Sorta pissed

[JonnyM3]

Went to the track today only to realize me LC wasn't working. Everytime I'd get to the line I'd engage LC and rev the car, but then it would start rolling. I don't recall the car doing this before. Due to this my times were shot I basically had to just rev the car out in first any pray I'd hook up when it went, which it never did. I ran a 13.0 at 110 and I'm goin back for a better time Friday if anyone can help me fix my LC

[mgx]

this shit was happening to me too, DONT follow through on the launch if you notice the car is moving. the tranny will overheat and will require you to turn off the car before you can use it again :/

[JonnyM3]

What did u do to fix it? Thanks for any info bro

[mgx]

tried 3 times that day to use LC all 3 times no dice and got critical tranny and temp warnings on my idrive. went home and tried it again the next day and it worked like a charm.

i noticed that on my first 3 attempts i was not pushing the gas past the resistance point and i think that may have been what caused it because the next day i did push it past the resistance point and the car launched perfectly

[JonnyM3]

I was to the floor with it. Idk man hope it starts working again.

[M3Fool]

I have never used LC before, but I do recall reading somewhere that you can only do it a certain number of times....... if that is the case, maybe you went over the limit???

[CarForHire]

Originally Posted by M3Fool

I have never used LC before, but I do recall reading somewhere that you can only do it a certain number of times....... if that is the case, maybe you went over the limit???

That's for the GTR isn't it?

[akh23456]

Originally Posted by M3Fool

I have never used LC before, but I do recall reading somewhere that you can only do it a certain number of times....... if that is the case, maybe you went over the limit???

sorry but i think your wrong, the M's don't have any limit for LC.

[1sikbmr]

Flame suit on- should have gotten a 6MT

[mkoesel]

Originally Posted by AudiS5

Went to the track today only to realize me LC wasn't working. Everytime I'd get to the line I'd engage LC and rev the car, but then it would start rolling. I don't recall the car doing this before.

If you are not on a flat surface, the car's gonna roll. As you know, you have to have your foot off the brake to get LC to engage, and there is no automatic mechanism that keeps you from rolling forward. It doesn't sound like there is anything wrong with your car, it was just the track. If you go try and do a launch with LC on a flat stretch of road today, it will most likely work fine.

But yeah, it's too bad BMW's LC implementation for the M3 does not let you hold the car with the brake. As I recall it, they made the LC for the 335is simpler, though I don't remember if you can use the brake or not. Hopefully the M5 and future implementations allow you to hold with the brake using your left foot and launch it by simply letting off.

[JonnyM3]

Track was very flat and it happens to me on the streets too. I've used LC all but 3 times due to the rolling. The car is actually rolling from being revved, not from a decline in te road.

[mrkbbd]

my car will engage launch control with the brake on, the other day I had the DSC off and was in S6, at a downhill light and just had my hand on the shifter, pushing it forward and the flag came up, so it may work with the brakes on

[mkoesel]

Originally Posted by AudiS5

Track was very flat and it happens to me on the streets too. I've used LC all but 3 times due to the rolling. The car is actually rolling from being revved, not from a decline in te road.

I know what you mean, but I've held mine at 4.5k (or whatever the initial RPM is) for 10 seconds or more with no movement whatsoever. So, yes the car will stay still if everything is just right. But I agree that it doesn't take much as far as surface imperfections for the rumble of the engine to set it into motion.

[mkoesel]

Originally Posted by mrkbbd

my car will engage launch control with the brake on, the other day I had the DSC off and was in S6, at a downhill light and just had my hand on the shifter, pushing it forward and the flag came up, so it may work with the brakes on

Very interesting. Just out of curiousity, when's the last time you had a software update?

One question that immediately comes to mind is - what will it do if you let off the stick, but keep your foot on the brake? Brake stand?

[persian54]

Originally Posted by akh23456

sorry but i think your wrong, the M's don't have any limit for LC.

There is...

the computer won't let you do it too much if the tranny starts to overheat

[JonnyM3]

Thanks for the help guys, just to clarify though, the car shouldn't move in LC right?

Hold DCT gear up while in M mode traction off in S6 wait for flags, foot to the floor, let it rev up then bring the DCT gear back for the launch correct? Cause whenever the flags come up, regardless how flat the surface I'm on the car starts to creep forward with the flags on.

[mkoesel]

Originally Posted by AudiS5

Thanks for the help guys, just to clarify though, the car shouldn't move in LC right?

Not necessarily correct, no. Remember, with LC the car is sitting there with the clutch/es open and no brake applied. It can easily roll.

Here's something to try: stop at your desired "launch site", put the car in neutral, and rev it to 5k RPM or so. Does it roll? If not then it will probably stay put if you try to use LC right there too. If it does roll though, then it probably won't stay put with LC either. Just a thought.