SunnydayDILYSI

Looking to upgrade front brakes from the LG/Wilwood setup for stock 17" wheels to improve rotor/bearing/ball joint life and, to a lesser extent, brake performance (track car). I'm hoping that those who have experience running the rear C5Z06 wheels up front with BBKs such as the Stoptech St-60 will provide some guidance and advice. Initial questions are...

What size spacers are required to clear the brakes and to help from damaging brake ducts (also, any suggested vendors for the spacers)?

Are you still running stock rear calipers, if not, which are you running?

Did you upgrade the stock master cylinder to push more bias to the rear?

What size tires are you running front and rear (please also note what anti-sway bar setup you are running)?

If you happened to go from a 17" wheel BBK to the 18" wheel BBK as well, what differences did you experience?

Any other sage advice?

Thanks,
Chris

0Todd TCE

Couple of thoughts:

1. Moving to 18" wheels will afford you a huge variety of options you do not have with 17s. Rotor mass and diameter are your main benefactors. Did I mention rotor mass and diameter?? lol Heat, heat, heat....the enemy of smaller rotors. While you may have some benefits of alternate calipers, pads and ss hoses you have not addressed the physics of stopping: generating heat. Of any one single change that will net you more longevity, durability and cost effectiveness; it's rotor mass.

2. A C5 is a prime candidate for retro fit of C6Z06 rotors with much larger caliper options. Sure a few bucks more....but ohh those 14" rotors up front and 13.4s out back...will pay for themselves over time in reliability.

3. While a new mc may be nice (although seldom needed) there's no way you can change brake bias with one. It's a single bore, dual outlet until providing the same pressure to each end of the car. Any internal proportioning valve only reduces the rear pressure it cannot increase it.

4. Doing some of 2 however can and will allow you to exploit that bias a bit. Something you cannot do on a caliper kit for stock 13" rotors.


Absolutely no, zero, not an ounce of negative comment here on the proposed front kit- if you are keeping the 17s. It makes all the sense in the world for lighter weight, easy pad changes, better tactical response and feel....total agreement. But because you mention 18s....it's a whole new ballpark.

C5 Hardtop

How do you think upgrading brakes will improve wheel bearing life? I'm confused.

SunnydayDILYSI

From what I've read, the increased mass, surface area, and vents of larger rotors leads to lower operating temps. If the rotor is operating at a lower temp, then it transfers less heat to the bearing. Lower bearing temp also leads to less wear. I don't have any data to back it up, but makes sense to me.

0Todd TCE

I think I'd agree with that to a point. Moving farther up the food chain to 2pc hats and rotors (alum hats) one could argue yet more gains. But in fairness I don't think I'd ever market brake parts/kits as an item with those goals in mind. More of a side benefit. When you move deeper into "track day" use everything starts to take a beating and wear/tear is just part of that trade off.

ZedO6

I run a square setup on my C5Z with a Wilwood BBK, front only. I was tired of having a soft pedal 1/2 way through a 30 minute session, excessive pad taper, and cracking stock rotors sometimes twice a weekend.

I looked at all the options from larger C6Z rotors with racing type 6 piston calipers, to true racing brakes with stainless caliper pistons and full floating rotors. I considered all the popular brands, AP, Brembo, Stoptech and Wilwood. For me, any stock Corvette rotor was not going to give acceptable wear and the sizing is limited, I only wanted to do this upgrade once.

I ended going with the the Wilwood 14.25" BBk with the Aero6 calipers. This kit offers slotted 72 curved-vane racing rotors, 6 piston caliper and a decent sized pad. The reduction in consumables cost is real. After 500 track miles I measure over 75% of the original pad thickness. The rotors look great as well. I'm done worrying about my brakes and swapping hot cracked rotors between sessions, or flipping tapered pads. Best of all the C5Z 10.5 X 18's clear without spacers. I purchased from TCE. Todd went beyond my expectations and custom configured the kit to my specs, not all suppliers will do that.

Other data points:

Stock rear brakes and M/C. I run a very aggressive rear pad compound (ST-47) which seems to balance well with the Wilwood H compound I run in the front. With a mostly stock suspension, so much weight transfers under braking that the rear brake performance is not an issue for me.

Track alignment, T1 bars, 285/35-18 on 10.5" X 18" C5Z rears.

C5 Hardtop

Sounds logical. I didn't think of that. I had the idea its the additional stress that leads to faster bearing wear, but I don't have scientific data to back that up.

SunnydayDILYSI

I'm sure stress is 90%+ of bearing wear, but it never hurts to also keep things cool. I've burnt off tie rod and ball joint boots as well. As Todd said, rotor and pad life is really the main reason for a BBK, but the extra benefits of keeping everything around the brakes a bit cooler is a nice extra benefit.

fmcokc

Running ST-40's front and rear on a 2003 Z06 with square rear Z06 wheels.

No spacers-no ducts-Raybestos ST-43 pads.
ST-40 calipers
Stock M/C
295/35-18 Michelin PSS
Pfadt sways

Will pull your face off...

Use less brakes