village idiot

A number of us were wondering why the hard brake pedal mode ("ice mode" as its been called ) is active in PTM, especially sport 2 and race. It seems like it activates when a wheel is suddenly or quickly locked, like it would on ice or other low friction surface. Unfortunately, a wheel locking quickly happens a lot on the track because, generally, one or more tires are unloaded at any given time, plus things like bumps and curbing unload them.

A combination of being unloaded with big brakes and track brake pads seems to engage this "ice mode" on the track, where it's difficult to see the benefit of it. So what is this "ice mode" and why is active in PTM? It seems very dangerous.

village idiot

yay, got picked to get voted on.

fleming23

I hope we get some sort of helpful answer, but expect it will be a corporate response. This **** has sent me off track a couple times, and is the most frustrating part of driving competitively. At some point, someone is going to get hurt when they go to stop and the brake pedal goes rock hard not allowing them to stop as expected.

village idiot

I started braking 100ft back when I know it's bumpy and backing up 50ft just because of this.

I also started braking more progressively, like I do in non ABS cars.

ponderingtom

Thank you, Village idiot, for posting this question. I'm still new to the board and didn't know about the Ask Tadge group. Love it!

I have video from an autocross I went to last weekend where 1 out of 8 runs, I had the issue. Almost blew through the cones after the finish lights. The telemetry on the PDR video shows I was at about 60% braking when I was actually standing on the pedal trying to get it to stop. The other 7 runs, it also showed about 60%, but it stopped in about half the distance and I was truly applying about 60% force on the pedal.

We gotta get a solution to this!

tw78911sc

Not just a Corvette issue, I had it happen to me at Watkins and VIR in a 15 Camaro SS 1LE. It happened to me in my 07 Z06 at NCRR at over 150 mph into a 35mph tight U turn and I was ready to write it off, luckily it did slow enough to late entry the corner, I had no time to start manually pumping pedals Only happened 1x at the same track. You loose confidence like others said and you start backing up braking points. I've heard a lot of spec racers are approved to use a cheap BMW ABS unit that is a plug in.

village idiot

Dane@LGmotorsports

Sounds like a project for us.

village idiot

CorvetteBrent

Yes, go for it!

LagunaSecaZ06

I have 2016 Z06/Z07 that I switched Girodiscs and ST43 on to it. At Laguna Seca a few days ago I was getting ice mode going into turn 2 (front straight leading to the hair pin) and going into Turn 8 (90* hard left into the corkscrew). In both of these places I was concerned about going off track. When I pitted after my session, my rotors were about 400*. A C6 Z06 that was in my group, his rotors were about 800* in the pits. I think the ice mode was limiting my braking pressure and hence rotor temperature. If was getting brake fade, I would think that my rotors would be over 800* and smoking. My rotors look great with no pad deposits. I am going to call Girodisc on Monday for their recommendation. With CCB's my car was a monster at Laguna Seca, I would brake really late and have complete confidence (the pedal never got really hard either).

jvp

Quick note: GM's been on a 2-week summer vacation, so this question has to wait. We should see an answer out of Tadge in the coming weeks when he gets back into the office. Stand by.

village idiot

Thanks for the update. Any ETA?