willys46

Took my 2002 Z06 to an autocross.
Made my first run with traction control and active handling turned off.
One quick push of the active handling button. Course had a long straight with a hairpin at the end. Had to hit the brakes hard to get speed down for the turn. Made a decent run with great braking. Second run I put it in competitive driving mode. Accelerated down the straight and again hit the brakes hard. Decent pedal but no braking!! No ABS pulsing , no wheel lock up. missed the turn completely!. Had normal braking on way back to the pits. Third run I hit the active handling button once to turn off both Traction Control and Active Handling . Hard braking activated ABS normally.
I thought the active handling button didn't affect braking at all.
ABS is always on regardless of active handling setting.

Has anyone else experienced problems with hard braking in competitive driving mode?

Thanks for your help,

Art

Vetteman Jack

Moved to Autocross/Roadracing Section.

Acid666

I've had problems with competitive mode and braking a few times when I was learning the car. My hard braking to set up my turn in caused it to kind of act weird because I turned with too much brake and the yaw control kind of kicked in to keep the car straight. That was only on a few instances because I rarely brake that hard into a turn (I learned to finally start doing all my braking before the turn but adding a little bit of trail braking to give the front of the car a little more bite on turn-in).

I had more problems with competitive mode kicking in on coming out of high speed turns with a lot of acceleration and G-forces where the car was pulling with the Gs and the rpms got limited to keep the car straight.



Not sure of your experience, but I'd highly recommend driving the car in comp mode just for a little bit until you finally start to get it to correct the car enough to where it starts to hinder your progression, and then start running with all of the nannies turned completely off. Took me a good half a season to get to that point but it really helped me learn when I wasn't pushing the car enough. Once I climbed that mountain I stopped racing in comp mode.

Bill Dearborn

Comp mode doesn't have anything to do with ABS. Yes, active handling will pulse the brakes at one wheel or the other to yaw the car in the direction you turn the steering wheel if the car isn't yawing properly to achieve what you want to do. However, if you are on the brakes hard enough to lock up the wheels ABS will pulse the brakes the way it wants to keep the wheels from locking up.

Were you getting any twisting of the car in one direction or the other when you applied the brakes, as that can cause AH to activate?

It sounds more like you got into something called ICE Mode where the ABS system is fooled into thinking the wheels are in incipient lock up when they aren't. Then you get a hard pedal but no stopping. The solution is supposed to be lift the foot off the brake pedal and put it back down again.

Bill

tw78911sc

I've heard a lot of race cars are using a BMW ABS module and have much better braking control. I had the same issue with a 2015 Camaro 1LE. It is a GM thing, not just Corvette.

Justin Barbry

Sounds more like ice mode than any other problem. It's easy to overpower the front tires if you jump on the brakes to aggressively.

YEGC5Z06

My 02 Z06 does the same thing in competition mode, seems to be a feature of these cars. The explanation I was told, was that the system almost needs a short "cool off" period after it's been active. It is not very confidence inspiring, to the point that I had to do a "pre-pump" of the brake pedal before the braking zone.

Olitho

None of these problems sound normal in my experience. I have 40,000 track/racing miles on my 2002 C5 Z06 chassis and the car is one of the best stopping cars in my races.

I never get ice mode and I never get any aberrant behavior unless it is the rare complete failure of the ABS system due to a connector problem or similar. It either works great, or it doesn't function at all.

I suspect some other problems with your cars or an external factor inducing a problem, but like I said, dry or wet mine has always worked most excellently.

Olitho

PS. I have my stability control completely disabled in my car.

Justin Barbry

Tires and brake compound matter a lot here. Surface conditions also play a role. If you are on something less than 200tw or have less aggressive pads then you may never experience it. I've had it happen three times with Re71rs and Ferrodo DS2500 pads. All three times were a combination of 200tw tires, aggressive pads, and a slight surface irregularity in the braking zone. I've switched to G-Loc pads with less initial bite and haven't had an issue since.

eric1855

sounds like ABS ice mode to me too

Happens often at AutoX regardless of competition mode on or off, its unrelated.

If you autox with competition mode on, you need to keep an eye on your rear brakes, it will overheat them with a quickness

C5 Hardtop

It does not sound like the cause is a Competitive Mode fault. I'd look closer at the braking system starting after the tire and work back to the pedal. Like overheated brakes coincidentally occurred when you were changing A/H modes, but that is just a guess. The car should go into ABS mode on demand with any A/H mode including off. There wasn't any wheel slip detected when you went off so it makes sense the ABS didn't get enabled. Since the problem was repeatable, you should be able to narrow down the issue.