LagunaSecaZ06

I have 2016 Z06-Z07-MPSC2 and the car worked flawlessly at Laguna Seca, Thunderhill and on the street. I converted to Girodiscs/ST43 and Michelin Pilot SS because I wore out front ceramic rotors after 8 track days(I was going through a set of ceramic pads every track day, the first set of ceramic pads lasted 5 full track days). I was also going through MPSC2 every two track days, so I switched to MPSS(non-runflat) to reduce the tire expense. The Girodisc and Raybestos ST43 were having ice mode issues at Laguna Seca with MPSS. It was very problematic not having confidence slowing for turns or if I was going to make a corner. After talking to to Girodisc, I installed Raybestos ST31 front and back and no issues at Laguna Seca. I do ABS threshold braking(thats what I call it). I brake hard enough to engage the ABS and then back off so the ABS is not pulsing. With the ST43 I was only getting about 50% braking power (at Laguna Seca) and I could not engage the ABS pulsing. With the ST31, it works just as good as the stock carbon ceramic setup.

I used both the ST43 and ST31 on the street. The ST43 was much too noisy in slow driving(although quiet when not coming to a complete stop and quiet at the track). The ST31 is now noiseless after the track day on the street. The dust is pretty bad, so I have give the rims a good washing once week and the dust accumulates on the driveway after cleaning. So then I have to sweep and rinse off the driveway.

Overall, the situation is fixed for me. I would recommend anyone having this problem is to revert back to stock pads. This is the cheapest and easiest solution. I would then run the stock brakes with the track tires and wheels and see if your problem is gone.

If anyone disagrees me, I have set of Raybestos ST43 for sale at $200 for a front and rear set. On

Mikec7z

its a shame manufacturers don't offer 2 tuning options and inform the public which is on their car currently.

If a person slammed on their brakes, the car would stop worse, than if they just put them on normally at times. That is a very big deal.

For racers and people who know their cars well, the manufacturer should offer another option that disables the ice mode.

I live in florida, odds of me ever hitting ice are slim to none... odds of me hitting my brakes as hard as I can in an emergency situation, are highly possible.

I was hoping that it was only an occurrence with offset wheel sizes... but instead it seems it can happen with stock wheels sizes, this is not good.

I have heard someone explain this happened to their car when they rear ended someone, they were driving another kind of car than a vette, so it is an abs standard code... on many models I am sure, but it needs to be addressed because this is very dangerous.

Mikec7z

in the meantime, it would be good if a vendor could come up with aftermarket tuning software for the abs. That is probably the only way to get the manufacturers to offer a product stock... similar to when DSC sport came out with their suspension upgrade, and then chevy followed and charges 300+ dollars for it. Same should be for the abs system, they should have a race calibration.

LagunaSecaZ06

https://rennlist.com/forums/997-gt2-...l#post14202513 read post 308

Quote:
Originally Posted by nwGTS
wait what? you are programming your suspension unit to also raise brake line pressure via dampening?
can you elaborate?
Quote:
Originally Posted by ZMC-ZH
I think what he meant was that he can stiffen the shocks based on pressure on the brake pedal, basically having a setup predicting the g-forces about to come in. Same exists based on accelerator pedal travel.
I have been toying with the idea of getting this DSC box for a while now, already read the manual but still haven't pulled the trigger.
Yes, I am using DSC Sport controller and DSC Sport tuning software to tune the dampers to counter dynamic weight transfer.



Quote:
Originally Posted by Steven_S
How are you changing the damping force relative to increasing brake pressure?
I am using DSC Sport controller, the damping commands to the load is an additive of a minimum damping value, which in my car is set at 10% in Normal Mode/20% in Sport mode with zero load(zero brake pressure or g force). Below are screenshots of two examples of Brake pressure tuning tables that I have been using:

This example shows when brake line pressure is at 30 bar the 55.5% damping is added to the front dampers for compression event and 33.5% damping added to the rear dampers for rebound event. The rear rebound is to assist the front compression to reduce nose dive thus reducing toe deviation as well. The "Decay" is 1000 millisecond of holding this damping command after pressure drops.




This is example at 50 bar.




The brake pressure damping commands works in conjunction with G force damping commands.




Quote:
Originally Posted by Steven_S
Are you decreasing the compression damping to increase the rate of weight transfer to the front?
No, since the electronic suspension system I am using doesn't have a default(or base) damping value that starts high. Instead its starts low and adds. I suppose the software can be written to work the opposite way but I have it tuned well to paired with the mods that I've done this way.

Warp Factor

Mike has put up some really good theories in various threads. If they are beyond your very limited technical comprehension, that is nobody's fault but your own.

NTMD8R

Another thing to ponder...
Last year we had a 2008 Z06, with a few "modifications"... 500 RWHP, koni double-adjustable shocks,
Strano front sway bar, Ferodo DS2500 pads, and ran Hoosier A7 tires.

At NO time did we experience ice mode.

So... is there a change in the programming of the ABS from C6 to C7 ?

Mikec7z

So you are saying Mike from DSC Sport might be a good one to consult on this topic? Ironic, i was using the dsc as a metaphor, but now it may turn out there is a correlation and DSC Mike can help us out.

badhabit_wb

I ran the Girodisc/st-43 combo front and rear and did not experience this. Did you just run on the front? When I changed I decided to do both ends to keep the balance the factory had. The only problem I had, and this was just at VIR, is that sometimes the pedal would go half way to the floor before it started braking. That was the reason I put the bbk on. Since then it hasn't happened. I am running cup 2's in the factory sizes on factory wheels if that makes a difference.

Mikec7z

so, i have the DSC controller on my car, not sure if it helps the problem or not... those of you having the problem, do you have the DSC? does it make a noticeable difference either way to the best of your observations on this ice mode circumstance?

Poor-sha

I had someone send me some PDR data from an ice mode incident a while back (maybe fleming23?). Unfortunately it didn't have the yaw rate or wheel speed sensor channels which would have really helped. However, looking at the same corner on two laps, one in which he hit ice mode, it was really difficult to see from the data what happened. The brake trace looked the same on both but remember that the PDR data only has the brake pedal position sensor not brake pressure (even though it is on the CAN bus and the Aim Solo DL will capture brake pressure). Both laps also had the ABS active channel lit, but that's going to be the case under any heavy braking due to the dynamic brake balance. The only thing that was different was that the longitudinal Gs in the lap with ice mode were about half the other lap. So in other words, the car was slowing but at about half the rate. I might try to find that PDR file and do a video breakdown of it but in the end I couldn't draw any helpful conclusions.

Personally, I've never experienced ice mode in any of the 4 C7s I've owned and tracked but clearly it is a thing. I've also tried at least 5 different types of brake pads and probably 7 or so different tire make/size combinations. However, I don't really like pads that have a lot of bite/initial torque as I find them hard to modulate during turn in. I'm also not the slam on the brakes at the last minute guy and instead I like to ramp up the brake pressure to give the weight time to shift. I started doing that early on with my C6Z since the front got kind of light at high speed and you had to do that or you would be right in to the ABS.

My theory is that this is brought on by a combination of high torque pads and really aggressive initial application. It's likely causing an initial lockup that the car interprets as ice. The other thing I have experienced was that if you had any steering angle and were hard on the brakes you could feel the car bleeding off rear brake pressure to keep the car from rotating but I only had that with my 2015 C7Z.

As far as the DSC controller is concerned, the major differences I noticed under braking was that the car was much more stable under braking since it keeps the front from diving and the rear from unweighting as much. Not only do you not get the dive in the front it actively ramps up the rebound in the rear to help push the rear tires down in to the pavement. As a result, you end up using the rear brakes a lot more and that shows up in better stopping and more rear pad wear. I really don't know if this would help with the folks experiencing ice mode.

LagunaSecaZ06

I would bet that each car and trim (Z07 vs non-Z07 and etc.) package may have different ABS programming. With that said, and I talked to Mike at Girodisc, some cars(years and models) are more susceptible to the problem when modifying. He said that the early Porsches Cayman had ice mode really bad when modified, then it was fixed in a later generation. I think the problem varies based upon the road, tires, brake pads/rotors and suspension. My buddy has a 2009 Z51 Corvette and he runs Raybestos ST43 (stock calipers and rotors and street tires) at that track (my suggestion) and he has no issues. I also believe, as some say, that the driver can exacerbate the issue, by hitting the brakes initially too hard. The driver issue is kind of a blaming the victim situation. If you were to remove the ABS fuse and a driver hit the brakes too hard, a wheel would lock up. The driver would immediately reduce(but not completely remove) brake pressure and still get 100% of the brake capability. In ABS ice mode, you have to COMPLETELY, let off the brake and re-apply which is not advisable going into Turn two at 130MPH or Turn 8 at 110MPH at Laguna Seca or at an auto cross.

LagunaSecaZ06

Your comments are spot on. The Porsche thread I referenced, Tom at TPC racing was using a DSC controller to combat the problem(on a Porsche) and wrote a detailed write up of his settings.
https://rennlist.com/forums/997-gt2-...l#post14202513

Your driver style also contributed to you not having the problem. I would only get Ice mode on two corner entries at Laguna Seca. The other corners where I use the brakes, I didn't have to brake as hard for the upcoming turns and hence didn't have the problem. I only had the problem in Turn 2 (hair pin after the front straight) and Turn 8 (slowing from the corkscrew after going up the back straight). While I could probably train my self to eliminate the problem, I felt that switching pads would also be a safe option.

LagunaSecaZ06

I ran ST43 front and back. Now I run ST31 front and back.

Mikec7z

the problem for me is not so much a turn at a race track where i can practice getting it right...

the problem is when someone in another car pulls out in front of you on the street, and you slam your brakes on as hard as you can out of instinct, and boom, your breaks are at 30% instead of 100, and the only way to get it to 100%, is to let off of them and thus make things even worse.

it is a safety issue, it can kill literally someone

I believe porsche retuned their abs computers... in later models...

i would like to know if there is anyone out there who CAN tune the abs computers in these cars, aftermarket.

(the problem is, no one will touch this with a 10 ft pole, because then there is a safety liability issue since they tuned the car, if the car later wrecks and hurts/kills someone)

A lady who rear ended someone here in florida, told me this happened to her in her suv, and i honestly thought she was batsh*t crazy and full of it.

Hindsight, she described this to a tee. So it is a real problem and it is causing wrecks. If someone can figure out how to alter the parameters for this abs tune to disable ice mode, let me know.

Mikec7z

has anyone gotten this to happen on a car that has, or started out with, the carbon ceramic brakes?

My guess is, if there are 2 abs tunes in these cars, the ccb cars abs computer is more lenient, since those brakes have more initial bite.

It would be interesting to see if taking the abs programming from the z07 package cars, and putting that code into the NON z07 cars... would keep the regular steel brake cars from having the issue, even after more aggressive pads are added.

IF someone can make that programming transfer from one car to the other?

or is there a single module that can be swapped, and is a different part number for the z07 vs non z07 cars?

... i have no idea

Another way to prove this would be the people who have upgraded to the stock ccb, who started with steel, i suspect they are able to put their cars into ice mode pretty easily if there are indeed 2 different tunes for the vehicles.

NTMD8R

And here are 2 more short clips of 2 of those other drivers in my car, experiencing Ice Mode....

pkincy

Thank you folks I think I now understand what it is and clearly this is a huge safety issue. My whole experience and understanding with ABS over the past 25 years was that it is designed so that in a panic stop situation, the driver could mash the brakes in an absolute panic and the car would not lock up the brakes but would stop as quickly as possible without lockup. What you are describing is just the opposite. Mr/Mrs Clueless is driving down the street and a child runs out between parked cars chasing a ball and Mr/Mrs Clueless pounds on the brakes in a panicked reaction........and the car doesn't stop. In fact the car only gives 20-30% of its stopping power so that the child is truly smashed and completely run over. So basically in certain situations the ABS not only doesn't stop the car but makes the car impossible to stop. Never ran into this in my C4 Z07 or C5Z, both of which I did autox extensively nor in my mostly street driven C6Z. Frankly seeing those PDR videos it is totally frightening and I wonder if we should even be driving our cars until it is fixed. Under normal driving conditions a competent driver can threshold brake with little problem. It is the panicked situation where the initial reaction is to pound on the brake pedal. So it seems clear that the C7 and apparently Porsche's ABS is sometimes completely ineffective at stopping the car in that situation.

Poor-sha

The difference is that Mr and Mrs clueless aren't running aggressive track oriented pads. These systems are very complex and are tuned to certain expectations for pad and tire mu.

This is also why real pro race cars have dedicated ABS systems that typically require hiring an engineer to setup and tune.

pkincy

So in that case, running stock pads and stock tires we would never experience "Ice Mode?"

Poor-sha

That's what I expect. Have you experiencds ice mode with stock pads?