[khcoaching]

I decided to start a separate thread on this, mainly to add and comment on the data and not clog up the other post.

I looked at pretty much all of my laps the last 6 months via AIM, trying to find laps where I encountered ice mode. From there, I looked at other parameters, throttle, wheels speeds, brake application point, initial brake input, etc.

Honestly, not a lot of answers. Yes, it happens mainly when braking later than I normally do, but once was actually earlier and a deep look at the initial brake application shows no difference between the laps. Lap to lap, the inputs look identical.

So, on to data. (I'm going to put all the graphs in here full size)

For reference - 2021 SS 1LE - 1LE front calipers, stainless lines, DOT4, Ferodo 3.12 and Cobalt XR1 pads (both used) DSSV conversion, Goodyear 3R and Hankook Z214 tires


1) 2 laps, same lap time showing what ice mode looks on data -



2) ALL the laps in a single run -



3) T8 at The Ridge. Holy Crap, near 3000psi and note, the car isn't slowing down any more than the other graph with less psi.



4) T11 at The Ridge. Note, nothing different than the previous lap



5) T13 at The Ridge. This is #1 blown up. 3300psi and the car isn't slowing down. Yes, later brake application, but same initial input. Ice mode was in full effect for about 210'.



6) I looked at wheel speeds from every wheel, comparing it to a know good lap...All the same and one wheel doesn't drop off more than the other, indicating no lock up or ABS intervention.



Not sure the answers anything, but for me, it still points to tires not having the grip for what there brakes can do.

Ken

[Christian1LE]

If anything it seems to me that the more grip a tire has the more likely ice mode is activated. When I say "Ice mode" I'm simply describing a hard pedal with no strong initial bite, feels like the car won't stop but it inevitably does, just a bit of a longer braking zone.

I got what I believe is ice mode several times at my last track day. It very rarely has happened in the past. The only difference this time was that I was on slick tires and I'm using missmatched front/back pads. I have DTC 60's in the front and XP12's in the rear. I've used this for about 6 trackdays now with 0 issues on my OEM tires. The only difference this time around was warmer temperatures and slick tires (R7).

[khcoaching]

Originally Posted by Christian1LE

If anything it seems to me that the more grip a tire has the more likely ice mode is activated. When I say "Ice mode" I'm simply describing a hard pedal with no strong initial bite, feels like the car won't stop but it inevitably does, just a bit of a longer braking zone.

I got what I believe is ice mode several times at my last track day. It very rarely has happened in the past. The only difference this time was that I was on slick tires and I'm using missmatched front/back pads. I have DTC 60's in the front and XP12's in the rear. I've used this for about 6 trackdays now with 0 issues on my OEM tires. The only difference this time around was warmer temperatures and slick tires (R7).

Interesting! Thanks for the unit.

Ice Mode IME, has been after initial brake input, essentially where the data shows. I am using the stock SLE rear brake system with much less robust pad than the fronts. RE - the square v stagger...I understand the why it could be an issue over stock, but I was actually braking - later - with my 3S square setup and never had an issue, same with the Toyo RRs. I only started having the issue with the 3Rs and when I went to -3.7 front camber. The one time it happened with my Z214s was in a corner that drops away under maximum braking and almost any car can get it there, so I am giving there Z214s a pass there.

Ken

[DaveC113]

The more you deviate from OEM in terms of tire grip, size, differences in brake pads front to rear, the more wheel speeds side to side and/or front to back will deviate from what the EBCM expects to see and the more likely you are to see ice mode.

[GunMetalGrey]

Originally Posted by Christian1LE

If anything it seems to me that the more grip a tire has the more likely ice mode is activated. When I say "Ice mode" I'm simply describing a hard pedal with no strong initial bite, feels like the car won't stop but it inevitably does, just a bit of a longer braking zone.

I got what I believe is ice mode several times at my last track day. It very rarely has happened in the past. The only difference this time was that I was on slick tires and I'm using missmatched front/back pads. I have DTC 60's in the front and XP12's in the rear. I've used this for about 6 trackdays now with 0 issues on my OEM tires. The only difference this time around was warmer temperatures and slick tires (R7).

Interesting! I thought more grip in the tires would have exactly the opposite effect because there would be less slippage/ABS and hence misreading as ice...

What else changed with your new set up? Your driving style? More aggressive?

Originally Posted by DaveC113

The more you deviate from OEM in terms of tire grip, size, differences in brake pads front to rear, the more wheel speeds side to side and/or front to back will deviate from what the EBCM expects to see and the more likely you are to see ice mode.

I read something on the Corvette forum that seems to make sense; with stickier pads the car locks up the tires more easily with less brake effort, hence the system thinks you are on ice... however this does not seem to make sense with stickier tires. Can you elaborate on why the change alone would cause more ice mode when both the brake and tires increase in grip?

[GunMetalGrey]

Originally Posted by khcoaching

Interesting! Thanks for the unit.

Ice Mode IME, has been after initial brake input, essentially where the data shows. I am using the stock SLE rear brake system with much less robust pad than the fronts. RE - the square v stagger...I understand the why it could be an issue over stock, but I was actually braking - later - with my 3S square setup and never had an issue, same with the Toyo RRs. I only started having the issue with the 3Rs and when I went to -3.7 front camber. The one time it happened with my Z214s was in a corner that drops away under maximum braking and almost any car can get it there, so I am giving there Z214s a pass there.

Ken

I have experienced ice mode both part way through braking zone, see first video the car starts slowing down quickly then decides not too as soon as I start my turn in, like you said happened the only time with your slicks




And I have experienced it right away immediately upon hitting the brakes like in this video where it only decided to slow down right at the very end right before hitting the dirt bank

[GunMetalGrey]

Originally Posted by khcoaching

I decided to start a separate thread on this, mainly to add and comment on the data and not clog up the other post.

Ken

Thanks for doing this Ken.

I can't tell from your data, but compared to my vids, my experience seems to be more severe than what you described your ice mode experience to be, but please correct me if I am wrong.

Not sure if that's because I had the older 2018 EBCM ABS Brake Module calibration vs your newer 2019+ EBCM ABS Brake Module calibration?

Most of the time I've experienced ice mode it has been severe, but one time it was mild and barely noticed it, thought the brakes were fading due to heat...

[RoaringV8]

I had a track day this weekend on a new setup (to me) with camber plates up front a -3.5 camber and SC3R's on 305/19's. I noticed what I thought to be more ICE mode than I've ever experienced. That being said, I'm wondering if I was experiencing more of a "pad knock back" instead. I started having to do more pumping up the brake pedal after long straights into heavier braking turns and that really seemed to help the issue quite a bit. Maybe I haven't been experiencing ICE mode like the rest, but wondering if folks are pumping the brake pedal before some of the larger braking zones to see if that helps.

[Canyonero]

If one experiences ice mode, is there a best approach to correct it? Push harder, pump the brakes etc...?

[GunMetalGrey]

Originally Posted by Canyonero

If one experiences ice mode, is there a best approach to correct it? Push harder, pump the brakes etc...?

Good question

[khcoaching]

Originally Posted by GunMetalGrey

Thanks for doing this Ken.

I can't tell from your data, but compared to my vids, my experience seems to be more severe than what you described your ice mode experience to be, but please correct me if I am wrong.

Not sure if that's because I had the older 2018 EBCM ABS Brake Module calibration vs your newer 2019+ EBCM ABS Brake Module calibration?

Most of the time I've experienced ice mode it has been severe, but one time it was mild and barely noticed it, thought the brakes were fading due to heat...

HA! Mine was pretty severe..I was looking at what I was going to plow into.

Ken

[khcoaching]

Originally Posted by Canyonero

If one experiences ice mode, is there a best approach to correct it? Push harder, pump the brakes etc...?

Yeah, this is tough. The system needs to reset and the only way that happens is to release the brake and try again, the opposite of what your brain is screaming. Pushing harder only makes it worse.

Ken

[Christian1LE]

Originally Posted by GunMetalGrey

Interesting! I thought more grip in the tires would have exactly the opposite effect because there would be less slippage/ABS and hence misreading as ice...

What else changed with your new set up? Your driving style? More aggressive?



I read something on the Corvette forum that seems to make sense; with stickier pads the car locks up the tires more easily with less brake effort, hence the system thinks you are on ice... however this does not seem to make sense with stickier tires. Can you elaborate on why the change alone would cause more ice mode when both the brake and tires increase in grip?

The slicks were 315/30/18 so they are slightly smaller diameter than OEM. Driving exactly the same every lap. I'm going to be at VIR this weekend for hyperfest and I'm going to keep a close eye on it to see if I can completely eliminate it by braking slightly less aggressive on initial pedal input. I also ordered DTC 60's for the rear to see if that helps the issue at all.

[GunMetalGrey]

Originally Posted by khcoaching

HA! Mine was pretty severe..I was looking at what I was going to plow into.

Ken

Oh ok haha well that's no good!

Perhaps the new ABS Brake Modules don't make much of a difference at all then...