Ice mode solution?

cossie1600 · 05-11-2011, 12:52 AM

I was busy and had to leave my XP10s on the past two weeks. In an autox at a smooth lot two weeks ago, the brakes were fine. On a bumpy lot this past Sunday, I experienced ice mode no matter how soft or hard I got on the throttle. I ended up having to brake at least one set of gate earlier and I still had trouble making through the turns as the brakes would grab and then go into ice mode. I understand my race pads had everything to do with it, but god the ABS is awful. Brake temperature might not help the situation, but I can tell you ice mode hit from turn 1 to the last turn. It just wouldn't go away no matter what I tried. The aggressive pads and the less than ideal surface had everything to do with it. I had no problem at a smooth lot just a week ago.

spearfish25 · 05-11-2011, 09:28 AM

Quote:

Originally Posted by Shamu

Id be intersted to see if another 370Z could brake as well as my car in braking zone with my ABS off.

A car with a skilled driver and no ABS will stop faster than a car with ABS. It's well known that ABS increases braking distances. But it's the best solution for people who won't threshold brake correctly.

ChrisSlicks · 05-11-2011, 10:07 AM

Quote:

Originally Posted by spearfish25

A car with a skilled driver and no ABS will stop faster than a car with ABS. It's well known that ABS increases braking distances. But it's the best solution for people who won't threshold brake correctly.

This is true in a straight line. However when you're braking mid corner (not uncommon in auto-x) or don't have your brake bias dialed in then it will be longer and/or increase your chance of lock up.

travisjb · 05-11-2011, 10:39 PM

Quote:

Originally Posted by ChrisSlicks

This is true in a straight line. However when you're braking mid corner (not uncommon in auto-x) or don't have your brake bias dialed in then it will be longer and/or increase your chance of lock up.

also pretty typical in a passing situation... I locked up and had a couple offs trying to pass on a dirty line, was exacerbated by a bad setup and my lack of threshold braking skills but clearly would not have happened with ABS

laze1 · 05-14-2011, 06:53 PM

I fixed my 350Z by removing the Yaw-sensor that controls the VDC...then all my braking issues went away. Mainly the hard pedal and the inside corner brake overheating (VDC was trying to straighten the car out of a slide)...all these occurred during full-on track seasons with OEM Brembos and Carbotech XP10 F & R, Hoosier R6 tires...

Not sure if this can be done on a 370Z, But I would assume so...

http://my350z.com/forum/5506158-post1.html

cossie1600 · 05-14-2011, 09:18 PM

If you are tracking with your VDC, you have more to be concerned about than just ice mode

laze1 · 05-14-2011, 09:39 PM

Note sure what you are implying here...

but even when you push the VDC button to turn it off ... VDC/Brake Control are still functioning but on a diminished level.

Quote:

Originally Posted by cossie1600

If you are tracking with your VDC, you have more to be concerned about than just ice mode

cossie1600 · 05-15-2011, 12:12 AM

VDC no, ABLS and EBD yes. Computer doesn't apply the brakes for you with the VDC off. If you do use it, it would distribute the braking force accordingly.

laze1 · 05-15-2011, 09:50 AM

In a 350Z, even with VGC in the off position, EBD is still working, so if you are in a drifting condition...it will apply one or more brakes in an attempt to straighten out the car...however not sure about the 370Z.

Both my 350Zs had this issue (2004 & 2006), and was completely resolved by removing the Yaw sensor that drives all the VDC related computing.

Note: I have not tracked my 370Z, so I can't verify that condition exists in that model. We need some 370Z TT or W2W racers to speak up here.

cossie1600 · 05-15-2011, 10:29 AM

you need to layoff the fast and furious bible or do some racing 101 classes. braking in the middle of a turn is like eating beans before an anal scene

laze1 · 05-15-2011, 05:06 PM

?????

Note sure this is going anywhere, dropping out of this thread

Quote:

Originally Posted by cossie1600

you need to layoff the fast and furious bible or do some racing 101 classes. braking in the middle of a turn is like eating beans before an anal scene

Brazilbro · 05-15-2011, 10:00 PM

I think Laze1 was implying that the car would brake its self without applying the brakes to try and pull the car out of a drift. I don't know but I can drift my Z from side to side and the computer doesnt try and stop me

cossie1600 · 05-16-2011, 12:43 AM

See #83.

No the car would only brake itself if you leave the VDC on or you light up the inner rear. (it would apply brakes to control that at least)

Philipp · 05-16-2011, 08:55 PM

Quote:

Originally Posted by cossie1600

you need to layoff the fast and furious bible or do some racing 101 classes. braking in the middle of a turn is like eating beans before an anal scene

ChrisSlicks · 07-07-2011, 04:52 PM

I read Mike's blog post and wanted to comment a little bit on the ice-mode as I had it on track for the first time this weekend (normally I just get it at auto-x). I was out in an open track session after the time trials, was running on the RE-11 street tires and had been out for 10 laps or so, the brakes were good and hot but not overheating. The suspension was dialed in fairly soft as the time trial ran under damp conditions and I had forgot to change the shock settings before going out.

Heading into the braking zone to turn 11 at NHMS is a gentle left with light to moderate acceleration followed by a pretty much straight braking zone but can be a little bit bumpy. As soon as I jumped on the brakes the pedal went hard and I only had about 50% braking force. I just rode it out as there was plenty of extra track and run off and I did manage to slow down enough in a straight line to eventually turn into the corner.

As it only happened the one time it is hard to say definitively what the issue is, but based on that experience and that of Travis's I'm thinking it is related to having a low traction situation in the rear and the ABS system's poor modulation. As the weight was transferring forward under braking the rear went light and the ABS system was unable to release enough pressure to the rear to unlock the wheel so instead it appears to release pressure to the entire braking system. It is also possible that I momentarily locked a front wheel by jumping onto the brakes too suddenly before the weight had transferred.

At this point the only factor I think heat plays in this is that the brake pads are performing better under the moderate heat and have a higher coefficient of friction. Similarly an aggressive bite pad can trigger the same condition with a much lower heat especially on a less grippy tire.

The other heat condition that seems to trigger an ice-mode like feeling is pad fade. If you get the pads outside of there operating range then their friction falls away, sometimes dramatically (especially the stock pads) and the rear brake is forced to do more of the braking causing rear lock up and poor braking performance. But with the proper track pads this shouldn't be an issue.

I was using the AP Racing rotor paint and caliper temperature stickers, the paint all turned white indicating rotor temperatures in excess of 1130F and the calipers peaked at just a hair under 500 degrees. There was some significant pedal fade on the slow in lap but not under racing conditions. Was running AP Racing 600 fluid. Rear brakes rotors reached 1050F and calipers were only 360F.

05-14-2011, 06:53 PM	#80 (permalink)
laze1 Base Member Join Date: Sep 2009 Location: Atlanta Posts: 91 Drives: 370Z Nismo #75 K23 Rep Power: 16	I fixed my 350Z by removing the Yaw-sensor that controls the VDC...then all my braking issues went away. Mainly the hard pedal and the inside corner brake overheating (VDC was trying to straighten the car out of a slide)...all these occurred during full-on track seasons with OEM Brembos and Carbotech XP10 F & R, Hoosier R6 tires... Not sure if this can be done on a 370Z, But I would assume so... http://my350z.com/forum/5506158-post1.html Last edited by laze1; 05-14-2011 at 07:10 PM.

05-15-2011, 10:00 PM	#87 (permalink)
Brazilbro A True Z Fanatic Join Date: Mar 2009 Location: Indianapolis, IN Posts: 1,131 Drives: Juke/240Z Rep Power: 848	I think Laze1 was implying that the car would brake its self without applying the brakes to try and pull the car out of a drift. I don't know but I can drift my Z from side to side and the computer doesnt try and stop me __________________ Juke AWD/240Z SR20 08 Evo 10(Stage 2) SOLD Fastest Sport 6spd 370Z 11.8 @126.5SOLD

07-07-2011, 04:52 PM	#90 (permalink)
ChrisSlicks A True Z Fanatic Join Date: Mar 2009 Location: North East Posts: 6,203 Drives: 09 370Z Sport M6 Rep Power: 653	I read Mike's blog post and wanted to comment a little bit on the ice-mode as I had it on track for the first time this weekend (normally I just get it at auto-x). I was out in an open track session after the time trials, was running on the RE-11 street tires and had been out for 10 laps or so, the brakes were good and hot but not overheating. The suspension was dialed in fairly soft as the time trial ran under damp conditions and I had forgot to change the shock settings before going out. Heading into the braking zone to turn 11 at NHMS is a gentle left with light to moderate acceleration followed by a pretty much straight braking zone but can be a little bit bumpy. As soon as I jumped on the brakes the pedal went hard and I only had about 50% braking force. I just rode it out as there was plenty of extra track and run off and I did manage to slow down enough in a straight line to eventually turn into the corner. As it only happened the one time it is hard to say definitively what the issue is, but based on that experience and that of Travis's I'm thinking it is related to having a low traction situation in the rear and the ABS system's poor modulation. As the weight was transferring forward under braking the rear went light and the ABS system was unable to release enough pressure to the rear to unlock the wheel so instead it appears to release pressure to the entire braking system. It is also possible that I momentarily locked a front wheel by jumping onto the brakes too suddenly before the weight had transferred. At this point the only factor I think heat plays in this is that the brake pads are performing better under the moderate heat and have a higher coefficient of friction. Similarly an aggressive bite pad can trigger the same condition with a much lower heat especially on a less grippy tire. The other heat condition that seems to trigger an ice-mode like feeling is pad fade. If you get the pads outside of there operating range then their friction falls away, sometimes dramatically (especially the stock pads) and the rear brake is forced to do more of the braking causing rear lock up and poor braking performance. But with the proper track pads this shouldn't be an issue. I was using the AP Racing rotor paint and caliper temperature stickers, the paint all turned white indicating rotor temperatures in excess of 1130F and the calipers peaked at just a hair under 500 degrees. There was some significant pedal fade on the slow in lap but not under racing conditions. Was running AP Racing 600 fluid. Rear brakes rotors reached 1050F and calipers were only 360F. __________________ Hotchkis ARB \| Stillen CAI \| Art Pipes \| Berk CBE \| Stillen AP Racing Brakes \| AE Performance Oil Cooler \| BC Racing ER Coilovers \| Doran Control Arms

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05-11-2011, 12:52 AM	#76 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	I was busy and had to leave my XP10s on the past two weeks. In an autox at a smooth lot two weeks ago, the brakes were fine. On a bumpy lot this past Sunday, I experienced ice mode no matter how soft or hard I got on the throttle. I ended up having to brake at least one set of gate earlier and I still had trouble making through the turns as the brakes would grab and then go into ice mode. I understand my race pads had everything to do with it, but god the ABS is awful. Brake temperature might not help the situation, but I can tell you ice mode hit from turn 1 to the last turn. It just wouldn't go away no matter what I tried. The aggressive pads and the less than ideal surface had everything to do with it. I had no problem at a smooth lot just a week ago.

05-14-2011, 09:18 PM	#81 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	If you are tracking with your VDC, you have more to be concerned about than just ice mode

05-15-2011, 12:12 AM	#83 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	VDC no, ABLS and EBD yes. Computer doesn't apply the brakes for you with the VDC off. If you do use it, it would distribute the braking force accordingly.

05-15-2011, 09:50 AM	#84 (permalink)
laze1 Base Member Join Date: Sep 2009 Location: Atlanta Posts: 91 Drives: 370Z Nismo #75 K23 Rep Power: 16	In a 350Z, even with VGC in the off position, EBD is still working, so if you are in a drifting condition...it will apply one or more brakes in an attempt to straighten out the car...however not sure about the 370Z. Both my 350Zs had this issue (2004 & 2006), and was completely resolved by removing the Yaw sensor that drives all the VDC related computing. Note: I have not tracked my 370Z, so I can't verify that condition exists in that model. We need some 370Z TT or W2W racers to speak up here.

05-15-2011, 10:29 AM	#85 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	you need to layoff the fast and furious bible or do some racing 101 classes. braking in the middle of a turn is like eating beans before an anal scene

05-16-2011, 12:43 AM	#88 (permalink)
cossie1600 A True Z Fanatic Join Date: Jun 2009 Location: californee way Posts: 5,380 Drives: 370, Leaf Rep Power: 30	See #83. No the car would only brake itself if you leave the VDC on or you light up the inner rear. (it would apply brakes to control that at least)