fmcokc

Hi All,

We are probably going to be taking a C6 Z06 (basically stock) on One Lap of America in 2013. One of the things that we have done a little work on is the brake setup. I have tried a couple of different pads with the stock rotors and Michelin Pilot Super Sport tires.

What I have found is that stock pads are barely up to the task of a few hot laps but are inconsistent and do not inspire confidence to go too deep. Cobalt XR2 pads have a very hard initial bite and ramp-up. It's very easy to get into the ABS with these on "street" tires and with the ramp-up characteristics, it's even harder to get them out of ABS.

Does anyone have any experience with "race" pads and street tires?

I am thinking about Cobalt XR3's or Carbotech XP10's but I want to get some feedback from people who have tried several of these before I go out and spend money on pads that won't work and someone has tried before.

bluemagoo

Carbotech XP10 front and XP8 rear

Andi

Your best option would be to convert to the ZR1/Z07 carbon ceramic brakes.

If that's not an option, go with the most aggressive, non-streetable, race pad you can find. On my previous Z06, I ran Carbotech XP20 fronts and XP16 rears. Great bite and great fade resistance.

Good luck! I hope to return to OLOA one day.

Andi

Adam@Amp'dAutosport.com

May I ask what pads you tried and what was your findings?

fmcokc

So far I have only tried the Cobalt XR2 pads both front and rear and the stock pads which are a Ferodo I believe.

Since we have to run a street tire and the tire of choice at the moment is the Michelin Super Sport that is what I have been running on.

The XR2 has an aggressive bite and ramps up quickly which can be a problem for a street tire. It does give a lot of confidence to me in the "feel" of the pedal.

I have had quite a bit of experience with Carbotech pads and in fact used them last year to win a national championship. In the Carbotech pads, we used XP8's and XP10's on our race car (not a vette) and I really liked the feel of the XP10's over the XP8's. The 8's felt more compressible and less linear than the 10's.

How would the characteristics of the XP10's compare to the XR2's in bite and ramp of the torque curve?

fmcokc

Why the differential?

If you run squared are you seeing rear lockup?

bluemagoo

My rationale: The rears don't do as much work and so don't get up to as high a temp as the fronts - thus rear pads that are designed to work in a slightly lower heat range. The ABS obviously prevents any lockup but braking seems better and more controlled if I can keep any of the wheels out of ABS.

With the different types of event incorporated into OLOA I would imagine you would need a pad that doesn't fade on a road course but gets up to temp quickly on an autocross or low-speed event.

I'm no expert and others may have additional feedback for you. Talk to Adam @ Carbotech about his recommendations for your specific application. Have fun with One Lap 2013 - sounds like an experience!

froggy47

Are you allowed pad changes for each venue?

Bill Dearborn

With the combination of events and running on street tires give the Cobalt CSR pads a shot. They do well on a road course like Watkins Glen, are great for autocrosses and can be driven between events. Not a pad to use on a DD but worked well for me. About the same price and performance as the Carbotech XP10/XP8 combo I used a couple of seasons ago but last longer. With either Cobalt, Carbotech, or Hawk pads make sure you bring plenty of front and rear rotors if you are going to do a lot of laps on road courses. I go through stock rear rotors in about the same amount of time as I do front rotors.

I have used Hawk HP+ pads quite a bit because the overall cost is cheaper but they don't stand up to the heat like the others. The DTC70 is probably too much pad. I have toyed around with the idea of buying 3 sets of Hawk DTC60s and running them front and rear.

Bill

Z06trackman

My track set-up for years was XP8s all around with street tires, including NT-05s, on both Mustang Cobra and C5Z. I was very happy with the performance, temp resistance, feel and especially rotor wear (like none). As for modulation, I have a witness who repeatedly saw me drive deep into turn one with smoke whisping from the front and rear tires while still turning (that was in the Cobra).

I have since moved to the XP10s only because I am running softer tires. Since a computer modulates the proportioning on C5+ Corvettes, you don't need to run a staggered setup.

fmcokc

Yes but you won't want to.

Spend all day at the track then drive 600 miles and get to bed at 2AM. Then get up at 6AM, get breakfast, get to the track, walk the track and do it all again for 7 days.

Plus space is at a premium since you carry everything you need for 8 days in your car.

fmcokc

I don't see the CSR pad on their website???

jaa1992

I put XP8 on all four corners of my daily driver six months ago. With the exception of the squealing on the street they are a great compromise for better than stock pad on the street and a useable track pad. ~4K lb Camaro v6 stock calipers.
Going from 118 (won't go no faster ) to 50 ish into 10A is very doable for a 20min session, need to modulate the brake a little to keep from locking up the 5000 treadware all season carp stock tires though

Lawdogg

In the One Lap, you only run 3 laps at a time and you won't have any real chance to get heat in the pads. You will also be on street tires that can be over powered by too much pad. I tracked street tires and Cobalt CSRs for three summers with my '07 Z06 and it was a great combo. Strong performance and easy on rotors. I also ran them on the street. They have great bite even cold.

autoxer6

I have used XP10 / XP8 on PS2 tires on my C5Z. They aren't too overpowering for the street tires and modulated nice. You wont be able to overheat them in 3 laps. XP8/XP8 may be just fine for you and will give you a more consistent first lap. I dont think you would overheat them either.

Be carefull on the street with cold (less than 50 deg) and rain. I had a couple of scares leaving a parking lot with a cold car and it wouldn't slow down from 15 MPH for the first 10 ft or so.

XP16 and XP20 is very overpowering for street tires and take too long to heat up.

Dont forget to put some good fluid in there before you start.

Have fun! Send updates!

Adam@Amp'dAutosport.com

We run 1 less in the back for better brake bias. You can run XP8 square but I would not run XP10 square. The Ideal set up with only 3 laps maybe to run the XP8 front and the AX6 rear I need to look in my notes as I beleave I have a few customers running this set up and they liked it alot. If you are interested in going with Carbotech pads give me a call and we can get you the correct set up

fmcokc

Does Carbotech publish any charts showing the mu of the various pads plotted against the temp like many other brake pad manufacturers do?

The only thing holding me back from ordering the xp8's is my prior experience with the pad on a different car. I found them to have a more compressible feel and maybe not as linear as I would like. We used to use the xp10's on several other cars and I really liked the way they feel I just think it might be too much for these tires.

How does the xp8 and xp10 compare directly to the XR2 Cobalt in terms of mu along the temp curve and initial bite?

wtb-z

Another pad you could consider is the Project Mu Club Racer

Reasonable cool bite, much more rotor friendly than the Hawks. Does not seem to be a super high temp pad but is fine for three laps.

bluemagoo

Came across this article this evening while reading Speed News - see pages 50-53....
http://www.snmagcurrent.com/publication/?i=135777