well, ABS Ice Mode finally got me...
04-08-2011, 12:57 PM
#91
If this is easily repeatable it may be easier to convince Bosch to pay someone a visit. We should try to determine who can most consistently repeat the problem and put them in touch with Bosch. I'll try to find an appropriate contact.
Also, when you say transition speed, let's try to determine precisely what that means. Is it:
1. The rate at which the throttle is closed?
2. The speed that your foot moves from WOT to the brake or the time from foot on throttle to foot on brake?
3. Or, the rate or force with which you apply the brakes?
If 1 or 2 then I'm stumped. If you all think that this is #3 then we can talk about that.
-Noah
Also, when you say transition speed, let's try to determine precisely what that means. Is it:
1. The rate at which the throttle is closed?
2. The speed that your foot moves from WOT to the brake or the time from foot on throttle to foot on brake?
3. Or, the rate or force with which you apply the brakes?
If 1 or 2 then I'm stumped. If you all think that this is #3 then we can talk about that.
-Noah
I can only hope this doesn't happen with smooth controlled braking or during normal high speed driving when you aren't reaching for the absolute maximum brake effort/potential.
04-08-2011, 02:04 PM
#92
Rennlist Member
04-08-2011, 02:09 PM
#93
That would be great!
^This best describes it. Looking to scrub speed with initial brake pressure and immediately back off to maximize traction and not engage ABS.
I'd like to think that the initial brake is not a violent jab but a QUICK and hard squeeze . In the instance of ICE MODE I sense limited brake pressure almost immediately; as if the error has occured before I have a chance to squeeze hard. I found that I can apply a hard squeeze, without a problem, if I come off the gas a "fraction" of a second slower. That's why it leads me to believe there's something to the transition from WOT but I maybe totally off base.
Sorry there's not a lot of science here....just feel which can be misleading.
I'd like to think that the initial brake is not a violent jab but a QUICK and hard squeeze . In the instance of ICE MODE I sense limited brake pressure almost immediately; as if the error has occured before I have a chance to squeeze hard. I found that I can apply a hard squeeze, without a problem, if I come off the gas a "fraction" of a second slower. That's why it leads me to believe there's something to the transition from WOT but I maybe totally off base.
Sorry there's not a lot of science here....just feel which can be misleading.
04-08-2011, 02:12 PM
#94
Nordschleife Master
I've also experienced "ice mode"on several occasions
. It's happened in both in a Gen 2 Cayman S and 997 GT2. The mode is "seemingly" triggered when I transistion very quickly from full throttle to hard brake. Agreed, my transistion isn't happening in 5ms but the faster I transition the more likely the symptom occurs. I've tried to find other commonalities such as uneven road surface but the only constant has been transistion speed. ...
. It's happened in both in a Gen 2 Cayman S and 997 GT2. The mode is "seemingly" triggered when I transistion very quickly from full throttle to hard brake. Agreed, my transistion isn't happening in 5ms but the faster I transition the more likely the symptom occurs. I've tried to find other commonalities such as uneven road surface but the only constant has been transistion speed. ...
04-08-2011, 03:34 PM
#95
Funny how much faster your feet move when you're really deep into a brake zone and still under full throttle
Could be....some type of error in the pre loading causing a freeze/limitation in the allowable brake pressure.
04-08-2011, 04:34 PM
#96
Rennlist Member
^This best describes it. Looking to scrub speed with initial brake pressure and immediately back off to maximize traction and not engage ABS.
I'd like to think that the initial brake is not a violent jab but a QUICK and hard squeeze . In the instance of ICE MODE I sense limited brake pressure almost immediately; as if the error has occured before I have a chance to squeeze hard. I found that I can apply a hard squeeze, without a problem, if I come off the gas a "fraction" of a second slower. That's why it leads me to believe there's something to the transition from WOT but I maybe totally off base.
I'd like to think that the initial brake is not a violent jab but a QUICK and hard squeeze . In the instance of ICE MODE I sense limited brake pressure almost immediately; as if the error has occured before I have a chance to squeeze hard. I found that I can apply a hard squeeze, without a problem, if I come off the gas a "fraction" of a second slower. That's why it leads me to believe there's something to the transition from WOT but I maybe totally off base.
04-08-2011, 05:39 PM
#97
I wish some folks would index their tires to wheels so we can see if tire slip has anything to do with this problem.
I have marked mine and they always spin on the rim. Hard to stop well when the wheels lock up and the tires keep on spinning.
dr
I have marked mine and they always spin on the rim. Hard to stop well when the wheels lock up and the tires keep on spinning.
dr
04-12-2011, 12:44 AM
#99
Burning Brakes
I'm guessing it's all of the above or full throttle followed by fast as possible hard/jab style braking resulting from the drivers effort to condense a short brake zone or brake deeper in a longer brake zone which could mean it can be duplicated in any car w/ the same brake system and it's the driver that's making the real difference.
I can only hope this doesn't happen with smooth controlled braking or during normal high speed driving when you aren't reaching for the absolute maximum brake effort/potential.
I can only hope this doesn't happen with smooth controlled braking or during normal high speed driving when you aren't reaching for the absolute maximum brake effort/potential.
04-12-2011, 11:26 AM
#102
Huh? Are you not feeling well today? Must be on some meds....
04-12-2011, 11:56 AM
#104
Burning Brakes
04-12-2011, 12:14 PM
#105
From what I can figure from this thread and others is that this is a standard issue w/ ABS systems in all makes of cars.
I you move VERY FAST from full gas to FULL BRAKE abrupt braking (not smooth) you will engage some sort of glitch that causes a hard high pedal with very little pressure if any. Tire make or size doesn't matter. This is especially troubling for lotus owners because the car is very light weight and doesn't make tons of power so similar to braking in say a spec miata you are challenged with braking incredibly late with a super fast move from full gas to full brake.
This has nothing to do with tires moving on the rims which is from starting with a very low tires pressure (i start as 22 psi) and probably happens only on the first couple of laps before the tire pressures come up over 30 psi.
I you move VERY FAST from full gas to FULL BRAKE abrupt braking (not smooth) you will engage some sort of glitch that causes a hard high pedal with very little pressure if any. Tire make or size doesn't matter. This is especially troubling for lotus owners because the car is very light weight and doesn't make tons of power so similar to braking in say a spec miata you are challenged with braking incredibly late with a super fast move from full gas to full brake.
This has nothing to do with tires moving on the rims which is from starting with a very low tires pressure (i start as 22 psi) and probably happens only on the first couple of laps before the tire pressures come up over 30 psi.