

The C6/GTO caliper was SUPPOSED to be made a bit stronger on the bridge area than the C5 caliper...but they still taper just as bad.

I pulled pads off my buddies GTO with 7K of mild driving and they had bad taper.

0Vector Vette

1. Napa rotors are cheap chinese made rotors. They are fine for driving around on the street. They do not hold up to the abuse tracking/racing puts on them.

2. C6 and C6 Z51 calipers are the exact same caliper. The pad taper is not caused by the caliper flexing, it is due to both pistons being the same size. The leading pad will always take more abuse than the trailing one. That is why real racing calipers have stagered piston sizes. The AP Racing 6 piston caliper I run on the front of my car has 3 differant sized pistons and the pads wear is even.

3. I do have a replacement racing rotor for the Z51. It is a Coleman Racing rotor made to our specs with an aluminum hat we machine ourselves. It has gas relief slots, no drilled holes, is vented correctly, American made, and weighs about 7 pounds less then the stock one. It isn't cheap though at $373.50 each and replacement rings are $196 each.

PM me if interested
Robert

NoOne

Matching piston size may be part of it but the biggest part is from the flex in the bridge.

Thats straight from a former PBR supervisor who worked on the C5 program with GM. When he left PBR he joined the company I work for and was in my department for a few years.

FaSStC5

so whats the difference between a regular c6 calliper and a z51 calliper?

Rob Willis

Nothing.

FaSStC5

so its the same identical caliper?

robvuk

Only the rotor is different diameter along with the bracket to mount the caliper.

FaSStC5

so the c5 and the c6 calliper is the same also?

kermooni

The Q still remains:

Are Z51 Rotors thicker than standard C6 ones?

0Vector Vette

No, they are both 1.25" thick.

EvilBoffin

Vector Vette / Robert -

Not trying to steal kermooni's thread, but this issue with track rotors just never seems to get resolved.

I referenced your post about the Coleman's in that other thread because I agree with your points about the risks of running crap rotors. It's really great that you offer a 'real' racing rotor upgrade - especially in Z51 sizes. But it's still tough to know how to justify $750 for 'just' a pair of rotors.

So - A few questions for you :

1 - You say the Coleman's last a lot longer compared to NAPA's or OEM cross-drilled Z51's. OK, how long can we expect? One HPDE weekend more, FIVE times longer, a whole season of DE's?

2 - Would I need to buy TWO complete sets of rings AND hats and take the whole extra set with me as a backup? Or can new rings be realistically swapped onto the hats QUICKLY enough between sessions to allow enough time for them to cool off, switch the rings and reinstall without sacrificing a session of track time?

3 - What REAR rotors are appropriate to use as a companion to your Coleman fronts?

4 - I know you sell Cobalt pads, but would these rotors work well with Wilwood H's or Carbotech XP12's? I use the Wilwood's right now, BTW.

Thanks for your time and advise,
Robert