yow

I'm getting a Wilwood bbk for the front of my c5z. It'll have H compound pads. I do about 8-10 HPDE days/year and plan to do NASA TT-2 with this car in the next year or so.

After getting the bbk, what rear pads should I put on my stock calipers and napa blanks? Looking for input because my next HPDE is 7/10-12 at NCM.

Setup: Stock motor/trans/dif, DRM EOC, Dewitt radiator, GM T1 sways, Callaway Eibach coilovers, aero, DRM brake ducts up front, stock ducting in rear, seats/harnesses, and otherwise stock. Aligned and corner balanced by Vettesport, who is also doing my bbk.

Thanks!

UstaB-GS549

Just run the same pads that you used before, assuming that you currently use Wilwood H pads in front now.

edge04

will ley others that run wilwoods chime in

questions if you don't mind. How long you been running the eibach's? how do you like them? and are you running full coils or the helper springs with stock leafs? where do you have your shock settings at?

I just installed them but I had to run them without the front springs to get the right ride height and corner balance. having a hard time getting them dialed in. would think that the rear would be super stiff with the springs in and not in front. I have my sway bar set to the loosest setting.

SunnydayDILYSI

I'd run the same pads as in front, or more aggressive if you can. I put the Wilwood based LG kit up front (uses stock rotors and wheels). It helped greatly, but pushed bias to the front. When I added the rear Wilwood kit (link below), it made a huge difference in brake performance. Incredibly consistent and powerful. I can see why an even larger BBK would be beneficial though. I rarely get into ABS, even when standing on the brake. I have leftover stock rear Carbotech RP2s if you are interested, will give a great price (just sitting on my shelf).

http://www.wilwood.com/BrakeKits/Bra...on=C-5+%26+Z06

ZedO6

I'm running a C5 with the Wilwood 14.25" BBk with stock rear calipers and a similar suspension setup as yours.

I like the H pads in front and Raybestos ST47 in the rear. I maintain that with equal pads, the setup could use more rear brake bias. The ST47's seem to accomplish this. BTW, this brake setup is incredible. High firm pedal for the entire session and stopping performance that will have you reassessing your braking points. The H pads are underrated. IMHO. I made my purchase from Todd at TCE and can't say enough good about that vendor.

yow

I've been using Carbotech XP20/12s on stock brakes.

I bought the car in November with the co's already on it. I can't adequately review them. Vettesport set them for me and I trust his judgment.

Can you email me pics and a price? yow@ericyow.com
Looks like the RP2 will give me the brake bias suggested by more than one response, here.

I researched the ST47s, just now, and I think you're right about the bias. I may try those!

I'm on NT01s at the moment, but will go to R7s after I blow through them.

Thanks for everyone's help!

0Todd TCE

There are Wilwood Poly H pads for the stock rear calipers: D732




In stock.

z06801

Did anybody mention you can move your stock fronts to the rear? I find it works great me. Doug Rippy makes a nice stainless piston kit for them too.

NemesisC5

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yow

I looked into this at one time. Does this require a fabricated bracket or does it bolt right up? I understand you lose the parking brake with this set up, which makes it less appealing to me. I still drive my car to work fairly regularly, especially in the 'off season'.

ZedO6

Based on my consumables use, the rear brakes do so little on my car that I can't see any benefit to upgrading them. A big factor here is weight transfer under braking and no aero. I don't have coil overs which probably influence the weight transfer but I think any coil over setup that is acceptable on the street is still too soft to appreciably impact this situation.

Using a slightly more aggressive pad on the rear seems to add some rear brake bias, but I'm talking small percentages.

Socko

I just went to a fsl6r setup on my front. The car was excellent on track but my rear caliper pistons are warped to hell so need to go. For the money of new stockers and c6z51 brackets i think i can move to a fsl4r. The matching newer(cheaper) full width fsl4r are out now. So I think i am just going to pull the ebrake off and throw them on the rear. Then i can run front rotors on all 4 corners and the same pads.

The rear pads are super small and i do use them, they only last maybe 4-6 track days where as i think the 7420 in the front lasts about 6. I feel like going to the relatively huge, i believe 3 times larger cubic inch, 7420 in the rear will be super nice. Then i will just run same pads front and rear and can get max life out of everything. Will cost under $600 as i already have the brackets and the fsl4r are like $229 each on summit.

It also gives me the ability to get adventurous. I wonder what a 14" c6z rotor in the rear with a 12.8" c5 rotor in the front would feel like. That would be worth some legit brake bias!

z06801

You do loose the E brake, but does bolt up.

SunnydayDILYSI

I have similar experience and setup. The rear kit that I posted a link to above (and have on my car) runs 7416s in the rear but also still has an e-brake. As my 7420s wear down up front, I just rotate them to the back (same shape, just 4 mm less thick). Huge difference in consistency of brake feel, pad life, rotor life, and brake distance. Doing the fronts first took ~1% off my lap time and then doing the rears took ~1% more off. Pad and rotor life is ~3x stock on front and rear. Lap time improvement comes ~50% from improved consistency / predictability, and 50% from improved braking performance. Pad / rotor life also allows me to think a lot less about whether I'm near a failure and more about my driving.

ZedO6

All good points and then throw these in: Not having to bring a complete set of rotors and pads to a two day event. If drive your track car to the track, that's probably 150 lbs of hardware that you have to load and unload twice. Now throw in swapping out hot cracked rotors at the track between sessions

Finally, when all this is done and over with and you move on, you pull the BBk, swap back the stock originals and recover 50-70% of your original purchase price. No brainer...

JeremyGSU

I get around 3 track days on my 7420's and 4-5 track days on my rear pads. I run XP20 and XP10's. Just bumped to 12's in the back.

I believe upgrading the rears can help. If I look at Porsche's, BMW's, and pretty much every other performance car their rear brakes are huge. The C5's are puny. Why is everyone else's so large if they don't do anything? I personally think if you're going to make the fronts larger that making the rears larger only helps equal out the equation.

That's just my opinion.

ZedO6

As you've indicated before, the front T1 BBK setup is probably inadequate for your driving ability and your local tracks like Sebring. I'd suggest trying a different pad manufacturer as well. I started out with the XP12/10 setup with my stock brakes and found them the shortest lasting race pad I've ever used. Maybe they are easier on the rotors but that's a non issue for me on C5 rotors, which crack long before they wear out. I only used them once, switching to Raybestos ST 47's which wore better and were very effective considering the limits of the stock system. I'm also impressed with the Wilwood H compound on my BBK.

When I offered up the opinion that upgrading the rears would not make a big difference in braking performance, I was talking specifically to my experience on my car, certainly YMMV. I've only run one event with the BBK and that track was not our most severe braking situation. However, I've just not had lots of wear or rotor issues on the rear of my C5Z while the fronts have been a constant issue prior to the 14.25" BBK.

The C5 was built to hit a price target and everything that could be scaled down to save money apparently was, including the rear brakes. How much that impacts track performance is a matter of opinion. Most Porsches are rear engined so the weight transfer under braking is not the same as the C5 and larger rear brakes make sense, plus the price point allows for real brakes. How long ago was the 911 MSRP the same $50K as a C5Z? BMW brakes IMHO are nothing special and while the rear sizing might be bigger than the C5, BMW's don't really come with track capable brake system. At least my E46 M3 didn't.

I've followed your car mods and look forward to the next installment of your brake upgrades Keep us posted

miracle_whip4130

One thing to keep in mind here is that if you increase the piston area on the rear calipers, you may have to get one of these bad boys to get brake pedal travel back down to a reasonable level:

http://dougrippie.com/products/drm-c...ster-cylinder/

CHJ In Virginia

Used the Wilwood SL6 kit on the front of my 03Z06 and stock calipers on the rear. With a set of fresh rear calipers and H pads all around, I found brakeing and overall balance to be excellent. This setup worked well for me.

JeremyGSU

Those are some good points. Porsche's have much better brake bias from weight than C5's. And you're right about the M3 too. My friend had a badass E46 race car and until he put a Stoptech 355 kit on the front it didn't brake great. After that it was nuts. I could never figure out the braking zones with his car because it braked so well. Of course, it had a TON of downforce and he got his M3 down to 2,7xx lbs making 355whp.

I haven't tried many pad compounds so perhaps before I spend a ton of money I should try other compounds. That is a very good point. I'll dig into that.

Thanks.