New Wilwood Calipers suck, help.
 

Hey guys, I'm looking for some help here as I am extremely frustrated after dropping 6k on a brand new set of Wilwood calipers, and testing ( AERO6 Front 140-12629 Rear 140-14026-N ) I also got these with upgraded Thermlock Pistons and their Polymatrix H pads and install. Before I made my purchase I called Wilwood and talked to their "Race Specialest" Carl. He is the one who gave me the part numbers and pads I needed. I had everything professionally installed by the same place that has been doing my brakes for years with no issues. Under normal street use the brakes feel great and normal, but when you need to stop fast they lock up and go into ABS right away, I thought this was odd but thought I would try them on the track with some R Compounds, Toyo R-888. At the track the problem was constant and consistmat, anymore than 30% force on the brake Pedal and straight into ABS. I tried switching the pads to Wilwoods street compound and that solved the locking up and ABS issue, however they didn't stop the car and I could feel them cooking. They were like my OEM street pads. The car takes way longer to stop with the Wilwood setup and H pads Vrs my OEM setup with Carbotech XP12s, ive taken my car back to the brake shop and again everything is installed perfectly, bled perfectly and as it should. The shop said it's possible that the calipers just don't work well with my master or the cars ABS system. I called Wilwood and again spoke to their specialist, Carl again, and he told me to try the Carbotech pads that worked so well for me on my stock calipers, so I did and got better results, however they still went into ABS way too soon. They still don't stop the car as fast as the OEM calipers did. All suspeonsion tires streets and tracks are all the same, the only thing that is different are the calipers.

Car is a 2011 GS 500RWHP

I use SRF fluid and SS brake lines.
DBA one price rotors

One thing I noticed is that the pads for the Wilwood Front rotors have 1/2" less surface are have 1/2" less surface area than the pads for my OEM calipers, also ,,I had to change my rear rotors out to fit the Wilwood calipers, my OEM rotors are 13.5" and had to install 13"

I called Wilwood again and asked for a Manger and spoke with "Dustin" after he spoke with the owner he said all they can offer is sending me some pre bed pads.

All I want is my stock braking capability back, unfortunately I sold my OEM stuff. Anyone out there with any advice other that stay away from WIlwood?

I loved my OEM braking system, the car stopped on a dime, I was onley upgrading for the thicker pads, lighter weight and cooler temps Wilwood offered. I never expected to stop any faster, but never imagined stopping wayyyyy later. I'm 4-5 seconds slower with Wilwood.

To me, it sounds like you now have more brake than tire. If you are engaging ABS with little pedal input, that tells me you have more stopping power than the "stickiness" of the tire can handle.

How old are your 888s and what size?

For what it is worth, I have the Wilwood W6 and W4 kits on my racecar. I can engage ABS in harder brake zones with 315 A7s. When the tires start to get heat cycled out, I can engage ABS more and more. When I run harder tires like an R or back to a 100 TW tire, the ABS is even more so. It all comes down to matching your tire to your braking capability.

yes I would agree that I have too much braking, but the problem is it's no longer linear braking that the OEM brakes gave me, now it's 30% or locked up.

My R-888s are 4 months old with 4 track days on them. My 3rd track day on this set was with OEM calipers and they worked great! Even when I ran my stock 5 year old run flats on the track ( used them because I just corded some Mich pilot super sports and didn't want to go home) I never had this issue with the OEM calipers. Yes I could get them into ABS but I still had better braking and longer range pedal than I do now.

i forgot to add that I am on stock GS rims and stock sizes.

Based on what brx said, maybe you need larger wheels with larger tires to now match your larger (capacity for stopping) calipers/pads. Of course, whatever wheels you get make sure before you buy them that they will clear the calipers---depending on offset that is not always a given. Or, buy your old setup new from Rock or Cultrag.

You may need a brake master cylinder with a bias adjustment. It sounds like you're getting too much pressure to the fronts.

I have a C5 Z06 running 275mm front Nitto NT-01's. I have an AP Racing 6pot front and 4pot rear kit with upgraded brake MC. The braking is incredibly balanced and I can really manage threshold braking very well. I run Hawk DTC-70 pads, which are the most hardcore of hardcore pads they sell.

I can get ABS to kick in on mine as well, but I have to really push it further. Get a brake bias adjuster, fiddle around with it and test it out. You may also need to adjust your braking style a bit if you have a habit of just slamming your foot down on the brake pedal. Threshold braking on the track requires a finesse.

Ok I think I've wrapped my head around what this is. These ARE caliper kits no BBKs. I know they did not come from me or I'd have set you up with the proper rear for the Z06 13.4" rotor. Nonetheless I'll open the conversation. And see if I can help you.


Regarding the problem at hand:

I'll cc what was said above about the tires also. But expand a bit.

First on that; yes it's possible to have "more brake than tire" meaning the torque of the pad/rotor exceeds that of the tire/road. For that reason alternative compounds are produced. I often suggest others to guys knowing they are not using all out race tires. You proved that point some by the pad change so we can all agree on this.

To say that the calipers are not compliant with the ABS...that's totally false and a bit alarming that a brake specialist would say that. ABS measures wheel rotation. A stock caliper, Wilwood or another brand won't change rotation. You can clamp the caliper with one, four or six or more pistons and so long as the wheel turns- the ABS is fine. More pistons don't make more clamping. More total area does. Speaking for anyone in the big brake business that we all know here if these are fit to a standard Corvette (not a dual mc set up race car) the front piston area is about 4 square inches..plus or minus maybe 5% just based on common piston sizes that mfg uses. All of them. Every supplier will net the same basic result on your car.

That being said if by chance you received "large bore" Aero6 calipers you could have the resultant problem. That could happen...the only way to know is to check the bore diameters on the calipers. But if it did...you'd have a terribly long and soft brake pedal as the area would jump nearly 50%.

The pads being a tad smaller: won't matter. Pad size in general does not effect braking. Clamping does. A larger pad does not make more force. It only lasts longer and spreads the load differently. Stand on a bathroom scale, then put on a shoe that is way too big. Shoe weight aside; you weigh the same. That's clamping.

It looks like you put smaller rotors on the rear as I noted earlier. Did you put on new ones? Put new ones on the front at the same time?

thanks for you inputs guys, I have tried changing my braking style drastically, and this kit I purchased from Wilwood was supposed to work seemlessly with my OEM setup with no rim, master cyclinder or other changes needed. I specifically asked all of these questions before I purchased this kit. Now they have no answers and I'm stuck with a car I can't use.

Whoa! I'm going to stop you right here on this point.

Proportioning valves DO NOT belong on front brakes. In only very, very rare occasions could that even be considered. (think rail dragster)

A prop valve does one thing: it reduces line pressure coming out. The harder you push the the pedal...the less front brake you'd get. (in a nut shell) This would be terribly dangerous and not even a last resort.

They are fit to the rear brakes to prevent wheel lock up- by way of pressure reduction. NEVER install this part in the front brake system.

I can feel your pain. But from one who has sold probably more than any other vendor I can assure you there's nothing faulty about the proven product. After all the time here with folks I wouldn't even be around anymore if that were the case. In no way suggesting you don't have a problem..just needing to sort it out.

Do you know anyone who could figure it out? I've got two very reputable brake shops telling me the car is working perfectly and both point to the Wilwood Calipers

How old were the front rotors you used?

Brand new DBA 3000 slotted front and back and they were bed in

sorry DBA 4000 T3 slotted rotors

The rotors were 'bed' or the pads?

rotors bed to the pads.

You purchased DBA rotors. Pre bed. Specifically to Poly H pads? Hmmmm...really??

You see where I've been going. Pretty sure that's not the case and the root of your problem. My money since the first fishing expedition has been on the mix match of pads and rotors.

My first thoughts were you ran the new stuff over the stock rotor post XP whatever. New oe rotors would not do that. The DBA stuff has nothing to do with changing friction Cf but if they were sold having been dyno bedded on any other pad than those of the Wilwood line you'd see the same problem; incompatible compounds.

A bit of he-said, she-said on what's what here. And at the risk of throwing more money into things: get a set of stock rotors, sand the pads on some 80 grit emery paper (flat surface) and do a proper bedding on those rotors. Pretty sure you'll see a huge change.

Dozens of these kits sold, and even the more costly 2pc hat/rotor share the same caliper. There's no issue related to ABS etc here it would have reared itself hundreds of brake kits ago over 10yrs.

I truly want to help your experience here and in now way blowing smoke up you...if you have further ABS issues I can say without a doubt it's not due to these products. I totally believe you have a problem, no beef that at all.

Here's a bump.
Interesting issue....good luck solving.

I have no answers.

I can comment there was no mention of a Tech 2 use ensuring the ABS valuing block is fully flushed with no air bubbles.
Else, maybe run through the service manual ABS system checks.

Again good luck.

Bump. Wish I could help.

I'm local if you need to do a "back to back" drive comparison with my stock 2013 GS. Also planning to be at Streets of Willow on the 26th of this month.

Pre bed as in I bed them in myself before I got to the track as I have always done with my stock Calipers pads and rotors. The rotors were brand new out of the box so no Carbotech material was left on them. When I did switch to Carbotech to try them, after the Pailymatrix H, the shop sanded every disc before they installed them and I bed then in as well. I know that isn't as good as doing it on a machine, but it's never been an issue before, also, better bedding gives you more grip, something I have too much of alrwady

thank you, and yes brakes were bled with a T2. They also feel great, not spongy, they feel solid, they just lockup with minimal pressure. No linier Pedal at all. Tap and then lock. No in between.