tmak26b

I have been a big fan of the C6 since I got it. One of the thing I don't like is the way the brakes are. For one, the brake setup is very front bias, lock up is way too common if you push the car hard. Also another problem I have is that the car has the tendency to get into ice mode on the ABS upon hard braking. It doesnt matter if I brake straight or not, ice mode just keeps kicking on if i get on the brakes hard. Do you guys know what are the ways to avoid it? Do I have to slowly apply the brakes?

errance

Sorry, what is ice mode?

AU N EGL

Turn off your AH/TC. Not even comp mode.

Few other questions:

You runing the stock brake set up?

if so what pads,
What brake fluid

what front tires are you running. size, and age

If not stock brake set up then what are you using?

tmak26b

I have kicked ice mode on with my street and race tires with stock or race pads, sometimes you can kick it without even locking hte brakes up. It's scary when you are coming down the straight, you nail the brakes and the ABS would just make noise and not slow the car down.

AU N EGL

That may be your brake pads have glazed over and or boiling your brake fluid.

I had that happen one in my C5, turns out I boiled ATE super blue brake fluid and the car would not stop. Off the end of the VIR #1 at 135 mph.


Which brake pads, and how much use have they had?

Plus which brake fluid and when did you last change the brake fluid?

gkmccready

I've never had that issue with my '06 Z51. The only thing even close is if it's a cool morning out and I was too lazy to take the race pads off the car. Are you really seeing "Ice Mode" displayed on the DIC?

I squeeze the brakes on, I don't stomp them to the floorboards...

davidfarmer

In probably hundreds and hundreds of laps, I've had "ice mode" problems once. I was off line (late pass) going into turn one at VIR. I entered the braking at a diagonal angle.

I didn't brake too late, but the ripples in the pavment (compression from repeated braking, like tire grooves on the interstate) were at a strange angle, and I guess the car couldn't handle it. I could tell immediately that the brakes were not going to stop the car, so I modulated, drove straight off in a controlled manner, cruised around the bend and drove back on track.

Again it was rare and I've only seen it once. I don't think the DIC actually said Ice mode, but it was exactly the same as when I actually drove a Vette on Ice once. The ABS basically just gives up (the little valves can only "give" so far) and assumes you are on a surface with zero grip.

tmak26b

What you are talking about is completely different than what I experienced. When ABS kicks into ice mode, it will cycle on and off at its own leisure pace. Therefore the car does not get the necessary braking power to stop. You will know when it hits because you will feel the car keep going yet the brakes are cycling on and off (rather slowly I might add).

Overheated pads and brake fluid will just drop your pedal, ice mode will keep your pedal nice and stiff except the car just won't stop. Even if you let it off and get back on, you might or might not be able to get the car out of it. I think the car needs a sec or so to "reset" or relax. Of course the driver also has to recover from the oh $hit moment.

davidfarmer

I agree with you tmak26b, it's just VERY RARE in my experience. Even in my early years in F-bodys, C4's, and C5's, it only happened on rare occasion. The system is usually very good at dealing with a variety of conditions and surfaces.

autoxer6

Ice mode is more common in autocross where trail brakeing is used more. My experience has been that it isn't about how hard you hit the brakes, it's how much you are turning when you are on them hard.

tmak26b

That's what I used to think too, but both times it did it on me was during hard braking. Heck as soon as I stepped on it, ice mode kicked

AU N EGL

That is exactly what happened when I boiled ATE Super Blue brake fluid and glazed over PFC01 brake pads. Everything was over heated. Brake peddle would not move more then 1/4" and the car would not stop.

And why I keep asking what brake fluid, when was the brake fluid last changed and what brake pads were you using?

rbl

If the brakes work OK otherwise then you probably have a bad wheel sensor. Assuming you are running reasonable rubber.

Boiled fluid and glazed pads won't do it. I have some experience with the C6 and have never seen this issue in any of the cars. The stock C6 brakes are very good.

You made another comment that you don't like the bias (which is PDG stock) and that lock up is way too common if you push the car hard. I've not seen this issue either. I can stand on the brakes at 130 MPH and I can not lock up the front going into the corner on a good surface (they also slow the car ... lol).

I think you have an ABS issue/sensor and it may be time to have it looked at.

tmak26b

ABS dont pulsate when you glaze or overheat your brakes. In ice mode, it does.

AU N EGL

Does that mean you dont want to look at 'other' possibilities of what may have happened?

Mine sure pulsed like hell, and still did not stop. Granted the C5 and C6 systems are different.

Just for grins,

What brake fluid were you using?
when did you last change the brake fluid?
what brake pads were you using?

codename Bil Doe

It'll put you into ice mode if you load up the yaw sensor before getting into the brakes. This is much more common and easier to do in autox than in rr.

For example, If you're coming out of a high-speed slalom and the car is still loaded while approaching a slow left-hander, the yaw sensor assumes it's still in a corner and dangerous to brake or else you'll fly off the road and die. It activates the ice mode because assumes it knows what's better for you than you do. For 90% of everyday corvette drivers that's probably true..

Even light brake application while the yaw sensor is loaded will cause ice brakes. Very simple to recreate on the street without going 10/10th's. Carry decent speed into a turn so the yaw sensor gets loaded and lightly touch the brake. You'll feel ice mode pulsate the pedal as if you were instantly entering ABS.

This WILL occur even if you turn off TC & AH. You can't completely disable the yaw sensor and it's affects on abs.

larryfs

I felt ice mode a few times in my C4, or at least what I think is ICE mode. The brake pedal just starts pulsating wildly.
This is at Pocono North just before the main straight, the track surface is terrible, and loaded with small mineute bumps. It's like the ABS freaks out. It's very repeatable at this one spot on the track.

I have never felt it otherwise.

rbl

This is the 14th issue you've had with this car dating back to October 07, including this issue. It's time to get rid of the car as it is obviously a lemon.

tmak26b

Perhaps, but I wouldn't say too much if you can't tell the difference between a mechanical error vs. a design (a bad one that is).

As I stated earlier, the issue is not with pads or fluid overheating. I can't overheat my pads and tires during the first 10 sec. of an autox run. This is an issue with an overly sensitive ABS computer, which one of the poster was right on about the yaw sensor. Still, I experienced the same thing twice under hard threshold braking. I think I might have just nailed the brakes too hard and the computer flipped out when I did it. I think a local racer here experienced the same problem on his C5, let see what his take is on it. Ice mode definitely exist, some of you just have never experienced it. Ice mode should be in most cars, it's just really sensitive on the Vette and it takes a lot longer to reset.

FYI..It did it on stock and race pads, Motul RBF fluid. Trust me, they are not boiling. I experienced boiling way too often with my last car.

tmak26b

That's probably just ABS working, which the bumps caused. In ice mode, the pedal will not pulsate repeatedly like a normal ABS stop. It will pulsate at a much slower rate. (THAT MEANS NOT MUCH BRAKING AHHH)

Yes, I know the bumps you are talking about at Pocono North. I nailed them a few times hard and the ABS flipped on me too in my old car.