Who's done the most DCT Launch Controls? Any problems?

[NetBoy]

Anyone done a lot of launch controls? Any issues (clutch, tranny) besides no rear tire tread

I'm wondering how the DCTs hold up. My old SMG fried the clutch at 40k miles and 10 launches. I know they are completely different systems but just curious.

[dillon733]

dont worry, the car is made to launch. I wouldnt do it every day of like 10 in the period of an hour but a couple times a month is fine. Make sure the location is safe then launch away!
Have fun be safe.
Launch Control FTW.

[boostitup28]

I launched mine for the first time last night and did a pretty serious burn through the entire intersection. This morning i was sitting in traffic and basically not moving and that engine malfunction/reduced power warning came up and gave me all sorts of problems so now my car is in the shop getting the idle control valve replaced tomorrow. I doubt that the launch is the fault to all this but just my experience.

[KMIII]

I would really like to know as well. Every time I think about LC, I think about how tough it would be on the transmission and all the different parts, so I refrain from using it. Think I should change my mindset?

[mkoesel]

I've probably used LC a couple dozen times or so.

Honestly, I doubt LC is that much harsher on the transmission than just flooring it in S6 with DSC off without using LC. I've done that a fair number of times also. Of course, that begs the question, just how durable is the DCT transmission in general. My feeling is that it is probably roughly as strong as the manual tranny car, and that the clutch-pack should last just as long as a manual transmission clutch as well. That's just my guess though.

[quackbury]

My understanding is that some other manufacturers with launch control are denying warranty claims when the trannies need to be replaced. Forget if I saw the thread here or on another board.

It will be interesting to see how BMW handles it if/when frequently launched DCT's start blowing up......

[dcstep]

Speaking as a 6MT that routinely does 6 to 10 lauches at the average autocross, I don't see why it should be hard on the car so long as you're launching on average pavement with street tires. The 6MT will spin the wheels with what seems like very little stress on the clutch and then I modulate spin with the throttle. I don't see why the DCT would be any different.

I do remember reading that the DCT launches at like 5000 rpm. That's way too high for the 6MT, unless you ride the clutch or immediately back out of the throttle. If the DCT is slipping the clutch to make up for the ultra high rpm, then I'd probably want to launch with ESC off, in manual mode and control wheel sping with my foot, or let MDM control wheel spin. Slipping the clutch at that high rpm would be hard on the clutch if you did it back to back or even four or five times within and hour.

Those of you that have lauched your DCT, can you tell if wheel spin is controlled by the throttle or the clutch?

Dave

[Splinter4784]

Ive done around 20ish LC's

[Dascamel]

Originally Posted by quackbury

My understanding is that some other manufacturers with launch control are denying warranty claims when the trannies need to be replaced. Forget if I saw the thread here or on another board.

It will be interesting to see how BMW handles it if/when frequently launched DCT's start blowing up......

Thats on the Nissan GTR. Can't directly compare, it has far more torque and the car is AWD. The stress on the transmission and drivetrain is far more severe.

[MysticBlue]

Originally Posted by dcstep

Those of you that have lauched your DCT, can you tell if wheel spin is controlled by the throttle or the clutch?

Dave

I think it's the throttle. When launch is initiated, it starts with quite a thunk... it doesn't feel like there is any clutch modulating going on at all. It feels pretty much like a clutch dump, then EDC controls wheel spin with the throttle just like it would doing a hard start without using launch control, except the intervention level is a whole lot less than normal EDC and a little less than MDM... in other words somewhere between MDM and nothing. I don't know this for sure, but that's my impression from the half dozen launches I've done.

[mixja]

Did mine properly for the first time about 4 weeks ago, ever since I've had a strange problem where the car makes a sound like it is hitting the rev limiter under WOT in 1st gear only. You can also pick the sound up sometimes on a bumpy surface in 2nd gear, so I think this is a DSC sensor issue or similar....

[dcstep]

Originally Posted by MysticBlue

I think it's the throttle. When launch is initiated, it starts with quite a thunk... it doesn't feel like there is any clutch modulating going on at all. It feels pretty much like a clutch dump, then EDC controls wheel spin with the throttle just like it would doing a hard start without using launch control, except the intervention level is a whole lot less than normal EDC and a little less than MDM... in other words somewhere between MDM and nothing. I don't know this for sure, but that's my impression from the half dozen launches I've done.

If you're correct, then I don't think that DCT launch should be too hard mechanically on the car. Electronically, I have no idea.

Dave