[beachBmmr]

I track my g82 a lot. Over 630 miles since August. Ive seen some interesting things happen on track, and Im trying to dig into them.

One such thing has been power reduction on track with no warnings or messages. This happened to me a few weeks ago. When I read the codes something came up about brake disc temperature.

A bit more research leads me to the e90 forums where power reductions are reported and accelerated rear brake wear are reported on e90s.

Many who track are complaining about rear brake wear as well, and the culprit for both might be the electronic differential which is not disabled with dsc off

https://www.e90post.com/forums/showthread.php?t=1117725

Ill be digging in here trying to see if there's similar behavior in the g80 and if there are coding options to eliminate it.

[Ximian]

Do you have a code reader? I'd check the code any time you get a warning or error message to see what's throwing it.

I had a warning about cooling off the brakes and driving moderately even after the car was sitting overnight. That message was caused by a brake piston issue for me so I wouldn't assume the warning message is actually correctly reflecting what the root cause would be.

In my opinion, the rear brakes pads are wearing too fast due to heat. Front brakes have ducts for cooling, the rears don't seem to. I've done track type driving on hilly roads with nice corners where I didn't need to use the brakes much and there was barely any wear. Because of that, I'm not convinced it's some hidden DSC mode you can't disable. I'm also not going out of my to prove that by hooking up the Aim Solo DL 2 to the ECU either so someone else can do that. ( https://aim-sportline.com/download/e...cu_100_eng.pdf )

Only time I've had a power reduction on the G80 was due to low fuel. Depending on when it occurs on track, the power reduction could be caused by fuel starvation to slow you down. I recall with F80s, they'd just stall but I don't have much experience with that generation. It would make sense that this protection was added in G80s to avoid stall and to avoid a pretty serious situation on track.

On my E92 M3, I've never had fuels starvation issues, brake heat temperature warnings (with endurance or spring pads on stock caliper/rotors), or power reductions (limp mode enabled at the top end of the oil temperature gauge).

[beachBmmr]

Originally Posted by Ximian

Do you have a code reader? I'd check the code any time you get a warning or error message to see what's throwing it.

I had a warning about cooling off the brakes and driving moderately even after the car was sitting overnight. That message was caused by a brake piston issue for me so I wouldn't assume the warning message is actually correctly reflecting what the root cause would be.

In my opinion, the rear brakes pads are wearing too fast due to heat. Front brakes have ducts for cooling, the rears don't seem to. I've done track type driving on hilly roads with nice corners where I didn't need to use the brakes much and there was barely any wear. Because of that, I'm not convinced it's some hidden DSC mode you can't disable. I'm also not going out of my to prove that by hooking up the Aim Solo DL 2 to the ECU either so someone else can do that. ( https://aim-sportline.com/download/e...cu_100_eng.pdf )

Only time I've had a power reduction on the G80 was due to low fuel. Depending on when it occurs on track, the power reduction could be caused by fuel starvation to slow you down. I recall with F80s, they'd just stall but I don't have much experience with that generation. It would make sense that this protection was added in G80s to avoid stall and to avoid a pretty serious situation on track.

On my E92 M3, I've never had fuels starvation issues, brake heat temperature warnings (with endurance or spring pads on stock caliper/rotors), or power reductions (limp mode enabled at the top end of the oil temperature gauge).

I have a code reader. It read a temp warning. Tech said it would cause power reduction mode (no rev over 3500). Ive had the low fuel mode too, but that gives a message, this did not

[mzcp]

Originally Posted by beachBmmr

I have a code reader. It read a temp warning. Tech said it would cause power reduction mode (no rev over 3500). Ive had the low fuel mode too, but that gives a message, this did not

Off topic can Bimmerlink close /open valve?

[beachBmmr]

Originally Posted by mzcp

Off topic can Bimmerlink close /open valve?

I was not able to get it to actuate the valve when I tried yesterday.

[og_e46]

At what point(s) on track do you notice the power reduction? Accelerating out of a turn, accelerating in a straight, or somewhere else? I assume you have all traction control disabled?

[beachBmmr]

Originally Posted by og_e46

At what point(s) on track do you notice the power reduction? Accelerating out of a turn, accelerating in a straight, or somewhere else? I assume you have all traction control disabled?

I notice it on acceleration, but I cannot tell when it triggers because theres no message thrown.

Its not pulling power, just sets a rev limit at 3500.

It's happened twice to me on track over about 30 sessions

Yea DSC off

[Polo08816]

Originally Posted by Ximian

Do you have a code reader? I'd check the code any time you get a warning or error message to see what's throwing it.

I had a warning about cooling off the brakes and driving moderately even after the car was sitting overnight. That message was caused by a brake piston issue for me so I wouldn't assume the warning message is actually correctly reflecting what the root cause would be.

In my opinion, the rear brakes pads are wearing too fast due to heat. Front brakes have ducts for cooling, the rears don't seem to. I've done track type driving on hilly roads with nice corners where I didn't need to use the brakes much and there was barely any wear. Because of that, I'm not convinced it's some hidden DSC mode you can't disable. I'm also not going out of my to prove that by hooking up the Aim Solo DL 2 to the ECU either so someone else can do that. ( https://aim-sportline.com/download/e...cu_100_eng.pdf )

Only time I've had a power reduction on the G80 was due to low fuel. Depending on when it occurs on track, the power reduction could be caused by fuel starvation to slow you down. I recall with F80s, they'd just stall but I don't have much experience with that generation. It would make sense that this protection was added in G80s to avoid stall and to avoid a pretty serious situation on track.

On my E92 M3, I've never had fuels starvation issues, brake heat temperature warnings (with endurance or spring pads on stock caliper/rotors), or power reductions (limp mode enabled at the top end of the oil temperature gauge).

Fortunately, in BMW's infinite wisdom, they decided to go with a single piston floating point rear caliper on the G80 instead of keeping or upgrading the F80's two piston monobloc Brembo caliper...

[beachBmmr]

So another data point here I just saw when changing my tires.

Left and right rear are not wearing evenly, I have more wear in the right side. Now maybe this is from brake force being modulated side to side from cornering under braking, given at my track 2/3s of high speed corner entries are lefts….

[D_SheerDrivingPleasure]

Originally Posted by beachBmmr

I track my g82 a lot. Over 630 miles since August. Ive seen some interesting things happen on track, and Im trying to dig into them.

One such thing has been power reduction on track with no warnings or messages. This happened to me a few weeks ago. When I read the codes something came up about brake disc temperature.

A bit more research leads me to the e90 forums where power reductions are reported and accelerated rear brake wear are reported on e90s.

Many who track are complaining about rear brake wear as well, and the culprit for both might be the electronic differential which is not disabled with dsc off

https://www.e90post.com/forums/showthread.php?t=1117725

Ill be digging in here trying to see if there's similar behavior in the g80 and if there are coding options to eliminate it.

Did the 3500 rpm limiter activate with or without your Race Chip installed?

[beachBmmr]

Originally Posted by D_SheerDrivingPleasure

Did the 3500 rpm limiter activate with or without your Race Chip installed?

Without.

[spicoli024]

I had the same issue a couple times. One time was due to low fuel, which triggered limp mode and limited RPMs to 4,000 (received on-screen message and that was understandable). However, another time I was coming out of a carousel and my windows rolled up, seat belt tightened and RPMs were again limited to 4,000 with no on-screen message. I am not sure if something popped up on the dash and I missed it, but this was all well after break-in mileage and service. Probably my 8th lap or so on a 2.3 mile circuit. About a lap thereafter I began to notice some brake fade, but nothing too alarming--the car's reaction was definitely more cause for concern.

[forza1976]

I think I had some pretty serious wear on my X3M on the race track due to driving with DSC on. Traction control was actuating the rear brakes more and caused additional wear. Was my first time on the track with an SUV so I left the nannies on.

Maybe something there?

[jmg]

Originally Posted by beachBmmr

Many who track are complaining about rear brake wear as well, and the culprit for both might be the electronic differential which is not disabled with dsc off

https://www.e90post.com/forums/showthread.php?t=1117725

Ill be digging in here trying to see if there's similar behavior in the g80 and if there are coding options to eliminate it.

Any updates on this? The rear brakes really piss me off, and I don't even have the car yet. On the F80, DSC fully off (hold down the button, not just press it) eliminates any brake use by the stability control.

[beachBmmr]

Originally Posted by jmg

Any updates on this? The rear brakes really piss me off, and I don't even have the car yet. On the F80, DSC fully off (hold down the button, not just press it) eliminates any brake use by the stability control.

No, and I was thinking heat was the culprit, however the design of the hub makes it impossible to get air into the rotor. My last few track days have shown heavier front wear, so I think were going to have to solve this issue with pad compound. There are few options out for rears.

Pagid rsl 29 is coming for them but not yet.

[Boomer 2019]

Originally Posted by beachBmmr

No, and I was thinking heat was the culprit, however the design of the hub makes it impossible to get air into the rotor. My last few track days have shown heavier front wear, so I think were going to have to solve this issue with pad compound. There are few options out for rears.

Pagid rsl 29 is coming for them but not yet.

I don't know if you got my last PM, and this may be a bit premature as I was planning to wait until after my next 2 track days at the end of January, but since you bring it up I will give a preliminary report on my first experience with my custom race pads at Sebring last Friday.

Background: I like everyone else has been suffering on track (in my case since May) with these damned TRW rear calipers. Since then I have driven 9 track days which finally used up the original OEM front pads. Yay front brakes! However during this time I have literally melted 9 sets of OEM rear pads. One for every day on track with no hope of extending them for a second day.

It is only recently that a few pad manufacturers have begun releasing their versions of pads for the G80/82, and from personal experience, and conversions with other track drivers it is apparent that with the possible exception of the Pagid RSL29 (brand new and no actual experience with our cars listed) none of the current offerings is the answer to the problem.

The route I have chosen to take is to send my worn OEM pads along with all the info I could compile about the car, the OEM pads, and the interaction between the two, along with a description of what I want out of pads for my car. Performance on the track; daily driving street manners; and LONGEVITY to a company that will make custom pads. I chose a company which I do not want to name at this time as I have only the 1 track day so far. If what I experienced (a friggin' dream) holds up for a couple of more I will name them. They are a US company (quick turnaround and no overseas shipping delay problems) who make only race pads, and they have been doing it for over 20 years for professional race teams and individuals alike. They have been great to work with and very supportive. They decided on 2 different compounds for the front and rear, and will make adjustments in the future as may be needed or desired by me. I am posting this now to let people know that a solution is probably possible, and who knows, maybe even before the "H" series is released.

The pads: Carbon Ceramic / Backing plates are 4.5mm thick with no attachment points for pad wear sensors / Front compound 15mm thick / Rear compound 12mm thick (this will be increased to 14mm when reordered)

My experience: 5 sessions / 126 total miles / 100 total minutes

Front pad material used: 0mm - no measurable wear
Front pad material remaining: 15mm
Rear pad material used: 0.5mm
Rear pad material remaining: 11.5mm

NVH Street: A soft swooshing or rubbing sound when braking at low speeds - easily tolerated. Squealed only twice briefly and lowly when backing up.
NVH Track: Not noticeable, and who cares anyway.

Rotor wear will take time to be determined, but given the low level of NVH I have hope. The company claims that their compounds are the most rotor friendly in the industry.

[beachBmmr]

Originally Posted by Boomer 2019

I don't know if you got my last PM, and this may be a bit premature as I was planning to wait until after my next 2 track days at the end of January, but since you bring it up I will give a preliminary report on my first experience with my custom race pads at Sebring last Friday.

Background: I like everyone else has been suffering on track (in my case since May) with these damned TRW rear calipers. Since then I have driven 9 track days which finally used up the original OEM front pads. Yea front brakes! However during this time I have literally melted 9 sets of OEM rear pads. One for every day on track with no hope of extending them for a second day.

It is only recently that a few pad manufacturers have begun releasing their versions of pads for the G80/82, and from personal experience, and conversions with other track drivers it is apparent that with the possible exception of the Pagid RSL29 (brand new and no actual experience with our cars listed) none of the current offerings is the answer to the problem.

The route I have chosen to take is to send my worn OEM pads along with all the info I could compile about the car, the OEM pads, and the interaction between the two, along with a description of what I want out of pads for my car. Performance on the track; daily driving street manners; and LONGEVITY. I chose a company which I do not want to name at this time as I have only the 1 track day so far. If what I experienced (a friggin' dream) holds up for a couple of more I will name them. They are a US company (quick turnaround and no overseas shipping delay problems) who make only race pads, and they have been doing it for over 20 years for professional race teams and individuals alike. They have been great to work with and very supportive. They decided on 2 different compounds for the front and rear, and will make adjustments in the future as may be needed or desired by me. I am posting this now to let people know that a solution is probably possible, and who knows, maybe even before the "H" series is released.

The pads: Carbon Ceramic / Backing plates are 4.5mm thick and made of SS, no attachment points for pad wear sensors / Front compound 15mm thick / Rear compound 12mm thick (this will be increased when reordered)

My experience: 7 sessions / 126 total miles / 100 total minutes

Front pad material used: 0mm - no measurable wear
Front pad material remaining: 15mm
Rear pad material used: 0.5mm
Rear pad material remaining: 11.5mm

NVH Street: A soft swooshing or rubbing sound when braking at low speeds - easily tolerated. Squealed only twice briefly and lowly when backing up.
NVH Track: Not noticeable, and who cares anyway.

Rotor wear will take time to be determined, but given the low level of NVH I have hope. The company claims that their compounds are the most rotor friendly in the industry.

I did, and replied just now, thanks 🙏

I think 7 x 15 min sessions gives you lots of opportunity to cool brakes, and keep wear down.

When I ran 2 x 60 min sessions I wore my fronts to the plates quickly. Heat is the factor there. I
Clearly need to manage heat buildup better to get more longevity, but its hard when you're working on something and chasing lap times..

My brakes smoke when I'm in the hot pit not moving, so i don't make that a habit, cause i dont want to crack a rotor.

Just lighting money on fire here…

[ATX_M3]

Love to hear there's a glimmer of hope for the braking issue(s) with the G80….

This thread has been a roller coaster of emotions as I'm living vicariously through y'all tracking your G8x while my mid-November build is still sitting in QC (different topic, I know). Thanks to everyone posting here on what could be a solution for tracking a moderately heavy car with a ton of power and teeny weeny rear brakes.

Once the brake wear solution gets in place, we'll only need to figure out the limp mode and the windows rolling up on their own….not sure if I'm more or less confident in the ability to correct the software issues.

[spicoli024]

@Boomer2019 Appreciate the valuable feedback and information; thanks for putting it out there! Do you have to have M ceramic brakes for this solution or are you simply saying this company’s pad solution is a ceramic compound?

[Boomer 2019]

Originally Posted by spicoli024

@Boomer2019 Appreciate the valuable feedback and information; thanks for putting it out there! Do you have to have M ceramic brakes for this solution or are you simply saying this company’s pad solution is a ceramic compound?

Cast iron brakes for me, and the pads are a proprietary carbon ceramic material. No metal in the compound hence less rotor wear. I have no idea how the carbon ceramic brakes on these cars perform on a track longevitywise. I think that the number of people who frequently track their cars equipped with carbon ceramic brakes (regardless of make and model) is very small. Too many bucks for too little bang.

[spicoli024]

Originally Posted by Boomer 2019

Cast iron brakes for me, and the pads are a proprietary carbon ceramic material. No metal in the compound hence less rotor wear. I have no idea how the carbon ceramic brakes on these cars perform on a track longevitywise. I think that the number of people who frequently track their cars equipped with carbon ceramic brakes (regardless of make and model) is very small. Too many bucks for too little bang.

Agreed. Please do let us know if and when you are comfortable sharing the company, but I am pretty sure I know what "stuff" you're talking about.

[Boomer 2019]

Originally Posted by spicoli024

Agreed. Please do let us know if and when you are comfortable sharing the company, but I am pretty sure I know what "stuff" you're talking about.

Bzzzt... wrong cowboy. It ain't "stuff". Sorry, I'm still in "Die Hard" mode from the holidays.