Ice Mode...who has experienced it ?????
09-05-2018, 07:02 PM
#1
Melting Slicks
Thread Starter
Ice Mode...who has experienced it ?????
Some of you may have seen my earlier post/thread on this.....
https://www.corvetteforum.com/forums...my-brakes.html
Just to recap....
We autocross... a LOT !!!!... 20-25 events each year... 2 drivers... and we do between 6 and 15 runs each per event.
2016 Z06 A8 Stock with DSC Alignment, and running Continental ExtremeContactSports for rain .
I also have BFG Rivals (315 and 335) on 18x11 and 18x12.5 for dry/warm.
We acquired the car last November, and started autocrossing it this year in March.
We did 8 events from March through May.
I wanted "better" brake pads, so I installed some G-Loc May 31.
After that, I started experiencing "Ice Mode"... several times during the day.
And my wife experienced it too.. but not as often as me (I guess I'm more aggressive).
So I posted in that post/thread I mentioned earlier.
People said to brake a little bit sooner, and not so hard initially.
(Strange I should have to do this now after autocrossing in 10 different Corvettes over 38 years).
So I HAVE been somewhat less aggressive (I think).
We did 4 events in June, and I was not happy with these brake pads. (That's another story)
So I installed some Ferodo DS2500 pads.
July and August we have done 7 events.
Still experiencing it.
2 events ago, another VERY experienced driver also made a couple of runs.
He is an AWESOME driver... 1990 ZR1 and he still can do better than most (all ??) of us.
He also experienced it... and blew through the stop box.
Just this past Monday we had a "fun day"... a couple got married and had the wedding out at the
race pad, and invited a whole bunch of us to lay out a course, bring our cars, and race, and
take "others" (other guests) to ride along.
So that day 5 of us (all very experienced autocrossers... some national champions), all drove the car.
We ALL experienced "Ice mode". No-one can tell me we are ALL too aggressive in our braking.
My wife and I did at least 20 runs each... the other 3 did 3 to 6 runs each.
So after some discussion, and some review of when this all started, I have decided to replace the brake pads
with my OEM pads. I did this today. We have 4 more events this year....
Sept 16, 23, 30, and Oct 13.
I'll report any changes, differences, or whatever.
Something to think about, maybe ?????
https://www.corvetteforum.com/forums...my-brakes.html
Just to recap....
We autocross... a LOT !!!!... 20-25 events each year... 2 drivers... and we do between 6 and 15 runs each per event.
2016 Z06 A8 Stock with DSC Alignment, and running Continental ExtremeContactSports for rain .
I also have BFG Rivals (315 and 335) on 18x11 and 18x12.5 for dry/warm.
We acquired the car last November, and started autocrossing it this year in March.
We did 8 events from March through May.
I wanted "better" brake pads, so I installed some G-Loc May 31.
After that, I started experiencing "Ice Mode"... several times during the day.
And my wife experienced it too.. but not as often as me (I guess I'm more aggressive).
So I posted in that post/thread I mentioned earlier.
People said to brake a little bit sooner, and not so hard initially.
(Strange I should have to do this now after autocrossing in 10 different Corvettes over 38 years).
So I HAVE been somewhat less aggressive (I think).
We did 4 events in June, and I was not happy with these brake pads. (That's another story)
So I installed some Ferodo DS2500 pads.
July and August we have done 7 events.
Still experiencing it.
2 events ago, another VERY experienced driver also made a couple of runs.
He is an AWESOME driver... 1990 ZR1 and he still can do better than most (all ??) of us.
He also experienced it... and blew through the stop box.
Just this past Monday we had a "fun day"... a couple got married and had the wedding out at the
race pad, and invited a whole bunch of us to lay out a course, bring our cars, and race, and
take "others" (other guests) to ride along.
So that day 5 of us (all very experienced autocrossers... some national champions), all drove the car.
We ALL experienced "Ice mode". No-one can tell me we are ALL too aggressive in our braking.
My wife and I did at least 20 runs each... the other 3 did 3 to 6 runs each.
So after some discussion, and some review of when this all started, I have decided to replace the brake pads
with my OEM pads. I did this today. We have 4 more events this year....
Sept 16, 23, 30, and Oct 13.
I'll report any changes, differences, or whatever.
Something to think about, maybe ?????
Last edited by NTMD8R; 09-05-2018 at 07:05 PM.
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Mikec7z (09-09-2018)
09-05-2018, 10:13 PM
#3
Safety Car
I still don't fully understand what "ice mode" is. I presume it is when you have consecutive hard brake applications and the second application gives you a hard peddle but no hydraulic pressure so no braking. But how close in time do the applications have to be to experience it? A 15 second time spread? A 10 second time spread? A 5 second time spread? A less than 3 second time spread? Is it caused by the ABS system? Is it caused by the piston in the hydraulic cylinder not having time to cycle properly so you are back at full hydraulic pressure? Everybody just complains about "ice mode" with no analysis of the root cause. I would guess that autox would show "ice mode" much more often than HPDE or road racing as the turns are so much closer together. In fact in some situations as you know the brake applications are very close together in time. Say an offset box or Chicago box.
If it is caused by the ABS system, can pulling the ABS fuse defeat the ABS so that you can try good old threshold braking to see if that keeps you out of the "ice mode?" Quite obviously there are a number of people very successfully autoxing cars without ABS. In my race car, the class rules were that ABS had to be removed or if you didn't want to lose the weight you could simply pull the ABS fuse. It took a bit but soon we all learned how to threshold brake just fine. That is one solution if it is the ABS system. If it is the hydraulic cylinder piston that is a horse of a different color, particularly if you are running a class that allows no modification to the oem hydraulic cylinder. Prior to going road racing I autocrossed competitively for several years with some seriousness (52 weekends autocrossing by driving all over the West in my rookie year). In those days the problem was the master cylinder piston time cycle. And there was nothing we could do in my class (FS). So we had to learn to drive around the problem. At that time the master cylinder piston took about 3 seconds to cycle and rebuild full hydraulic pressure. So you simply had to know that you weren't going to get to full brake pressure applications in less than 3 seconds. So you generally had to overbrake on the first of 2 consecutive braking segments so that you could make the second turn without problem.
Once you identify the source of the problem you will be able to figure out a solution. My reading of Tadge's answer is that it is in the ABS programming. If that is the case, what is the best way to defeat ABS in a C7?
BTW, my lesson for learning threshold braking was in my first road race. It was at AutoClub Speedway and was braking from 150 to 65 into Turn 3 in the morning warm up session on a set of brand new race tires. I flat spotted the fronts so bad I darned near lost my teeth running the rest of the weekend on those tires. They must have been near square from that flat spotting and running the roval with square tires was a bit bumpy. But it was a good enough lesson that I generally could max brake after that without tire smoke appearing.
If it is caused by the ABS system, can pulling the ABS fuse defeat the ABS so that you can try good old threshold braking to see if that keeps you out of the "ice mode?" Quite obviously there are a number of people very successfully autoxing cars without ABS. In my race car, the class rules were that ABS had to be removed or if you didn't want to lose the weight you could simply pull the ABS fuse. It took a bit but soon we all learned how to threshold brake just fine. That is one solution if it is the ABS system. If it is the hydraulic cylinder piston that is a horse of a different color, particularly if you are running a class that allows no modification to the oem hydraulic cylinder. Prior to going road racing I autocrossed competitively for several years with some seriousness (52 weekends autocrossing by driving all over the West in my rookie year). In those days the problem was the master cylinder piston time cycle. And there was nothing we could do in my class (FS). So we had to learn to drive around the problem. At that time the master cylinder piston took about 3 seconds to cycle and rebuild full hydraulic pressure. So you simply had to know that you weren't going to get to full brake pressure applications in less than 3 seconds. So you generally had to overbrake on the first of 2 consecutive braking segments so that you could make the second turn without problem.
Once you identify the source of the problem you will be able to figure out a solution. My reading of Tadge's answer is that it is in the ABS programming. If that is the case, what is the best way to defeat ABS in a C7?
BTW, my lesson for learning threshold braking was in my first road race. It was at AutoClub Speedway and was braking from 150 to 65 into Turn 3 in the morning warm up session on a set of brand new race tires. I flat spotted the fronts so bad I darned near lost my teeth running the rest of the weekend on those tires. They must have been near square from that flat spotting and running the roval with square tires was a bit bumpy. But it was a good enough lesson that I generally could max brake after that without tire smoke appearing.
Last edited by pkincy; 09-05-2018 at 10:16 PM.
09-05-2018, 10:32 PM
#4
no idea if i am correct, but is it possible that the tires are spinning around the rim, and the rim is stopping from the hard braking?
I know aftermarket rim companies add "knurling" to the inside of the rim where the tire sits/mounts to the rim itself, to prevent this from occurring.
My second guess would be if your brake fluid is boiling.
I have had it happen on my stock vehicle with stock metal brakes (non ceramic) and i have assumed either my brake fluid boiled, or the tires were spinning around the rim itself once they get warmed up and grip the road well, when i brake very hard.
I know aftermarket rim companies add "knurling" to the inside of the rim where the tire sits/mounts to the rim itself, to prevent this from occurring.
My second guess would be if your brake fluid is boiling.
I have had it happen on my stock vehicle with stock metal brakes (non ceramic) and i have assumed either my brake fluid boiled, or the tires were spinning around the rim itself once they get warmed up and grip the road well, when i brake very hard.
Last edited by Mikec7z; 09-05-2018 at 10:37 PM.
09-05-2018, 10:34 PM
#5
Melting Slicks
Thread Starter
Typically, in autocross, you drive through some element (slalom, sweeping turn, etc.), then accelerate
towards the next element. You then brake as much as necessary for that element, etc., etc.
But when "ice mode" happens, the brakes do NOT engage, and the car continues at the speed you are
trying to slow down from. So to address this (when it happens), you must lift off the brake,
and then apply again... but just a bit more slowly. It should then engage and you can then apply
much more pressure. There have been several times when this has NOT worked for me,
and I had to retry again... all this while barrelling down at a speed I do not want to be at,
and heading for pylons I do not want to hit. (pucker factor rears a very ugly head here).
This is what we are now having to do.
Threshold braking and or braking sooner involves applying the brakes sooner and only enough so they then engage
so you can then apply as much pressure as needed for this element.
towards the next element. You then brake as much as necessary for that element, etc., etc.
But when "ice mode" happens, the brakes do NOT engage, and the car continues at the speed you are
trying to slow down from. So to address this (when it happens), you must lift off the brake,
and then apply again... but just a bit more slowly. It should then engage and you can then apply
much more pressure. There have been several times when this has NOT worked for me,
and I had to retry again... all this while barrelling down at a speed I do not want to be at,
and heading for pylons I do not want to hit. (pucker factor rears a very ugly head here).
This is what we are now having to do.
Threshold braking and or braking sooner involves applying the brakes sooner and only enough so they then engage
so you can then apply as much pressure as needed for this element.
Last edited by NTMD8R; 09-05-2018 at 10:35 PM.
09-05-2018, 10:41 PM
#6
Melting Slicks
Thread Starter
Mike, my after market wheels are knurled.
I THINK the problem is that we are trying to engage the brakes too much right at first, which
MIGHT cause the brakes to lock the wheels for a miniscule instant, which might then tell the ABS that we
are on ice..... maybe ?????
Going to "easier" pads might address this.... (might, maybe, hope, who knows, and all other unknowns)
It has NEVER happened to me in any of my other 9 Corvettes during 38 years of AutoX.
I THINK the problem is that we are trying to engage the brakes too much right at first, which
MIGHT cause the brakes to lock the wheels for a miniscule instant, which might then tell the ABS that we
are on ice..... maybe ?????
Going to "easier" pads might address this.... (might, maybe, hope, who knows, and all other unknowns)
It has NEVER happened to me in any of my other 9 Corvettes during 38 years of AutoX.
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Mikec7z (09-05-2018)
09-05-2018, 10:43 PM
#7
wow, so it is the abs computer then for sure?
Another problem with these damn cars that can kill someone. This is getting frustrating.
I dont think HP tuners gives access to braking programming yet.
If someone could create a solution tune for the ABS computer, that would be great.
Another problem with these damn cars that can kill someone. This is getting frustrating.
I dont think HP tuners gives access to braking programming yet.
If someone could create a solution tune for the ABS computer, that would be great.
Last edited by Mikec7z; 09-05-2018 at 10:49 PM.
09-05-2018, 10:45 PM
#8
Safety Car
Tires spinning is very easy to figure out. Take some white shoe polish from your kit (always carry it while autocrossing to check tire pressures and roll over) and mark the tire and rim in several places. Do a run and look at the marks.
For NTMD8R. So you are merrily driving through a slalom or straight for some time after the last brake application and you hit the brakes and they do not stop you???? That is a major safety problem. You are saying that for no reason the brakes decide not to work. If that happens why aren't we having accidents daily in our street driven C7s?
For NTMD8R. So you are merrily driving through a slalom or straight for some time after the last brake application and you hit the brakes and they do not stop you???? That is a major safety problem. You are saying that for no reason the brakes decide not to work. If that happens why aren't we having accidents daily in our street driven C7s?
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Mikec7z (09-05-2018)
09-05-2018, 10:48 PM
#9
they are slamming their brakes on insanely hard, and the rate of decel on each wheel is probably BEYOND what GM allows for, so they are right, the car probably THINKS it is on ice... when in reality it is just being driven by a very aggressive driver with better brake pads.
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09-05-2018, 10:54 PM
#10
i hope you guys start documenting this with your PDR... does it show on the PDR that the brakes are applied when this is occurring, via the brake meter in red?
If so, i would start documenting case after case of this and posting it up here... a lawyer will jump on this in a heartbeat and force GM to come out with a reflash for the abs computer.
This is BS that cars are still doing this... so late in production run, and they don't have a fix for the earlier year c7z's.
Keep the brakes fully depressed as hard as you can push them, and dictate the time in hours and minutes when it occurs, so that the tech can go back through the car's computer and see where/when it happened, and see that the car's speed did not decrease. I would get in a location where you dont have to actually stop and wont hit something, and i would let the car roll as long as possible in this "mode" that it does, and get it recorded on PDR.
This is a huge lawsuit. They need to fix asap.
If so, i would start documenting case after case of this and posting it up here... a lawyer will jump on this in a heartbeat and force GM to come out with a reflash for the abs computer.
This is BS that cars are still doing this... so late in production run, and they don't have a fix for the earlier year c7z's.
Keep the brakes fully depressed as hard as you can push them, and dictate the time in hours and minutes when it occurs, so that the tech can go back through the car's computer and see where/when it happened, and see that the car's speed did not decrease. I would get in a location where you dont have to actually stop and wont hit something, and i would let the car roll as long as possible in this "mode" that it does, and get it recorded on PDR.
This is a huge lawsuit. They need to fix asap.
Last edited by Mikec7z; 09-05-2018 at 11:10 PM.
09-05-2018, 10:54 PM
#11
Team Owner
they are slamming their brakes on insanely hard, and the rate of decel on each wheel is probably BEYOND what GM allows for, so they are right, the car probably THINKS it is on ice... when in reality it is just being driven by a very aggressive driver with better brake pads.
Please lighten on the mad theroies your killing me!
09-05-2018, 10:57 PM
#12
how is it a theory when 3 people in less than a few hours, all chime in that it has happened to all of them?
Its a real problem. You want your car to not brake when you hit the brakes as hard as you can hit them? Grow up, get out of here.
Its a real problem. You want your car to not brake when you hit the brakes as hard as you can hit them? Grow up, get out of here.
Last edited by Mikec7z; 09-05-2018 at 10:57 PM.
09-05-2018, 11:15 PM
#13
09-06-2018, 02:08 AM
#14
Team Owner
So is the air bubbles in the intercooler, Then it is the 650 limit hp GM has comes in to play! But only at sea level on Tuesdays!
Glad I didn't get a lemon!
09-06-2018, 02:43 AM
#15
Melting Slicks
Member Since: Feb 2009
Location: Dallas Georgia
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2020 Corvette of the Year Finalist (track prepared)
C3 of Year Winner (track prepared) 2019
Please don't **** this thread up with your constant bickering. I have many threads about ICE mode, there has been no solution. The combination of different wheel sizes and aftermarket pads leads many of us to experience ICE mode with the car. Unfortunately, with Tadge's response to the topic, nothing is going to happen to "fix" this issue.
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09-06-2018, 07:31 AM
#16
I have many threads about ICE mode, there has been no solution. The combination of different wheel sizes and aftermarket pads leads many of us to experience ICE mode with the car. Unfortunately, with Tadge's response to the topic, nothing is going to happen to "fix" this issue.
09-06-2018, 11:14 AM
#17
Instructor
It has happened to me only once on track, but it certainly happened. I was running stock sized wheels on Cup2's with a completely stock brake setup. I posted about this fairly quickly after it happened, as I was very confused about its origins. Initially, I blamed it on overheated pads, but after quite a bit of research, it was clearly an "ice mode" issue.
In my circumstance (and most of those that I have seen posted) the ice mode engages upon a very quick transition from accelerator to brake combined with aggressive pressure on the brake. I suspect that some manner of unsettling the car at the same time (bumps, dips, etc.) also play a part in engaging ice mode. My event happened at turn 10 at Hallett. Turn 10 is after a moderate straight (110 mph or so) and braking to a long apex lower-medium speed corner (58 mph or so). I have watched the pdr several times and I did not find anything different (ie later) concerning my braking into the corner. I ended up switching to ST-43 pads, but I have only had one brief track session on those pads when I was running at only 7/10 pace. The initial feel was if I was pushing against a wall with my foot with little braking power. The pdr is unremarkable, but it was a pants crapper at the time for sure.
In my circumstance (and most of those that I have seen posted) the ice mode engages upon a very quick transition from accelerator to brake combined with aggressive pressure on the brake. I suspect that some manner of unsettling the car at the same time (bumps, dips, etc.) also play a part in engaging ice mode. My event happened at turn 10 at Hallett. Turn 10 is after a moderate straight (110 mph or so) and braking to a long apex lower-medium speed corner (58 mph or so). I have watched the pdr several times and I did not find anything different (ie later) concerning my braking into the corner. I ended up switching to ST-43 pads, but I have only had one brief track session on those pads when I was running at only 7/10 pace. The initial feel was if I was pushing against a wall with my foot with little braking power. The pdr is unremarkable, but it was a pants crapper at the time for sure.
09-06-2018, 11:22 AM
#18
Melting Slicks
Thread Starter
For those of you who don't know what it is like, here's a short PDR video of me
going through a wall of cones.....
Notice the brake indicator is showing 2 bars... and my foot and leg are pressing as hard as I can.
going through a wall of cones.....
Notice the brake indicator is showing 2 bars... and my foot and leg are pressing as hard as I can.
Last edited by NTMD8R; 09-06-2018 at 11:24 AM.
09-06-2018, 11:27 AM
#19
Melting Slicks
Thread Starter
OK, another question... is it only with Z06 ???????
A friend of mine has a 2015 Z51 A8, and autocrosses it. He does VERY well,
and one of the national champion guys who drove mine last Monday also drives it.
They have both NEVER experienced Ice Mode in that car.
A friend of mine has a 2015 Z51 A8, and autocrosses it. He does VERY well,
and one of the national champion guys who drove mine last Monday also drives it.
They have both NEVER experienced Ice Mode in that car.
09-06-2018, 11:50 AM
#20
No, this problem can occur with any car with ABS. If you google search for Ice mode ABS you will find many cars with the problem. Here is a link to 300+ comments on https://rennlist.com/forums/997-gt2-...got-me-21.html
on Porsches with the problem.
The problem is much more likely to occur when running aggressive race brake pads and suddenly hitting the brakes. ABS ice modes is not- brake booster vacuum fade, not brake fluid boiling, not brake pad over temp, not tires slipping on the rims. The problem is caused because the deceleration rate of the car exceeds the programmed ABS threshold and ABS goes into "ice mode" as a fail safe. The brake pedal does not pulsate like when ABS is engaging to prevent a locked wheel. In Ice Mode, the brake pedal is hard and the brakes function at less than 50%.
on Porsches with the problem.
The problem is much more likely to occur when running aggressive race brake pads and suddenly hitting the brakes. ABS ice modes is not- brake booster vacuum fade, not brake fluid boiling, not brake pad over temp, not tires slipping on the rims. The problem is caused because the deceleration rate of the car exceeds the programmed ABS threshold and ABS goes into "ice mode" as a fail safe. The brake pedal does not pulsate like when ABS is engaging to prevent a locked wheel. In Ice Mode, the brake pedal is hard and the brakes function at less than 50%.
