[gpdriver17]

     Featured on BIMMERPOST.com

When I first got my car, using launch control, shifts to 2nd were seamless. I couldn't even tell the car shifted. I've probably done it a few hundred times now and anymore it shifts just like it normally would in auto mode. There's a noticeable delay going from 1st to 2nd gear.

This isn't just in my head, I have logs to back it up. Also dragy times. I noticed my 0-30mph times are the exact same as the used to be, so is 60-130. But 30-50 is about .3 seconds slower. 50-60 is also the same as it used to be. The result is basically that even with a JB4, 0-60 is right around 3.0 instead of 2.6-2.7 like it used to be. Also 1/4 mile times are up about .2-.3 seconds.

Does anyone know if BMW limits the number of times LC will work? Maybe to save the transmission? It still says "Launch Control Active" but it's not the same. Would a TCU tune address this?

[Resjudicata]

Originally Posted by gpdriver17

When I first got my car, using launch control, shifts to 2nd were seamless. I couldn't even tell the car shifted. I've probably done it a few hundred times now and anymore it shifts just like it normally would in auto mode. There's a noticeable delay going from 1st to 2nd gear.

This isn't just in my head, I have logs to back it up. Also dragy times. I noticed my 0-30mph times are the exact same as the used to be, so is 60-130. But 30-50 is about .3 seconds slower. 50-60 is also the same as it used to be. The result is basically that even with a JB4, 0-60 is right around 3.0 instead of 2.6-2.7 like it used to be. Also 1/4 mile times are up about .2-.3 seconds.

Does anyone know if BMW limits the number of times LC will work? Maybe to save the transmission? It still says "Launch Control Active" but it's not the same. Would a TCU tune address this?

if you updated your idrive software, I noticed a difference from the 11.2019.45 vs the new 07.2020.55 and 11.2020.50.

[limeypride]

Originally Posted by gpdriver17

When I first got my car, using launch control, shifts to 2nd were seamless. I couldn't even tell the car shifted. I've probably done it a few hundred times now and anymore it shifts just like it normally would in auto mode. There's a noticeable delay going from 1st to 2nd gear.

This isn't just in my head, I have logs to back it up. Also dragy times. I noticed my 0-30mph times are the exact same as the used to be, so is 60-130. But 30-50 is about .3 seconds slower. 50-60 is also the same as it used to be. The result is basically that even with a JB4, 0-60 is right around 3.0 instead of 2.6-2.7 like it used to be. Also 1/4 mile times are up about .2-.3 seconds.

Does anyone know if BMW limits the number of times LC will work? Maybe to save the transmission? It still says "Launch Control Active" but it's not the same. Would a TCU tune address this?

There's a launch counter and you've exceeded it. Instead of convulsing seamlessly between gears, I'd bet money you're now hearing a distinct crack at each shift... right?

I've posted about this many times—it's a thing. I burned through them on my M8 in about 3 months.

A TCU tune should address it—that exists for pre-LCI F90s but not for the later models nor for M8s.

The limiter is the transmission, not the engine/ECU.

[AHall]

Originally Posted by limeypride

There's a launch counter and you've exceeded it. Instead of convulsing seamlessly between gears, I'd bet money you're now hearing a distinct crack at each shift... right?

I've posted about this many times—it's a thing. I burned through them on my M8 in about 3 months.

A TCU tune should address it—that exists for pre-LCI F90s but not for the later models nor for M8s.

The limiter is the transmission, not the engine/ECU.

Good info LimeyPride. What are the effects at this point?

[limeypride]

Originally Posted by AHall

Good info LimeyPride. What are the effects at this point?

Nothing beyond the shifts but that slows down acceleration significantly.

[AHall]

Thanks but do the shifts eventually return to normal

[limeypride]

Originally Posted by AHall

Thanks but do the shifts eventually return to normal

The crack you hear is the sound from a normal high-load shift without launch control. So this is what you'd hear when you've exceeded the limit—this is the new normal. Short of a thus-far elusive TCU tune, there's no way I know of to restore LC's factory shift mode.

[gpdriver17]

limeypride Thank you! Confirms what I suspected, unfortunately. Are TCU tunes just like ECU tunes as far as warranty goes? The dealer can tell even if it's flashed back before going in? I'm getting really tired of dealing with this car. Strongly considering the model s plaid. 0-60 in < 2 seconds and 9.2 1/4 miles with a warranty. No e85/boostane/meth mixing.

[gpdriver17]

I talked to some others about this and found it is limited to 100. TCU Tunes don't appear to fix it, but help...

[limeypride]

Originally Posted by gpdriver17

I talked to some others about this and found it is limited to 100. TCU Tunes don't appear to fix it, but help...

Who said TCU tunes don't fix it?

[gpdriver17]

Originally Posted by limeypride

Who said TCU tunes don't fix it?

FSociety

[limeypride]

Originally Posted by gpdriver17

FSociety

But how does he know when there are no TCU tunes for an M8 yet? The implication is that there is now one available—is this from an ongoing thread?

[AHall]

Originally Posted by gpdriver17

I talked to some others about this and found it is limited to 100. TCU Tunes don't appear to fix it, but help...

100 for the life of the car?? This should be documented somewhere.

[gpdriver17]

Originally Posted by limeypride

But how does he know when there are no TCU tunes for an M8 yet? The implication is that there is now one available—is this from an ongoing thread?

I'm not sure. He mentioned it in the M5 whatsapp group chat.

[limeypride]

Originally Posted by gpdriver17

I'm not sure. He mentioned it in the M5 whatsapp group chat.

If you don't mind, could you ask? I'm not a WhatsApp user/fan. :

[gpdriver17]

He was speaking about the older M5's < 2020 MY.

[pcai]

Well, better start rationing launch controls .

[KoenG]

Originally Posted by gpdriver17

He was speaking about the older M5's < 2020 MY.

Like already discussed a few times before, as from 09/19 the ZF8HP75 was replaced by the ZF8HP76 which eliminated launch control issues. The M8 got the 76 trans from the commercial launch.

https://www.youtube.com/watch?v=RpGLqvgwtFM

[Trilogy_M]

I have a 21 M5C arriving in about a month. Will my LC be limited to 100 too?

[limeypride]

Originally Posted by KoenG

Like already discussed a few times before, as from 09/19 the ZF8HP75 was replaced by the ZF8HP76 which eliminated launch control issues. The M8 got the 76 trans from the commercial launch.

It still has the LC count limiter. I'm not sure of the relevance of your post. :

[limeypride]

Originally Posted by Trilogy_M

I have a 21 M5C arriving in about a month. Will my LC be limited to 100 too?

Yes, almost certainly... but what we already know today is based on community knowledge—no formal OEM acknowledgement of the restriction exists. So if they have removed the count limiter, they probably wouldn't say so.

[KoenG]

Originally Posted by limeypride

It still has the LC count limiter. I'm not sure of the relevance of your post. :

OP has an M5 with the HP75. They replaced it with the 76 which has stronger solenoids to assure trouble free 1st to 2nd shifts under full load. The 75 is not able to cope with the S63 launches.