I would definitely take a look at the Axle Nut TSB first and take it from there. My mechanic told me that he had to torque the axle nuts on many S2000s since it's pretty common. Prior to that I was scratching my head to figure out what's really going on and ordered a 05 brake booster and MBC. After I explained the symptoms and mention the fact it only happens in track environment he advised me to do the TSB first and I am glad he did

I also owned a Miata but didn't get a chance to track it. I haven't been to PR for a long while (although I love the track and configuration, I find that track a bit dangerous since not a lot of run off area) but RMP and ORP is a lot of fun especially with this car. I am travelling to ORP today for a weekend club event(I am a club member) and will probably go back there on September. I have some 50% off vouchers for guests if you're interested

 

Sorry, can't help resolve your issue, but you've now explained something I experienced this season. Previously I was running on old brake fluid and my brake pads/rotors were pretty low in life, so my brakes sucked. This year I installed Ferodo pads and RE71s and I definitely experienced this phenomenon several times. It caused me to blow through a Chicago box the first time it happened. That was after an elevation transition, so that's probably what caused it for me.

 

interesting. I have been autocrossing my 07 S for about 5 years at several different sites on stock brake pads and have never experienced ice mode. My pads are close to needing replaced and I was thinking about the AX6 pads. Now I will have to think about going with stock pads.

 

Ice mode is when the ABS thinks that you're on ice and reduces the braking power (hence the word "ice"),
it typically happens when the aggressive pads (more aggressive than the tires) so you shouldn't see that becoming an issue with OEM pads or any other street pads.

Matching the pads with proper tires is really important at this point: less aggressive pads with more aggressive tires will typically result in cooked pads/brake fluid and/or brake fade, and more aggressive pads with less aggressive tires should trigger ICe mode..hope that helps

 

I have Hoosiers R7 and PFC11.
Shouldn't ABS just pulse when you are on ice?

 

Depends on the ABS system and even with the same system ABS tuning might be different, Race ABS systems have a lot higher tolerances than the street ABSs also ..IIRC, some Corvette models come with more aggressive tuned ABS since it comes with Carbon Ceramic brakes and Cup 2 tires (like Z07 packaged Z06 vs regular Z06)

I highly doubt that is ("Ice Mode") what you're experiencing with the tire/pad combo you stated above. It's somewhat hard to distinguish the Ice mode from the other brake issues also since the symptoms may be the same for other issues as well. I recently learned that if the brake force is considerably less, especially at the track environment, "pad knock back" issue would be the first place to look at, since pads are pulled back after each hard corner, causing a delayed reaction (lack of brake force that requires you to double tap the pedal on the next corner/hard brake zone... double tapping the brake pad helps but it costs you lap times .. "if the booster or mbc was the issue, we would expect to see it on the road too" he said and it makes sense

 

My brake gets hard as rock, don't need to double tap it. Just keep pushing but I think it is actually car slowing down to the point it works again by itself.

 

thanks for your response glamcem. So I guess the best thing for me (RE-71s and potentially AX-6 pads would be to call the manufacturer for advice. I was contemplating AX-6s on front and back.

 

Do you mean it feels like there is no "boost" ? it sounds like you may have a problem with the brake booster or vacuum leak somewhere.

Ice mode, OTOH, is the opposite of what you're describing; it happens when there is too much initial bite and brake force -with brake boost of course- that make the ABS to think there is no traction and the car is on the 'ice'.. no wonder it's pretty common on Corvettes which have gigantic brake boosters (compared to many other cars) that provides tons of braking force ..

 

you're welcome.. Have you ever considered the Raybestos pads? specifically ST43s?

both my friends and I tried Carbotech pads and we all ended up going back to Raybestos pads (St43 or ST47).. no wonder why it is the choice of pad of many racers and track junkies I've run into they last forever, priced similarly, a lot better initial bite, and even with better operating temps and they are less harsh on the rotors and fade is non-existent .. I've been using them on the street also with no issues, since ST43s don't require really high operating temps..they're little bit noisy but not screaming

I also have been tracking with RE71Rs matched with ST43s (I have stoptech BBK up front FYI), I will try ST47 front / ST45 Rear combo when I need a replacement

here's a link for the detailed spec charts
Raybestos racing pad charts