[mid-corner fun]

I was having a bad day today, I somehow managed to cook a set of brand-new DTC70s (as in pads are now white color) & split a guiding pin. So here I am trying to salvage the situation, going out late on session 3 and I forget to turn off traction control. I've been keeping logs on my settings for 2+ years, this is the first time I forgot.

Very easy 1st lap testing the brakes, water/oil temps low and on the very first time I open the throttle, limp mode. Pit in, restart, half a lap later at the uphill (complete traction loss, as expected), limp mode. %$#@$@$!@#@#%@# and this one stayed on, wouldn't go off after restarting the car. Since this was a 1-day event I had decided to not bring my laptop and BT cable so I limped home, reset adaptations and the limp mode disappeared.

Freaking traction control strikes again



PS. Another option: One of the calipers was dragging due to the broken sliding pin, I'm wondering if traction control detected different rotational speeds between left/right wheels and caused the 1st limp mode? hmmm.....

[Killerfish2012]

I run crossed drilled rotors, and regular textar pads, and I've never cooked them at the track. Crossed drilled rotors are the key to keeping your brakes cool. As for your limp issues, they might be tune related, as I've never experienced this. My tune raises boost via a T-map(?) sensor, and therefore never messes with the ecu. with the max setting I am able to run 12.7psi. If you want to run more than that at the track, you might just want to do a complete flash tune, like GIAC. I think their stage 2 race tune, has just been released.

Good Luck.

[mid-corner fun]

Tune has nothing to do with this, it was off on that session as I was concentrating on dealing with the brake issue. It's DTC detecting excessive wheel spin or speed differential. Unfortunately none of that info shows up on the ECU and DSC logs but I'm sure it has to be stored somewhere else.

[wonho]

Peter, you need a new car already. You gotta put your issues with the current car behind you and start fresh. And I mean something completely new, not even the M3.

[turugara]

Originally Posted by wonho

Peter, you need a new car already. You gotta put your issues with the current car behind you and start fresh. And I mean something completely new, not even the M3.

+1

Noob question:
Why does TC induce limp mode?

[mid-corner fun]

short answer: unknown. There are a couple of similar 135 incidents reported on bimmerforums too but no one knows exactly what triggers this.

[DSC_OFF]

Don't recognize this track, is this lime rock?

[mid-corner fun]

Originally Posted by wonho

Peter, you need a new car already. You gotta put your issues with the current car behind you and start fresh. And I mean something completely new, not even the M3.

Good idea! I'll be coming around collecting donations soon

[mid-corner fun]

Originally Posted by DSC_OFF

Don't recognize this track, is this lime rock?

yep

[Autobahn335i]

Hmm very weird that you get a limp mode on 1st WOT in the session. There's definitely something wrong with your car

BTW the wheel speed sensors are located in the wheel hub. So anything brake caliper related should not influence this weird problem if you suspect the speed sensors.

[mid-corner fun]

Originally Posted by Autobahn335i

Hmm very weird that you get a limp mode on 1st WOT in the session. There's definitely something wrong with your car

BTW the wheel speed sensors are located in the wheel hub. So anything brake caliper related should not influence this weird problem if you suspect the speed sensors.

Not weird apparently, starts to make sense now that I reproduced the problem at home.

I don't know if the broken guiding bolt or the overheated pads came first. One of the 2 caused the other to fail and triggered constant rotor friction on the left side. There was no vibration but the rotation was not as free as the right side. With that setup in place, leave TC on and go WOT, instant limp mode. Repeat with TC off (even middle setting is fine) and the car just veers to the friction side as you'd expect.

Add a problem (pads overheating/broken guiding pin) to a driver omission (forgot to turn off DTC) to a built-in safety (DTC) and there goes a track day.

[Autobahn335i]

Interesting. I wouldn't have suspected that such a problem would cause a limp mode, rather some brake problem/DTC warning. Would make better sense

[mid-corner fun]

Agreed. this wouldn't be the first thing that doesn't make sense in this car...

[Autobahn335i]

Speaking of the devil, I experienced a similar problem at the track this morning Drove with DTC and the track was a bit wet the first session. This resulted in quite some traction control intervention and eventually I got a limp mode!

Had to drive in the pits to shut-off/restart and drove the rest of the session with DTC fully off. Wicked! Was the first time I experienced this.

[neilvosko]

What About oil cooler to keep the temps low, especially in the summer heat.

[Autobahn335i]

Originally Posted by neilvosko

What About oil cooler to keep the temps low, especially in the summer heat.

Check my sig

Dual oilcoolers, dual radiators... Still not enough cooling to keep water temps in check under all circumstances. I hope to get things fixed next season by adding an external transmission cooler.

[neilvosko]

wow, no kidding?



have you tried running it with e85 or meth? supposed to keep things cool.
especially with the turbo upgrade i see in your signature.

[nkadisha]

Have never gotten a traction control induced limp mode around the track, usually cooling related. Good luck finding a solution

[Autobahn335i]

Originally Posted by neilvosko

wow, no kidding?



have you tried running it with e85 or meth? supposed to keep things cool.
especially with the turbo upgrade i see in your signature.

I don't want to run meth although it could help a bit. However I'm confident that getting a separate tranny cooler is the solution: right now the transmission oil runs through a heat exchanger in the lower part of the main radiator. This helps to get water temps up after a cold start which is perfectly fine on a street driven car. But when racing, the hot transmission oil will heat up the coolant even further. Which is why the 6AT suffer a lot more from overheating issues on the track compared to 6MT cars.

[turb0mike]

Very bizarre to go into limp mode due to traction control issues. I have left mine on a couple times and just turn it off on long straights, lol. Good luck.

[neilvosko]

I've done that before, should definitely help