Local track temps are pretty high and the other s2000 owners I used to track with had rotor cracking issues regardless if they did cooldown or not. I have a ducting kit custom made which I believe gas reduced my cracking likelihood.

The way i see it, if u limit the amount of heat transferred to the rotor, the chance of cracking should be reduced greatly. I've never cracked rotors(except for having those tiny hairline ones) even when i ran my discs til they were pretty thin

 

Rotor life is not the only variable. You should take into account pad wear also. After four track sessions at Buttonwillow in 85-100F heat, I got 0.8mm of pad wear on DS3000 pads (roughly equivalent to Carbotech XP8s I think), including bedding them in. Let's just say 1mm of wear, you have 10mm worth of usuable pad before needing to replace them. That's ~40 track sessions, or 10 track days.

A set of XP10 pads for stock S2k brakes is ~$190. XP10 pads for the Stoptech ST40 caliper used on the S2k BBK is ~$200, so it's a wash. How much life do guys get out of a set of pads on stock brakes? 5 days? If so, then the pad budget is double that of a BBK.

FWIW, I have no measureable rotor wear after the track day and a few thousand miles of street driving.

 

Pad life is a bitch on stock front brakes. For some reason, the rears last forever, and I have confirmed that they get way hotter than the fronts. I'm not sure on this one...

 

Yup, sliding piston OEM crap calipers flex even when just bleeding the brakes, let alone when stopping a car from speed. Pad life is always limited to uneven pad wear which is much worse on the oem crap.

 

I've had many, many S2000 front rotors crack on me. Never on track, always in the pits after the session.

A few times, however, I have not noticed the crack until I went out on track. That blows a whole session, usually, because by the time you come in and swap rotors, your group is done.

There is only one case I can think of where it is suspected that an S2000 rotor cracked on track. It was that fatality in NJ. In that case, they suspected that one of the rear rotors cracked (and then came apart). [See correction on the next page.]

I've never had a rear rotor crack, and I ran the same rear rotors literally for years. But after that incident I replaced them with new ones -- just in case.

 

the rear rotor definitely get hotter then the front. i've logged rotors temp every track day i have done. usually 20-50 degree hotter than the front.

that's what motivated me to get in touch with RacingBrake to develop a rear vented disk. from the test results i have had so far, the rear brake temp has reduce by half of what the front temp is. and the hat never got over 200 degree, which is very good for the wheel bearings.

MPG will have pre-order group buy setup soon.

https://www.s2ki.com/forums/index.ph...&f=11&t=820202

 

also, Rob Robbinette has gotten 23 track days from the RacingBrake 2-piece OE rotors on his first set.

 

My rotor broke on track at Laguna Seca...it made a big loud pop right by a corner worker station and then they immediately pulled me in for a sound violation...so this whole "won't break on track" business is not accurate at all.

 

Maybe you just didn't notice it in the pits? Either way, only reinforces my stance.

 

I had a rotor crack on the track after pulling out on the track after being in the pits prior to my previous session. It happened after the longest straight and even taking it easy for my warm up lap I bet I was going at least 90mph. It was a very noticeable pop and the brake pedal was instantly pulsing because of the crack.