What do the surface of the pads look like? To be honest, I've never seen a condition like that on a rotor. I would think your pads would glaze up well before your rotors. Try rubbing a smallish area of the rotor with a ScotchBrite pad to see if that white comes off. Also, what does the area on the body of the car behind the wheels look like in terms of brake dust?

 

So when I inspected the brakes between each track weekend, I didn't see anything odd. But then again, I wasn't specifically looking for any sort of glazing. I was primarily checking for wear or if any chunks of the pads came off.

But the next time I check my brakes, I'll check the pads and see what comes off of the rotors too. If they are glazed/shiny, does that mean I've overheated them and exceeded the capacity of the stock brakes?

 

I don't know the answer to your question. But I thought you were running aftermarket race pads and rotors.

I'm not any sort of expert but in my limited experience, rotors are inclined to crack and perhaps warp. I've never had this as a major issue, but I've been careful to drive around the spare paddock several times to cool the brakes prior to parking, and then when I park, to roll the car a couple of feet after 3 or 4 minutes to lessen a heat soak between the pads and rotor. And I don't shock the rotors by driving through any puddles. Cracking usually starts with hairline cracks that get worse over time. But an actual cracked rotor can also occur more suddenly during a run and you will know it. If there is any glazing on the rotor, I would think it is pad material, not the metal rotor.

When I've had glazing, it has occurred on the pads, not the rotors. I believe the glazing was caused pads whose temperature range was not high enough. I had a sense of the pads not grabbing as well as previously. I would pull the pads and grind the surfaces of the pads on the pavement to remove the glaze, but the long term solution was to change to a pad with a higher heat range.

During high temperatures, all pads leach binding material. But a pad with a too cool temperature range leaches material aggressively and will start to disintegrate with cracks and chips and chunks falling off. The glazing of the pad starts earlier and is quite obvious when it is present. But a pad is supposed to transfer material to the rotor. That is what bedding the brakes is all about. So the material on your rotors is probably pad material.

 

I am running aftermarket pads with centric blank rotors. Using Project Mu 999 pads, not sure if those count as "race" pads but maybe?

My previous rotors had surface level cracks when they were swapped out, but nothing unusable. I also wasn't pushing them as hard in the 1st year, so maybe this is just how things are.

 

Mine started wearing kind of like that after many track days. More pressure being applied towards the outer edge than towards the center. Tried measuring and a few other things to figure it out, but given that the calipers were pretty cooked, including the boots and they had 164,000 miles plust many track days I just replaced the front calipers and everything was normal again. I never got around to doing some comparison measurements between old and new to determine what exactly was going on. I suspect that the slider pins/slider pin area was warping/bent but like I said, did not spend any real time trying to confirm

 

Glad to see you out on track. Re: your rotor question, does your rotor have a lip at the top where your fingernail catches it? Also does your rotor have a taper between top and bottom?

My best guess is you’re definitely using an endurance pad designed for heavy GT cars with downforce. While I get why someone would recommend it due to its ability to soak up heat, it is likely not wearing or performing appropriately. Yes the S2000 brakes get hot but if the temps are not constant you will get uneven or inconsistent pad performance. If you went with Project Mu Club Racer at the front I would be curious if you would have the same result. I think the pads are cooling too much which is why the wear is not consistent. I also assume this car is driving on the street to and from the track which could contribute to eating of the pads and rotors. It’s too cold for its performance window.

For your next pad try the Racing777 or the Endless ME20 front and rear (keep the same pad material front and rear). The heat generation on the front rotors will need attention in the future as you get faster.

When track pads are bedded appropriately there should be some smearing or light pad material transferred to the rotor.

Note: the operating temp for the Racing777 is 300c which would take a bit for it to come up to temp while the ME20 is 150c. However the Racing777 shouldn’t be used on the street as with the Racing999.

PS I like your Mugen seat. I have the bucket version (rated for racing until 2029 as it’s less than a year old) and if I can get my car sorted it might be up for sale. These seats fit the S2000 perfectly. Just a bit narrow in the seat.

 

I had uneven wear in the prior set, which was Project Mu Club Racer. I've spoken to few other people too and the general consensus is that this is just what the stock S2000 parts bin braking system do under the demands of high performance driving.

Regarding your Mugen full bucket version, I thought about it at the time of purchase. Maybe it'll be something I eventually "upgrade" over to, and move my current semi-bucket version over to the passenger side. Is your full bucket version cushioned and sit just like a normal seat?

Yeah, my seat is narrow too, which holds me in place perfectly. I've had others sit in it and they're rethinking their seat choices... haha

 

That rotor wear does not look normal to me. It looks like your rotors and pads are not getting up to operating temperatures, or your pads are well above it and glazing. The rotors don't have any microcracks which shows you're not using them very much.

What fluid are you using?