[GunMetalGrey]

Brake pad comparison

[RamAir02]

~35 track days on the car. Never had Ice Mode issues

[GunMetalGrey]

Originally Posted by RamAir02

~35 track days on the car. Never had Ice Mode issues

Stock pads?

[GunMetalGrey]

Originally Posted by GunMetalGrey

Brake pad comparison

Actually given how crazy expensive these Conalt XR3’s and that this is a test, I’ll probably go with G-Loc R8

[cdb95z28]

For those who have voted yes, it would be helpful to state what your pad and tire choice was when ice mode occurred. Even venue can play a part (surface). I think we will find a trend among that info.

Gun Metal, I recall at some point you had installed a different set of wheel bearings. Where they OE GM bearing or aftermarket? Had you had any ice mode before the install of the new bearings? The bearings have the ABS reluctor wheel within them. It could be a variable. Possibly a delinquency in the aftermarket version?

[RamAir02]

Originally Posted by GunMetalGrey

Stock pads?

OE pads for most of those track days. Recently switched to DS1.11 and have a handful of track days on those pads

[GunMetalGrey]

Originally Posted by GunMetalGrey

Brake pad comparison

Originally Posted by cdb95z28

For those who have voted yes, it would be helpful to state what your pad and tire choice was when ice mode occurred. Even venue can play a part (surface). I think we will find a trend among that info.

Gun Metal, I recall at some point you had installed a different set of wheel bearings. Where they OE GM bearing or aftermarket? Had you had any ice mode before the install of the new bearings? The bearings have the ABS reluctor wheel within them. It could be a variable. Possibly a delinquency in the aftermarket version?

Yes good idea thanks! That would be very helpful.

Also, on behalf of Ken Hill Coaching, he accidentally chose yes when he meant to chose no, in other words, he has not had any ice mode hard pedal in his ZLE and his pads are Ferado DS, 1.11.

This means no one with a ZLE has actually voted yes for ice mode Hard brake pedal yet since SCCAForums does not have a ZLE

I think I count as a ZLE considering I have the ABS module from a ZLE but my car is a tracked prepped ZL1 with lots of suspension and brake upgrades… I did get a ice mode hard pedal very briefly but I am also using hawk DCT 60s and I was by no means trying to brake smoothly (I was testing the new ABS module)

Wow, good memory on the wheel bearings, I’m impressed, that was a axtually a waste of money and missdiagnosis, it was actually the long tube headers in contact with the engine haha

[Scargoes]

Originally Posted by GunMetalGrey

This means no one with a ZLE has actually voted yes for ice mode Hard brake pedal yet since SCCAForums does not have a ZLE

Before making that assumption, maybe find out if he was referring to his previous car, which was a highly modified ZLE.

[SCCAForums]

Originally Posted by GunMetalGrey

Also, once again, please do not respond to the poll unless you have a ZLE… User SCCAForums, I believe you drive an SS1LE not a a ZLE unless I’m mistaken…

I created this thread to help determine if I’m going to buy a ZLE and switch over all of my engine, brake and suspension parts from my ZL1, this will be time-consuming and expensive, and will determine if there’s any future for me in tracking, so I really need to know that the data I’m getting is accurate

Correct, I had a ZLE though, 2018 and a 2020 ZL1, non 1LE. In my experience, the ZLE exhibits this issue the least of any Camaro option.

And to your other question, a good point… I did run race pads… so may even be less prevalent in a ZLE on OE pads.

Best regards,
Dave

[GunMetalGrey]

Originally Posted by Scargoes

Before making that assumption, maybe find out if he was referring to his previous car, which was a highly modified ZLE.

My bad, Thanks for informing me, appreciated!

[GunMetalGrey]

Originally Posted by SCCAForums

Correct, I had a ZLE though, 2018 and a 2020 ZL1, non 1LE. In my experience, the ZLE exhibits this issue the least of any Camaro option.

And to your other question, a good point… I did run race pads… so may even be less prevalent in a ZLE on OE pads.

Best regards,
Dave

Sorry about that! And Thanks for letting me know this!

What exact Tire Type and track brake pad type did you have on your ZLE? (I’m hoping you had Hawk 60’s or 70’s like me because that would be a common factor and hence fixable)

And while I know this is subjective, how bad was the ice mode hard pedal? Can you describe your experience please? Severity? Frequency etc… Thanks

And when you say the ZLE exhibit this less than other models, I assume that means both severity and frequency?

[NorthGeorgia]

No ice mode - 7K ZLE track miles - primarily Road Atlanta - stock pads/rotors/SRF + 3R tires. Only braking condition to note is lack of heat during first couple laps which can be soft pedal into hardest braking zones. Once tires and brakes have sufficient heat, stock brakes are good for 3-4 time attack flyers but will gradually soften at hardest braking zone (156 to 54). A reduced pace lap and they come back. I also try to focus on smooth threshold brake application and release (vs stomping on them). As comparison, the C6 Z51 would get occasional ice mode at T2 which is immediately after a high-G RH then off camber LH into a quick/short brake zone but I was an overdriving newbie and the car was not always settled.

[BMLMZ]

Ok so why are we using ice mode on the track and not a specifically designed PTM track mode?? Am I missing something??

[NorthGeorgia]

Originally Posted by BMLMZ

Ok so why are we using ice mode on the track and not a specifically designed PTM track mode?? Am I missing something??

Ice Mode is a braking condition (usually on track) where the ABS (and or stability system) thinks the car is sliding on ice and triggers an ABS calibration which results in a stiff (brick) pedal usually causing you to overshoot the corner.

From ASK Tadge copied from Corvette forum ---


"The key to understanding this phenomenon is that a true ‘ice mode’ where specific calibrations are changed due to distinct surface detection doesn’t exist in any way in the ABS control algorithm. We understand the behavior you are describing but it is not a mode detection that can be turned on or off. The calibrations that can cause this long recovery of deceleration are part of the fundamental ABS wheel control calibration. These calibrations are remarkably complex and significantly beneficial in many situations both on and off track and can’t just be shut off in PTM, they are part of the core wheel control function within ABS. If we did not have variable rates of decel recovery the common race track situations you describe such as curb strikes and spike brake applies while cornering would be very poorly controlled.

To achieve the level of performance expected of Corvette the calibrations are quite sensitive. Further, the control is being done based entirely on four wheel speed sensors which are measuring wheels in extremely dynamic situations. Very rarely is any one wheel traveling at the true speed of the car when ABS is needed. Certain very aggressive driving behaviors can cause any number of calibrations that are critical to overall track performance to produce a lag in decel development, eliminating these situations as much as possible is one of the main tasks that require our extensive engineering effort throughout years of vehicle development work.

Given the significant effort put into optimizing these calibrations we have found that in almost all of the cases where this behavior is noticeable to the driver there have been modifications made to the vehicle that effect the ABS calibration. Different tires, brake pads, and suspension components are examples of modifications which can influence this behavior. We try to predict some common changes that an owner might make to a vehicle but we have no way to test every tire on the market or every brake pad and hardware combination. Further, the more we accommodate race tires or brakes the less robust we are to all season tires or lower dust street pads and vice-versa. You would not expect your engine controller to accommodate a new cam shaft or headers without calibration changes so the same logic applies here.

However, if you have changed any of these components you may find that modifying your brake pedal apply to a softer engagement (even very slight changes) can help the system work with your new components. We have many drivers on the team who have never once experienced this situation and turn in exactly the same lap times as those of us who do occasionally find it.

It’s also important to note that this characteristic of ABS control is not unique to Corvette. It can be found in the ABS systems of many suppliers and across most performance oriented cars, particularly those that have had any kind of modifications made to their brakes or suspension systems.

Having watched these discussions for as long as we have been doing chassis controls, we anticipate many great theories on new, easier ways to do this better… but please keep in mind that any new control idea must be able to work in real time. I.e. with no benefit of analysis after the event or knowledge of the next event (event meaning a 20 millisecond departure of a wheel towards lock or similar situation). It also must work with only 4 wheel speeds and none of those speeds will be a perfectly accurate measure of real vehicle speed. It’s a tough task since there are a near infinite number of variables affecting performance and if we optimize around a rare circumstance we will very likely compromise a commonplace event."