[S EyeLand]

Hi all,

I went catless and stage 2 today, BM3. Although it's still an absolute slug off the line with the torque nannies, from a 3rd gear roll the car is an absolute missile. The smell isn't too bad at all, but you can notice it when you're stopped with the windows open, oh well for that. I will still probably sell the car soon because of the launch issues. I don't want to flash the TCU and risk trans issues or bending a rod like BMW seems to think stock power would, but this definitely puts a smile on my face for the time being. It's like car turns in to a 1998 Toyota Corolla after mashing it off the line, fumbling though the gears making the throttle feel like the cable snapped (I know its electronic). I find it strange the F85 launched harder to 20 or 30 mph without any of that torque nanny nonsense, in spite of it being a far heavier vehicle. Is BMW being overly cautious? Or is their caution warranted to nerf the launch so significantly. Either way I'm now enjoying the car a little but still not enough to overcome the ridiculously poor launch. I've tried no DSC, all 3 shifting levels and MDM all of them have the limiter kick in.

[pbonsalb]

My 2018 certainly is not like that. I do have a trans tune but don’t recall the car bogging or being slow off the line before.

[S EyeLand]

Originally Posted by pbonsalb

My 2018 certainly is not like that. I do have a trans tune but don’t recall the car bogging or being slow off the line before.

I have to try the TCU tune, its exactly what happens in the Carwow m8 vs m5 race. skip to 3:00

[Holset]

Weird my car is a 21 Comp Lci and it spinn all 4 tires when launching so no torque limiters there.
About the Carwow video i think they fuck up the launch by standing in launch control mode for to long i think i it’s max 3 sec or 5sec.

[pbonsalb]

Did you buy the car new? If not is it possible a prior owner launched excessively and damaged the trans or triggered a reduced torque setting? Have you reset adaptation on the engine and trans ECUs?

Maybe try Xhp stage 1. I run stage 3 but mostly drive in Efficient mode with the trans in the lowest setting — for 99% of my driving, I don’t need more and the response is overly eager off the line in Sport Plud and transmission setting 3.

I have never used launch control in the nearly 30k miles I have had the car. I have not felt the need but will get around to it now that I have more time and plan to do some dragy testing and dragstrip runs.

[S EyeLand]

Originally Posted by pbonsalb

Did you buy the car new? If not is it possible a prior owner launched excessively and damaged the trans or triggered a reduced torque setting? Have you reset adaptation on the engine and trans ECUs?

Maybe try Xhp stage 1. I run stage 3 but mostly drive in Efficient mode with the trans in the lowest setting — for 99% of my driving, I don’t need more and the response is overly eager off the line in Sport Plud and transmission setting 3.

I have never used launch control in the nearly 30k miles I have had the car. I have not felt the need but will get around to it now that I have more time and plan to do some dragy testing and dragstrip runs.

Yup i bought it used. I think the trans is fine but it's sldo possible its worn/damaged but unlikely. Seems more like software intervention rather than a mechanical issue. I'll try stage 1 which notes the only changes being the removal of the torque limitations I'm just wondering how safe that would be for longevity. There's another thread where a member is asking about the stage 1 TCU tune, hopefully someone with stage 1 experience opines. I'm worried BMW sees these transmissions as weak points and has measures in place to cover this.

[pbonsalb]

But why doesn’t everyone complain if it is just stock torque limiting software? Yes, there is such software, but your complaint is one of very very few I have seen in the past 3 years. I would first find out if your car has an issue. Have you driven other M5?

I don’t worry about the trans tune. These are robust transmissions. 8HP75 has been around for a while and is well proven. The engine software also limits torque as does the software in most tunes. I use Stage 3 on the Xhp; I have never used drag race mode but not because I worry. Rather, I don’t feel that I need it.