[Cito]

Once the ice mode engages, what is the best way to mitigate the potentially negative events that might occur thereafter. Does it work to lift and re-engage the pedal?

[rotis]

Completely removing your foot from the pedal and re-applying can reset it, that sure takes a long time though. I think depending on the course, it may be better to just stand on the pedal and wait it out.

[Roostie]

The times when I've had ice mode was on rough pavement. I've gotten pretty bad ice mode braking at the stadium parking lot in San Diego, which is in really rough shape. I haven't had ice mode on road courses or at autocrosses held in parking lots where the pavement was in good shape.
I found that ice mode could be avoided by altering my driving style. By using the brakes like a rheostat dimmer instead of an on/off switch, I was able to prevent ice mode from kicking in.

[Krispy]

Any updated expirences on this topic during the past two years? Has anybody swapped a 2019+ ABS module into a 2017 1LE, did it mitigate?

[Christian1LE]

Wow, this thread is eye opening. I've had an issue with my car twice where I step on the brakes and there is no initial bite, the car doesnt feel like it's slowing down. I was pretty confused as to what it was but I guess this explains it. I've only had it happen twice, and both times where under some sort of trail braking. Here is one I caught on video.

What I experienced was basically no initial brake bite, I thought I thought there was no way I was going to make the corner, but then as the car kind of crested the hill the brakes did a good enough job to slow the car down, but by that time I had already decided to abort the corner. Time stamp should be 13:15 in this video.

[5.M0NSTER]

Originally Posted by Christian1LE

Wow, this thread is eye opening. I've had an issue with my car twice where I step on the brakes and there is no initial bite, the car doesnt feel like it's slowing down. I was pretty confused as to what it was but I guess this explains it. I've only had it happen twice, and both times where under some sort of trail braking. Here is one I caught on video.

What I experienced was basically no initial brake bite, I thought I thought there was no way I was going to make the corner, but then as the car kind of crested the hill the brakes did a good enough job to slow the car down, but by that time I had already decided to abort the corner. Time stamp should be 13:15 in this video.

Ice mode gives you a hard pedal, as the ABS system is closing the inlet valves into the calipers, and pumping out fluid which was already there. You hit the brake pedal and it doesn't move very much, and feels very hard.

If that's not what you experienced, it could be knockback, where the rotor pushes the pistons back into the caliper. Your initial pedal travel is then spent extracting the pistons to make contact with pad/rotor again. I think this is what you may have experienced based on your description.

I have not had Ice mode once on my '18 SS 1LE. The key is in how you apply the bakes. If you have very grabby pads and you tent to jump on the brake pedal, (instead of applying the 20/80 rule and letting the weight transfer forward) your chances of getting ice mode increase.

And of course loose surfaces can also trigger ice mode too.

[Christian1LE]

Originally Posted by 5.M0NSTER

Ice mode gives you a hard pedal, as the ABS system is closing the inlet valves into the calipers, and pumping out fluid which was already there. You hit the brake pedal and it doesn't move very much, and feels very hard.

If that's not what you experienced, it could be knockback, where the rotor pushes the pistons back into the caliper. Your initial pedal travel is then spent extracting the pistons to make contact with pad/rotor again. I think this is what you may have experienced based on your description.

I have not had Ice mode once on my '18 SS 1LE. The key is in how you apply the bakes. If you have very grabby pads and you tent to jump on the brake pedal, (instead of applying the 20/80 rule and letting the weight transfer forward) your chances of getting ice mode increase.

And of course loose surfaces can also trigger ice mode too.

The pedal was hard the entire time, just felt like the ABS wasnt letting the pads grab.

[DaveC113]

Just to be clear, the cause of ice mode is a differential in wheel speed between the right and left sides of the car right after brakes are applied.

It does this because if half the car is on ice and the other half is on pavement a full application of the brakes will cause the car to spin. Typical scenario is the passenger side of the car goes off the road or onto ice that's on the shoulder, driver jams on the brakes, car spins into oncoming traffic. Ice mode is designed to avoid this.

[N Camarolina]

Originally Posted by DaveC113

Just to be clear, the cause of ice mode is a differential in wheel speed between the right and left sides of the car right after brakes are applied.

It does this because if half the car is on ice and the other half is on pavement a full application of the brakes will cause the car to spin. Typical scenario is the passenger side of the car goes off the road or onto ice that's on the shoulder, driver jams on the brakes, car spins into oncoming traffic. Ice mode is designed to avoid this.

His scenario at VIR could fit the parameters for ICE mode activation, couldn't it?.

He had accelerated hard in a less than straight line toward the corner (T11), got on the brakes hard while starting to turn into the apex, which would have meant that the inside wheels were turning at a different rate than the outside wheels. Because there isn't PDR data, I can't tell how abrubtly he transitioned from accel to break, but if he did it rather abruptly, seems like all the ingredients would be there. Add to that the fact that he was using racing pads, which this thread seems to suggest can make ICE mode more likely. And the pedal behavior also sounds like ICE mode.

[5.M0NSTER]

Originally Posted by DaveC113

Just to be clear, the cause of ice mode is a differential in wheel speed between the right and left sides of the car right after brakes are applied.

It does this because if half the car is on ice and the other half is on pavement a full application of the brakes will cause the car to spin. Typical scenario is the passenger side of the car goes off the road or onto ice that's on the shoulder, driver jams on the brakes, car spins into oncoming traffic. Ice mode is designed to avoid this.

Ice mode is there not only for this (split mu condition you desribe), but also for high-to-low transitions, where the car starts braking on asphalt (high mu) and then transitions to braking on ice (low mu). If the brake pressure achieved on high mu were kept, or only slowly decreased wheels would lock and steerability would be lost. Ice mode is not a Camaro specific feature, all cars with ABS have some version of this for the above reasons.

Originally Posted by N Camarolina

His scenario at VIR could fit the parameters for ICE mode activation, couldn't it?.

He had accelerated hard in a less than straight line toward the corner (T11), got on the brakes hard while starting to turn into the apex, which would have meant that the inside wheels were turning at a different rate than the outside wheels. Because there isn't PDR data, I can't tell how abrubtly he transitioned from accel to break, but if he did it rather abruptly, seems like all the ingredients would be there. Add to that the fact that he was using racing pads, which this thread seems to suggest can make ICE mode more likely. And the pedal behavior also sounds like ICE mode.

I don't see a big enough difference in left to right speeds to cause this. If you look earlier in the video, you see lots of lower speed corners while on brakes. There the left to right speed is much higher due to large difference in radius between inside and outside wheels. In the video he started braking more or less in a straight line. Hard pedal indicates ABS experiencing big slip, OR big difference between measured wheel velocities and reference velocity of the vehicle.

[TrackClub]

Never experienced ice mode on either of my 1LEs.
But, i run stock rubber and pads by and large.
I did, however, get ice mode on my old C5Z with near slicks and DSUNO pads. Thank goodness for an escape road at the Glen.

Chris, what rubber and pads are ya on and what track did ya experience it at?

Cheers!

[Christian1LE]

Originally Posted by 5.M0NSTER

Ice mode is there not only for this (split mu condition you desribe), but also for high-to-low transitions, where the car starts braking on asphalt (high mu) and then transitions to braking on ice (low mu). If the brake pressure achieved on high mu were kept, or only slowly decreased wheels would lock and steerability would be lost. Ice mode is not a Camaro specific feature, all cars with ABS have some version of this for the above reasons.



I don't see a big enough difference in left to right speeds to cause this. If you look earlier in the video, you see lots of lower speed corners while on brakes. There the left to right speed is much higher due to large difference in radius between inside and outside wheels. In the video he started braking more or less in a straight line. Hard pedal indicates ABS experiencing big slip, OR big difference between measured wheel velocities and reference velocity of the vehicle.

Yeah dunno, I got no other way to explain it. I've had the exact same feeling before in turn 3. Both turn 11 and turn 3 are the only places on the track where I start hitting the brakes with steering input on the wheel. All the other corners at slower speeds while on the brakes, begin with braking in a straight line for a good amount of time. Could be something else but I don't know what it would be. It's something i'll keep in the back of my mind. I've been to VIR now 7 times and I've only felt it twice, one of those times going off track. So it's certainly not something very common.

[N Camarolina]

Originally Posted by Christian1LE

Yeah dunno, I got no other way to explain it. I've had the exact same feeling before in turn 3. Both turn 11 and turn 3 are the only places on the track where I start hitting the brakes with steering input on the wheel. All the other corners at slower speeds while on the brakes, begin with braking in a straight line for a good amount of time. Could be something else but I don't know what it would be. It's something i'll keep in the back of my mind. I've been to VIR now 7 times and I've only felt it twice, one of those times going off track. So it's certainly not something very common.

I've done about 10 days at VIR and have not yet experienced your problem, including turns 3 and 11. But I can also say I'm not trying to milk every foot by taking the acceleration zone as deep as possible into those two corners and abruptly slamming on the brakes. I get on the brakes smoothly without stabbing and am always aiming to limit pedal travel to be at threshold braking without invoking the ABS. My plan to learn the transition point had been to press hard enough to invoke ABS, then back off enough to make it turn off. Oddly enough, I have trouble detecting when the ABS is active, as it seems much harder to feel the pulsation in the pedal in the 1LE, which is a stark contrast to all the grocery getter vehicles I've owned previously. In the relatively rare instances where ABS does activate, it seems to be while I'm trail braking (at least that's what the PDR data says - I can't feel it in the pedal), though I'm not sure what trips it.

If you are sometimes stabbing at the brake pedal while on track, then I'd suggest you try the suggested fix earlier in this thread for avoiding "ice mode" and smoothly, progressively "squeeze" on the brake instead.

[5.M0NSTER]

Originally Posted by Christian1LE

Yeah dunno, I got no other way to explain it. I've had the exact same feeling before in turn 3. Both turn 11 and turn 3 are the only places on the track where I start hitting the brakes with steering input on the wheel. All the other corners at slower speeds while on the brakes, begin with braking in a straight line for a good amount of time. Could be something else but I don't know what it would be. It's something i'll keep in the back of my mind. I've been to VIR now 7 times and I've only felt it twice, one of those times going off track. So it's certainly not something very common.

I hear you my friend, these systems are tuned for special situations, every day driving, weather extremes, and also track work. Sometimes there are compromises for sure. Sometimes we just have to drive around it.

Originally Posted by N Camarolina

If you are sometimes stabbing at the brake pedal while on track, then I'd suggest you try the suggested fix earlier in this thread for avoiding "ice mode" and smoothly, progressively "squeeze" on the brake instead.

I do think this is key. If you let the weight transfer, ABS has less to do since you're less likely to lock wheels. And as you mentioned, when ABS stays out of your way, you don't even notice it's there.