Wilwood Failure
 

https://sphotos-a.xx.fbcdn.net/hphot...33023904_n.jpg

Found this on an S2ki.com. Figured it'd be interesting to talk about considering the similarities between our two cars. The car was running RS3's when it went. This was an on track failure.

Has Wilwood had any recent design improvements to rectify this type of failure? The thread wasn't that old, not sure when the pic was taken.

Cheers
Nathan

Wow! at first glance I thought someone had put on a calipar that was too big for a rotor, then I saw how the rotor had broken.

that would be scary to experience on the track. Brakes are one upgrade that I will in no doubt spend top dollar on!!!

This was on a rather well known time attack car... those are JRZs you see in the back. The pic is less than a month old; I was there when it happened.

The key thing to notice here is the way the rotor mounts onto the top hat versus the AP Racing kit.

I am not a fan of these types of conversation because too little is known about the situation, system condition, or really anything for that matter. This only produces paranoia aimed at a particular company. Something that could have caused this for instance is improper heating of the rotor in its beginning life. Important processes such as "seasoning" is crucial and often overlooked. There is really just too many things that could have caused this to begin to hate on any particular product. The most expensive systems $$ can buy can still fail if used or broken-in improperly.

Just my 2 cents

EDIT: After I posted I see there was a response that indicated the vehicle is a well known time attack car so I imagine there was proper heating cycles conducted before put into service as a track vehicle. I still think more data is needed to determine what actually caused the failure.

I agree and OP didn't even include the original thread.

What do you mean by "seasoning"?

:popcorn::popcorn::popcorn:

The kit on that car is specifically built for the car. I can assure you this car has more man-hour in the build than all but the most extreme builds, and is meticulously maintained.

The failure itself is pretty evident in the photo.

How many miles were put on that brake kit alone?

Seasoning a rotor or prepping a rotor for race duty requires a process of heat cycling. Just as any metal reacts under heat there is expansion and contraction of the rotor as it cycles through heat ranges. This expansion and contraction if done improperly can cause stress cracks. Typically premature excessive heating in the beginning of a new rotor can cause the most damage. The rotors have to be brought up to temp gradually, then essentially cooled, then brought up to temp and then some, then cooled, then brought up to temp and then extreme temp, then cooled. This can often be a couple days worth of process and the processes can vary just as engine break-ins do. Without going into the technical science of it you are basically arranging the molecules of the metal to have an evenly hardened rotor that has been done in a way that is specific to the vehicle in which it is being used on.

After that you can go a step further with a process of bedding your pads.

The failure is evident but the cause is not

Did he ever inspect the mounting "ears" where it mounts to the hat? Not the easiest to do, I check mine as much as I can after removing pads, but removing the caliper is somewhat annoying just to check..

http://www.s2ki.com/s2000/topic/1012964-2piece-rotors/

@AZFA20-Happy? :) There wasn't a ton of info there either. I've been researching 2-piece stuff lately as I'm interested in some of the 2 piece options for the stock calipers as well as a potential upgrade to fixed calipers and I want to know all I can about how they work and the potential problems before I do anything.

I'm pretty sure brake rotors are heat treated from the factory correct? You're probably right about doing sets of heat cycles before really hammering on them, but this is a kind of failure that I feel should basically NEVER happen. It's one thing to microcrack or warp a rotor. It's another thing to have a rotor completely SEPARATE from the hat. That's just plain dangerous. The parts should be designed so that the margin of safety is high enough on that portion of the rotor that it's an extremely unlikely place to fail first.

I'd be more than happy to have Wilwood step up and talk about this, that's kind of the point of the thread. Brakes are an item of utmost importance when it comes to safety and unless something was blatantly done wrong in this case, this is a safety issue.

Cheers
Nathan

Really need to hear a first hand explanation of what happened for this to have any validity.

Anyone can google image search for days finding pictures of broken parts.

Quick example. A buddy of mine has a broken team dynamics wheel hanging on his wall. The wheel was off his rally car. Some dude saw it and then decided TD wheels were weak. My buddy pointed out that he should have seen the rest of the car, a high speed impact with the wheel caused an end over end tumble. Any wheel would have broken.

Nathan, I hope you didn't take my need for info as a personal attack. It wasn't I assure you :happy0180:

I agree brakes are a very critical component but I also know that things often times fail not necessarily due to a design flaw. By no stretch of imagination am I saying there may not be a design issue but I just know how these types of threads scare people from certain brands based on one failure they observe via a single picture or freak incident. I actually personally own the same style Wilwoods on one of my cars (I understand these are specific for the car in question but Wilwoods are basically parts bin brake kits) so this failure is something that directly concerns me too. You won't see me necessarily worrying about a failure though without more info. I would love to see Wilwood address this particular failure myself to be honest but perhaps through constructive conversation we can figure it out :w00t:

As far as the heat cycling from the factory, yes they usually are but remember these are two-piece rotors so the same friction surface is used for many vehicles which each produce slightly different heating characteristics. The rotors should always be seasoned if used for racing.