fhturner

Hey Guys--

Well, after running up to 160mph (w/ more to go) at Road Atlanta last weekend in my 580HP Red Beast 2, then not being able to comfortably bleed off that speed down into Turn 10a , I realized I'd found the limits of the factory braking system. I've really enjoyed the Wilwood H pads, but the stock-replacement rotors crack after 2 days, warp before that, and the clamping force just isn't enough for those speeds.

So, I'm interested in an upgrade to one of the racing-oriented big brake kits. I know there has been much discussion, but it usually seems to focus on one brand. My first thought goes to StopTech, but I know AP Racing and Brembo make good setups as well.

I would love to hear a discussion comparing the different brands and their advantages/disadvantages relative to one another. I also have some specific questions. Your input would be greatly appreciated!

1. I recently read that ST-40s could be used on the front w/ little loss (if any) in performance vs. ST-60s. Verification or contradiction of this? Put another way, is the $400 price increase for ST-60 worthwhile?

2. Do most of you guys run a 14" rotor? I read on another thread that its advantages are lighter weight and easier wheel selection.

3. I am unable to afford a full set of all 4 corners at the current time, so what is the recommended course of action for the rear? Leave it stock for now? I've heard of moving the fronts to the rear, but that there then becomes a master cylinder fluid volume issue.

4. I have 2 sets of rear C5 Z06 wheels (18" x 10.5"). One set is OEM, one is repro w/ noticeably thicker spokes. Will any of these kits have interference issues w/ my wheels?

5. Do all systems have common pad sizes, and therefore reasonable pad costs? IOW, will one brand/model require significantly more expensive pads?

5a. Do any of the available options support a thicker pad? And if so, does that impact wheel fitment?

I'm sure I'll think of more, but comparisons and answers to these questions for starters would most welcome! If my research hasn't been thorough enough, feel free to link to prior threads that might've already answered my questions.

Thanks,
FT

AU N EGL

What is your budget ?

That would be the place to start.

$5,000 ?

$6,000 ?

$10,000 ?


But you say that all four courners are not in your budegt. Which is OK

Stoptechs 6 pot fronts or Wilwood 6 pot fronts and stock C6 front calipers on the rear.

fhturner

Well, it looks like the most common of these kits are in the $2500-3500 range for one axle. I could do one of those, but not 2.

What about the issue w/ not having enough fluid or pressure when moving the stock fronts to the rear? Is there a workaround or way to avoid that problem?

Thx,
FT

AU N EGL

the Stoptechs will work with the stock MC and brake booster.

remember the Right Front goes on the Left rear. Keep the bleed valve on the top of the caliper.

when using front calipers on the rear, you loose the emergency brake

oldmansan

I talked directly to Stoptech and was told that in a blind comparison of two identical cars with ST-40 and ST-60 calipers, I wouldn't be able to tell a difference. They also stated there would be no performance difference (shorter stopping distances). The effective clamping is the same. The ST-60 pad is larger, so it will last longer. It is heavier, and the pads are quite a bit more expensive.

With proper ducting I can't justify a 15" rotor. Not saying some don't need it, and I'm hard on brakes, but with the weight of the C6 I think with ducting, SRF and titanium backing plates, 14" will be fine. The ST-60s with 15" rotors would look cooler, but I will upgrade in the future if I feel the need to be cooler.

San

GrantB

I'm going with a widened W6A/BSL4 Wilwood setup from Todd @ TCE. My reasons are:

Cheaper pads. $210 for Wilwood H or Cobalt Friction XR1s.
Cheaper kit cost.
Cheaper rotors, $200/$170 fronts/rears (fronts are Coleman, rears are Wilwood)
Larger front rotors still able to fit under OE C5Z rears, 14.25x1.375" vs. 14.0x1.250" on other kits (even more volume than StopTech's 15.0x1.25" rotors, which I briefly considered)
Rear rotors are smaller and lighter, 12.9x1.0".

Are the W6As as stiff as ST-40s? I don't know, but I do know their pads have more volume, are more than 50% cheaper, and the rotors should last longer.

I haven't gotten the setup yet, though. When I do I'll weigh everything and take pics of it all. The piston volumes and overall leverage of the master cylinder on the tires comes out to be pretty close to stock (W6A piston volume is 4.04 vs. 3.84 stock, BSL4 is 2.46 vs. 2.41). It should add about 9% more bias to the front, which might not work well for other people (with my bias spring I seem to lock the rears up before the fronts).

trackboss

I'd say stoptech is the best bang for the buck. Equivalent system from brembo for example is quite a bit higher. Brembo makes some great products, but personally I would only buy their race systems that have the pewter anodizing on the calipers if I were going that route. Of all the powdercoated calipers I'd say there is no performance improvement by spending any more than stoptechs go for.

kmagvette

What a timely thread...I just put the DRM 6 pot AP Racing fronts (14" rotors) on my C5 Z06. I was worried about the amount of fluid these would need to move while still using the stock cylinder and stock rears; it is a non-issue.

The brake pedal is ultra firm and there is very little travel, way less than there was with the stock fronts. The braking force is so amazing that I think I may be able to do a stoppie

It may be the case that the fronts are so good that I now have inadequate relative clamping forces out back. So I believe I am at the same crossroad the OP will be at as soon as he upgrades his fronts.

Since 3K more on the back is not an option, I guess my options are:

1. Go with a adjustable bias master cylinder
2. Find another caliper solution for the rears: used g-stop, stoptech, AP (good luck), stock fronts

Unless I go with stock fronts on the rear, I really don't want a cylinder that moves more fluid unless it is major adjustable. The pedal is so firm now that increasing the hydraulic advantage up front in any way would seriously impede brake feel.

FWIW - My 18" CCW Classics clear the AP monster fronts with 0.250 spacers.

fhturner

For add'l discussion, here's what a friend of mine said in an email reply:

fhturner

Not a problem for me...already chunked mine due to them not wanting to let go of the rotors when doing rotor changes at the track...

So, is the larger pad which lasts longer the ONLY benefit to the ST60s? I would think there'd have to be something else to justify it...

What was the approximate cost of this setup, particularly the front axle set? How thick a pad will it take up front?

What made you decide to go w/ this setup? Most of the discussion here seems to be StopTech and some Brembo, but very little AP Racing. I'm very interested how these compare to StopTechs.

John Shiels

Larger ST-60 pad would make it take the heat better along with the caliper of the ST-60. Why scrimp for a few bucks you can't have to much braking in reserve.

GrantB

$2300 for the fronts, or around $2180 if you want the standard Wilwood rotors. I'm still working out fitment with Todd to fit the wider Coleman rotors, hopefully it should be pretty easy.

Rears were $1790 for the 'race' kit with aluminum hats. If you want the iron hatted version to use an e-brake with its actually cheaper at $1504 (comes with aluminum pistons and a street pad, though).

Wilwood doesn't publish the thickness of the friction surface itself, probably because pad volume is a more important figure? Whatever the case, total thickness (with backing plate) is 17mm and pad volume is 5.2in^2. Looking at their dimensions, the pads are definitely larger in volume than ST-40s and definitely smaller than ST-60s. I'd say about halfway in-between the two.

I've heard great things about the longevity of the Wilwood H pads, but I think I'll probably end up going with Cobalt Friction XR1s because they should also last a very long time, and most say are easier on rotors.

The biggest thing attracting me to the Wilwood setup was the larger front rotors and great pad volume per dollar ratio. Rotors seem to be the biggest heat sink in the system by far, and are also the biggest PITA to replace.

bowmanized

oldmansan

The ST-60s are 6-piston compared to 4-piston, so theoretically you might have less pad taper. I actually thought about selling my ST-40 front setup and "upgrading" to the ST-60s, but after talking to Stoptech I will stay the course. Every conversation I've had with Stoptech makes me feel like I made the right decision.

San

meldog21

Those Brembos are so nice and new. This is what the Stoptechs (or probably any brakes) look like after a day or two at the track:









I have the ST40's on 14" rotors front, stock calipers with 14" rotors rear.

Dog

fhturner

Alright, so a whole bunch of pix of pretty Brembos, but gimme some "fax, jack!" Advantages? Disadvantages?

C5ZEE06

there was a C5Z at the track today with f/r 4 pot Alcon / Baer calipers with 13" f/r baer 2 piece rotors.
anyone have experience with this set-up ? is it in the same league as the stoptechs / brembos, etc ?

oldmansan

Unless the C5Z is really light I think the rotors are too small. I also believe the Baer rotors are drilled, which isn't a good thing IMHO. I personally think the Alcon calipers are in the same league, but not the Baers.

San

AU N EGL

Braking also has a lot to do with driving style and the front tires you run.

I have done 160-163 in to Road Atlanta T10 several times on stock C5 calipers, Wilwood H pads, and did not have any problems. Braked at #4

i also use a 305 tire on the front so plenty of rubber to assist in braking.
The calipers are tossed each winter. Been using the C6 caliper this past two years.

My choice for a BBK would be 1) Stoptech 2) AP Racing. based on costs.

If the prices were close, then AP Racing.

Stick with a 14" two piece rotor do to wt.

DRM and ZIP have APRacing kits that work on a C5 or C6.

I start to drool when I see these on eBay









Raybestos /Alcon

drivinhard

Might want to check your spokes on the repro's. Posted this awhile back:

http://forums.corvetteforum.com/auto...clearance.html

And beyond that, I'd re-think running on the track with some boat anchor chinese made beer can alloy wheel anyway

Grant B...interested in your 1.3"+ wide WW set up when you get it. Weights, C5Z rear wheel clearance, etc.

Great thread btw, I am ready to dump some points somewhere to gain some points elsewhere (for brakes) in my TT class as I am very much ready to dump the stock brakes. I remember how long I used to run WW pads and coleman rotors on another car, and I'm ready to get back to that.