Track Cars & Brake Issues

[lynchy73]

Thank you for sharing!

So to ultimately turn it off, did they have to flash the ECU or something, or did it go back off on it's own again once temps cooled?

I called our "local" shop and they said check all of the things I already checked, primarily sensors.... but then they said check my brake fluid and ensure my axles are tight........ buddy, I feel like I could tell if I had loose axles lol. I lost a bit of faith with that response.

Can’t see it being anything to do with brake fluid. Maybe a local shop could try to monitor each wheel speed signal and slowly rotate the wheel, see if any are not switching. My guess is you have a bad wheel speed sensor or 2.

Correction to what I said earlier, the brake temperatures are estimated, not measured values (Lotus diagnostics can display that estimated number). So if you upgraded the brakes and cooling, the estimation wouldn’t change but the actual brake temperatures would be lower. My brakes still seem fine when the warning occurs.

Lotus didn’t do anything in my case. The warning in my case is just an algorithm that determines the brakes are hot and traction control is unavailable (in Sport mode), even if it really is… I guess the car estimates the rear brakes are hot and therefore have limited ability to control slip if TC intervenes. Track mode has less intervention and higher thresholds, so you don’t get the warning, or maybe it happens but at a higher estimated temperature (trying to find that out).

Long and the short of it, in my case, it seems there are no hardware or signal issues, the warning is just software generated based on the use case.

I can get the warning to occur pretty quickly, maybe 2 mins of super aggressive acceleration, immediate emergency braking, repeat, repeat with no delays.

 

[lynchy73]

So here is a screenshot of the lotus diagnostics, including the estimated brake temperature (translated from Chinese to English)

 

[Savanna7]

Very interesting. So in theory, the systems should still function correctly, but based on perceived temperatures, it's warning that they won't be as effective, and thus, full potential has been theoretically "disabled?"

 

[lynchy73]

Very interesting. So in theory, the systems should still function correctly, but based on perceived temperatures, it's warning that they won't be as effective, and thus, full potential has been theoretically "disabled?"

I don’t know how it actually works, but yeah, their estimate is based on the performance of the standard discs/pads and whatever cooling comes as standard. So yeah, if you upgraded discs/pads, cooling or even callipers, then the’d run cooler, the limits of the brakes would increase and the’d have the ability to run at higher temps, but the car still thinks it’s running the OEM setup and give the same warnings.

I’d be surprised if the car would actually turn off traction control when it determines the brakes are too hot. More likely the car functions as normal but the algorithm will expect the ability of the rear brakes to limit slip is reduced, so you get a warning that TC is unavailable. The V6 has a proper LSD, so the algorithm will be different so I doubt you would get that traction control warning. Good thing you can just select track and the warning goes away (it might come in at a higher estimated temperature).

 

[kitkat]

Interesting that there's a calculated brake pressure, I want that for datalogging.

 

[Savanna7]

I just went out for about an hour in all modes and nothing seemed to make a difference to my warning messages. I clearly have something else going on here.

Something I did notice however, is that the traction control button in Track mode has disappeared. I'm guessing because it has been "disabled" but kind of surprised that the button no longer shows on screen.

 

[mr.suntorytime]

have not run in to this issue and im sure kitkat would agree that there might be something wrong with your car @Savanna7

 

[Savanna7]

I agree. No doubt

 

[OppositeLock]

Wow, interesting. I used to have a Ford Focus RS as a daily driver, and they had this same sort of issue with their wet-clutch based rear differential. It would algorithmically decide that you've gotten it too hot, and it would disable the rear wheel power, and no amount of cooling or would fix it, since there's no sensor, it's all computed.

I wonder if more finesse with throttle control can make this problem less likely, because it's using the brake to avoid inside wheel spin. I know it's no fun when you're used to the system working, but as an experiment, try adding full throttle later when coming out of turns; like we used to do before the modern drivers' aids.

 

[Stella 凛]

I’ve never had an issue with TC in the V6. my front rotor paint indicated I peaked 800C on track, so 600C is a pretty low threshold, especially at longer braking zones.

Just run track mode

 

[Ft.S]

So, it seems we found the problem and it’s not actually a problem/fault after all….

So….. apparently there are temperature sensors in each brake or some part of them. If the temperature exceeds 600degsC in Sport mode, the traction control temporarily unavailable is displayed. It seems like it’s an automatic thing and it is not a fault. If you set to Track mode, the warning immediately disappears, switch it back to Sport, and the warning is active again. I had Lotus Tech in the car whilst I did multiple full acceleration, full braking cycles and they were monitoring various parameters.

I tend to use Sport mode, rather than track mode on track, but with all the avoidance stuff turned off. In future, I know to use Track and if I use Sport, I know that warning isn’t a big issue.

This is similar to what I experienced while driving normally on the street, and I have a V6. Mine was related to the parking brake not disengaging properly on the right side. As the parking brake caliper stayed closed, it generated sufficient heat and brake fluid boiling over the course of 30+ min. drives and 3 months that one time a red error message popped up on the dash indicating that the ESC requiring service and it being disabled.

That moment I switched to track mode, and completely disengaged ESC and turned off the car and restarted it after 3-5 mins. It did not happen again. However, I took it for service, there was a code registered, and brake fluid was down by nearly 1/3 with lots of air in it. They did two complete flushes of the fluid, Lotus UK recommended VDDM module firmware update and other software updates. Now it appears to be operating fine, its been two weeks.

Original post on this is here.

 

[Savanna7]

This is similar to what I experienced while driving normally on the street, and I have a V6. Mine was related to the parking brake not disengaging properly on the right side. As the parking brake caliper stayed closed, it generated sufficient heat and brake fluid boiling over the course of 30+ min. drives and 3 months that one time a red error message popped up on the dash indicating that the ESC requiring service and it being disabled.

That moment I switched to track mode, and completely disengaged ESC and turned off the car and restarted it after 3-5 mins. It did not happen again. However, I took it for service, there was a code registered, and brake fluid was down by nearly 1/3 with lots of air in it. They did two complete flushes of the fluid, Lotus UK recommended VDDM module firmware update and other software updates. Now it appears to be operating fine, its been two weeks.

Original post on this is here.

I missed this previously, but will be checking my fluid today. Thank you!

 

[mr.suntorytime]

Parking brake is fully electronic. No brake fluid.

 

[Savanna7]

Parking brake is fully electronic. No brake fluid.

No, but there could have been a fluid related issue according to the local dealer.

However, I just got done checking it and she's completely full and still looking fresh. I cleaned the electric connector as well (not that it should need it.)

 

[Savanna7]

Let’s GOOOOOOOOOOO BOYS!!!! Problem solved! Brake cleaner in the backside of the wheel hubs did the trick!

 

[lynchy73]

Let’s GOOOOOOOOOOO BOYS!!!! Problem solved! Brake cleaner in the backside of the wheel hubs did the trick!View attachment 85641

So nice when you finally solve 1 of those issues/problems that have been bugging you for ages. Had several of those too

 

[Savanna7]

So nice when you finally solve 1 of those issues/problems that have been bugging you for ages. Had several of those too

I was pumped. It took me a while to realize the lights were even off! I was driving around trying to uncover a noise I had been hearing when I eventually noticed less warning lights lol.

 

[EmiraSF]

I want to share a huge thank you to all the contributors to this thread.

After warping the hell out of my stock rotors lapping at Thunderhill in 106°, I replaced them with GiroDisc rotors (along with Motul fluid) in light of the advice shared in this thread. Yesterday I beat my PB at Sonoma by more than 4 seconds, in part due to very strong braking performance throughout the (very warm, though not as hot as Thunderhill) day.

One of the coolest facets of owning an Emira is the great community of folks building a knowledge base around these fantastic cars. Thank you all!

 

[Savanna7]

I want to share a huge thank you to all the contributors to this thread.

After warping the hell out of my stock rotors lapping at Thunderhill in 106°, I replaced them with GiroDisc rotors (along with Motul fluid) in light of the advice shared in this thread. Yesterday I beat my PB at Sonoma by more than 4 seconds, in part due to very strong braking performance throughout the (very warm, though not as hot as Thunderhill) day.

One of the coolest facets of owning an Emira is the great community of folks building a knowledge base around these fantastic cars. Thank you all!

I skillfully warped my Girodiscs too .
Me - 2, Rotors - 0

 

[BruceN]

Looking for those that track their Emiras frequently…..

I’m having brake issues that aren’t fully making sense to me. This happened with the factory pads for the initial shake down, and now the EBC RP-1s. I’ve read every brake thread I can find with no definitive answers.

Essentially, I can get about 3 great laps where everything feels exactly as expected. By the 4th lap, the brakes go from consistent and smooth to, inconsistent and “chunky” almost as if they are pulsing, or the pad material themselves are experiencing degradation and build up, but I would say it’s definitively not an ABS issue.

I’m currently running the factory Cup2s and have Motul 660 fluid already installed as well.

1. Due to it consistently happening within 4 laps, it sounds like a heat soak issue, but the brakes never get soft or mushy.

2. Based on number 1, it then leads me to think about heat based warping of the rotors and/or I read a thread about the parking brake getting involved once hot. If that were the case you would feel this all of the time after that initial saturation I think.

3. If it were air in the line, this would create a similar outcome to number 1 with a feeling of inconsistent pressure or mushy pedal, not the feeling I’m experiencing.

4. I could install brake ducting (and probably will), but I still think I would experience a brake “fade” issue rather than the feeling I’m getting when hot.

I was hoping I had a few loose lug nuts or caliper bolts that were allowing too much “flex” and a simple bolt check would solve the problem, but that has not proven to be the case.

Multiple people drove my car and felt the same sensation regardless of their pace. It was always on the 3rd or 4th lap. Each driver is very experienced in tracking and racing. One even owns a shop.

Is anyone else experiencing this? If so, how did you fix it? My next steps are trying a different set of pads and rotors while adding ducting, but that seems like an expensive game of chase, and I believe I read that at least two others had similar issues. Any help you can provide before I go down the economic rabbit hole would be helpful.

Thank you!

So I couldn't stand the RP1s - didn't like them on track (tough warm up), and didn't like them on the street. I was also having braking issues with other pads and significant decrement in performance after several hard laps. Probably heat soak in the brakes? What made a huge difference was getting the Girodisc rotors. I've had no significant issues since moving to them. Using the Pagid pads from GRP which I really like both on track and on the street. So I'd be curious if your issues go away if you moved to Girodic rotors.