jstout

Building a C4 car for Chanp series. Long endurance races each day. Hearing more and more about guys with Wilwoods having braking issues and weird pad wear issues. If I don't go with Wilwood, then who is a competitor that is not super expensive?

MarkBychowski

I had Wilwood GN3's on the front of my C4 with the factory J55's moved to the rear (the setup that Doug Rippie used to sell). I did end up upgrading the master cylinder (larger volume) because the pedal was a little soft. Braking was great with PFC-01 pads (this was around 8 years ago), never had any braking issues. I did have some uneven pad wear on the fronts though -- both sides of the pads would wear a little crooked (about 1/16" front to back of the pads), but nothing that impacted performance.

strano@stranoparts.com

One of the most frustrating things to deal with for me is when folks start worrying about things they read on the internet. And largely there is more bad than good out there, both in terms of what folks say, but also advice.

The Superlite 6 isn't the BEST caliper in the world, but far better than OEM and if it's a late C4 that's really your only choice.. I suspect most taper wear issues are stemming from other things, and could be lots of things.

I don't know what C4 we are talking about which makes it kind of hard to look at options, but think of it this way. Do you think a 6 piston setup with staggered pistons will be worse than the stock 2 piston setup? Stock type calipers are much more prone to taper wear due to the fact there isn't force squeezing from the outside to counter the inside force from the pistons. And the two pistons are the same size. When a pad is gripping a rotor, that friction pulls on the pad, which is in the caliper, twisting it, which applies forces so that the bottom of the inside pad is pulled making for more wear there, and the top of the outer pad too. This is why most 6 piston and some 4 piston, (but not all of either) calipers stagger the piston size, to try and keep the pad as square as possible to the disc when running at speed.

Other things cause taper wear too, like less than solid wheel bearings. See also why Xtrackers are a good thing, and yes there ia kit to run those on the front of at least some C4's, later cars for sure. Not sure about early ones though.

Daniel_Mc

Been running the DRM set up Wilwoods (GN3's front Superlite rear) since 09 with no issues.

BrianCunningham

I have a set of the larger Wilwoods
Never mounted them up since my 18x12 wheels would require a 1/4 spacer to get the to fit
that would make these particular wheels hit the bodywork.

I'm assuming you guys are running brake ducts

jstout

Thanks for all the responses. Actually got this feedback from actual racers that I know running the Wilwood set ups. The series I will be building this car for doesn't allow 6 piston fronts without penalty points, and the car starts high in points as a bone stock car, so I can't run the 6 pots. I will look into the other ideas presented here and appreciate them. This car is a 91 model car. I can pick up the J55 brakes pretty reasonably and if they work well on the rear since most braking done by the fronts, that would be great. Again, thanks for the feedback. Jerry

AZSP33D

JSTOUT: Perhaps get in touch with Wilwood and order a custom kit pieced together to change up the calipers a bit, and if your doing fronts only, there's a 4 piston forged non-directional version of the Forged Superlite. Fits the same pads, but the six piston design reduces tendency to taper. The FSNL4 and FSNL6 have the same mounting pad and use the same pads, weigh almost exactly the same even, and less of a long pedal issue which is a very long pedal by the way.

Here's the kit for the front with 12" rotors
https://www.wilwood.com/PDF/DataSheets/ds479.pdf

For the 18" wheels, here's the front pre-assembled kit with larger rotors :
https://www.wilwood.com/PDF/DataSheets/ds538.pdf

Avoid the drilled rotors, they also come in slotted.

The J55 PBR's are good calipers but nowhere near as solid and trackworthy as the Wilwood forged superlite. You also have to fix the brake system light rear bias issue. If you're not quite so budget sensitive (not that a $3400 set of brakes are cheap), Wilwood has more advanced calipers and rotors, and you can then look at the Brembos and the Alcons and Stoptechs but fitment will be tougher.

jstout

Thanks for that info. Very helpful. and appreciated. Jerry

jstout

Budget is an issue so looking for the best bang for the buck!

Nokones

6 piston 6S Baers front and rear on my 89. The package also has the Parking Brake system included. The rotors are 14"

BrianCunningham

Functional parking brakes are a big thing.

chetly

Do you still drive the C4 Ken? Definitely a cool c4 that is built to the 9’s.

Nokones

I was up to last August. The clutch started to slip so I stopped driving it. I've been driving my Grand Sport on the meantime. It took all this time to get a clutch because of the shortage of materials. The clutch finally came in about a week ago so the car went to the shop last week and they discovered a problem with the tranny input shift. The shop is a Tremec distributor so they have all the parts in stock to fix the tranny. I should get the car back today or tomorrow. Now, I'm waiting for a 200 treadware tire in a 345 size to become available. I won't run the BFGs until they have a better tire. Continental/Hoosier should have their 345 tire out sometime soon.

chetly

Good to hear that you’re still driving it. I’ve heard that the Continental in general is more of a track day tire, not an autocross tire but your results may very. Sean wanted to get the Conti as well until he found out it wasn’t an autocross specific tire like the other 200tw tires are.

Nokones

Sam Strano said, don't overlook the fact that they are more for endurance. They'll work just fine and probably be the tire for Arizona weather during the warmer months.

BobsRedVette

C5 Calipers with Carbotech XP12

Kubs

I have heard that they are working on a 'sprint; version also. Dont know when it will come out though. If not by end of March this year we wont be able to use it until 2023 anyway.