ICE mode on track

[bigjae46]

Anytime ABS engages its a grip issue.

Front rebound was the first thing I tried, no effect.

Added wing, no effect.

I'm not a pro driver but this is most certainly ice mode. I am not trailbraking. To mitigate the issue I am straight line braking very early and gently compared to where the other M3s do at the same turn. I am easily 10-20 mph slower into that corner since I cant reliably get the car stopped.

Have you checked the MK60 module for fault codes? The MK60 can have fault codes that may not cause a check engine light or ABS light. Maybe try unplugging the yaw sensor and see if that helps.

I deleted the DSC and the yaw sensor - all I have is the SZL and wheel speed sensors. I only keep the SZL for data purposes. I've only experienced a very rare ice mode issue with the MK60. Although I rarely go heavy on the brakes, pads last over 10 weekends on my car.

[Estoril]

The exit:

[Estoril]

The turn in question.

[eacmen]

If its downhill and bumpy then it is probably too much weight transfer. If adding some trailbraking then it is very likely a grip issue, not ice mode. Or turn down the front rebound if you have an adjustable suspension. May want to brake less for longer and make sure the steering wheel is straight. This might better optimize the overall grip.

Anytime ABS engages its a grip issue.

Front rebound was the first thing I tried, no effect.

Added wing, no effect.

I'm not a pro driver but this is most certainly ice mode. I am not trailbraking. To mitigate the issue I am straight line braking very early and gently compared to where the other M3s do at the same turn. I am easily 10-20 mph slower into that corner since I cant reliably get the car stopped.

[bigjae46]

T5 is bumpy with a fair amoubt of patches but so is T1. I think the pitch of the car and the rears being light is what is causing this issue.

If its downhill and bumpy then it is probably too much weight transfer. If adding some trailbraking then it is very likely a grip issue, not ice mode. Or turn down the front rebound if you have an adjustable suspension. May want to brake less for longer and make sure the steering wheel is straight. This might better optimize the overall grip.

[eacmen]

Is the track smooth or bumpy? Bumpy braking zones will cause a feeling like ice-mode.

T5 is bumpy with a fair amoubt of patches but so is T1. I think the pitch of the car and the rears being light is what is causing this issue.

[bigjae46]

Is the track smooth or bumpy? Bumpy braking zones will cause a feeling like ice-mode.

[Estoril]

At this point because of the braking issue in 5 my line through 4 is quite conservative. I never touch that kerbing. I only have a very slight throttle (10% ish) input.

The only apprach to 5 I havent tried is track right as 4 tends to push you towards the left. I'm usually a cars width from track left. But have played with placing the car various places in the left 2/3 of the track with the same effect.

You might consider that the slight throttle doesn't balance the car as well as throttle commitment before braking. Once I know that my line approaching T4 apex is good, I am as full throttle as the short distance allows/advises. Granted I am running a different brake, tire and suspension setup, but that shouldn't really be the difference between no problem and your problem.

[eacmen]

I'll mention that T5 is not level right-to-left. There is a patch 60% of the surface in the braking zone starting left. Also, if you use any curb in T4, the right side suspension may not have time to fully recover before braking. Which line are you taking through there?

Shenandoah is fine. Some folks are more prone to motion sickness than others. For some, good vision habits can correct those issues. In the right seat its more pronounced than the left. Right seat in some cars like the GT4 can make it a bit more thrilling.

At this point because of the braking issue in 5 my line through 4 is quite conservative. I never touch that kerbing. I only have a very slight throttle (10% ish) input.

The only apprach to 5 I havent tried is track right as 4 tends to push you towards the left. I'm usually a cars width from track left. But have played with placing the car various places in the left 2/3 of the track with the same effect.

[Estoril]

I love the NJ CCA folks but Shen makes me vomit. Not sure how it would help this issue as its uniquely a T5 main issue.

I'll mention that T5 is not level right-to-left. There is a patch 60% of the surface in the braking zone starting left. Also, if you use any curb in T4, the right side suspension may not have time to fully recover before braking. Which line are you taking through there?

Shenandoah is fine. Some folks are more prone to motion sickness than others. For some, good vision habits can correct those issues. In the right seat its more pronounced than the left. Right seat in some cars like the GT4 can make it a bit more thrilling.

[eacmen]

Give some thought to NJ BMWCCA on Shenandoah, mid-October. Its a very good event with a great group.

https://www.motorsportreg.com/events...-jersey-360258

I love the NJ CCA folks but Shen makes me vomit. Not sure how it would help this issue as its uniquely a T5 main issue.

[Estoril]

No, last event this season is VIR with audi in november.

Give some thought to NJ BMWCCA on Shenandoah, mid-October. Its a very good event with a great group.

https://www.motorsportreg.com/events/shenandoah-driver-school-summit-point-circuit-bmw-cca-new-jersey-360258

[eacmen]

Are you out on Main this weekend with NCC?

No, last event this season is VIR with audi in november.

[Estoril]

Are you out on Main this weekend with NCC?

[eacmen]

Fast forward over a year later and this issue still plagues me every time I am on a push lap going into T5. Similar trace as above nothing really pops out to me as a root cause other than the rears starting to lock up which is expected when braking hard downhill.