Going built engine

[fstbtstr]

How far is it possible to go with stock DME for traction control/DSC with a clutched diff? Staged boost targets by wheel angle like Chevy does with the Corvette and clever braking by the old ediff module?

Would probably need better brakes.

For something like this, you probably want to limit the torque output while keeping the boost, right? I can't speak with 100% confidence for the N54 as that module is implemented in the Siemens layer, but S/N55s do have a BMW module which limits the output torque depending on the steering wheel angle. In stock form, this limitation is only active up to about 3200 or 3600 rpm, but this is defined in calibration and can be changed, just like the steering angle-based torque limit maps.
I guess carabuser can take a look at the N54 bins and see which Siemens layer var gets written to Mdk_rad_begr. Though N54 might not have this logic available.

 

[carabuser]

Mdk_rad_begr is in the N54 logic, but not used.

The steering wheel angle is taken into account by the DSC, so the DSC will reduce timing more aggressively when it detects steering input. That's one of the things that annoys me most about the MK60 DSC in the 335i, the unit in the Z4 lets you push more when the wheel is turned.

 

[fstbtstr]

Mdk_rad_begr is in the N54 logic, but not used.

The steering wheel angle is taken into account by the DSC, so the DSC will reduce timing more aggressively when it detects steering input. That's one of the things that annoys me most about the MK60 DSC in the 335i, the unit in the Z4 lets you push more when the wheel is turned.

I see that it's accessed in MDDMK to determine "fast path" torque limitation, just like in MEVD17.x. Sounds like in MSD8x it just gets some dummy value in Siemens layer like you said, and logic got more complex in later DMEs. I started to notice torque limitation via Mdk_rad_begr when I flashed xHP to my 6hp when all transmission limits were pretty much removed.
When you get that annoying DSC intervention, do you observe limitation via Mdk_asr_s only or do you also get limited by Mdk_asr_l? I find that when it starts to intervene via Mdk_asr_l, it closes the throttle and it gets choppy.
Does flashing 335i DSC with M3 firmware help or does it create more issues?

 

[carabuser]

I see that it's accessed in MDDMK to determine "fast path" torque limitation, just like in MEVD17.x. Sounds like in MSD8x it just gets some dummy value in Siemens layer like you said, and logic got more complex in later DMEs. I started to notice torque limitation via Mdk_rad_begr when I flashed xHP to my 6hp when all transmission limits were pretty much removed.
When you get that annoying DSC intervention, do you observe limitation via Mdk_asr_s only or do you also get limited by Mdk_asr_l? I find that when it starts to intervene via Mdk_asr_l, it closes the throttle and it gets choppy.
Does flashing 335i DSC with M3 firmware help or does it create more issues?

I haven't actually logged it, but it seems like Mdk_asr_l with throttle restriction.

It's only really an issue on roundabouts which we have a lot of here, when exiting and easing in the pedal it's way to eager to cut power, but once the wheel is straight it's fine.

Not tried flashing the M3 DSC since it requires a different wiring layout, but when the traction control is in the halfway mode the problem doesn't happen. It doesn't happen at all in my Z4, gives me much more freedom with the DSC fully enabled.

My plan is to get a DSC module for my bench and start disassembling the logic and see what I need to do to flash modified files to it. Ideally I'd have the M3 DSC flash, but modify it to work with the 335i wiring for the DSC button. That seems a lot easier than retrofitting the Z4 DSC unit to the 335i then trying to get it to work with all the other modules.

 

[ShocknAwe]

Sounds like we need a plug and play DSC module solution. I'd be willing to help fund this.

 

[carabuser]

Sounds like we need a plug and play DSC module solution. I'd be willing to help fund this.

For drag builds maybe there are improvements to be made, but for normal driving the BMW systems are pretty good. It's just they set the 335i DSC up to be safe when all systems are active.

Turning the DSC into DTC mode does the job, but I'll put some time into playing around with the DSC to see if I can relax things when DSC is fully on. I can get a DSC module for £12 on eBay so will have a play.

I did read through several topics about it all. There's a really good one on here about coding M modules and another on E90post about coding the DSC, but both leave things unresolved.

 

[fstbtstr]

Not tried flashing the M3 DSC since it requires a different wiring layout, but when the traction control is in the halfway mode the problem doesn't happen. It doesn't happen at all in my Z4, gives me much more freedom with the DSC fully enabled.

if wiring is the only issue, this sounds like the easiest way to solve this issue

 

[ShocknAwe]

For drag builds maybe there are improvements to be made, but for normal driving the BMW systems are pretty good. It's just they set the 335i DSC up to be safe when all systems are active.

Turning the DSC into DTC mode does the job, but I'll put some time into playing around with the DSC to see if I can relax things when DSC is fully on. I can get a DSC module for £12 on eBay so will have a play.

I did read through several topics about it all. There's a really good one on here about coding M modules and another on E90post about coding the DSC, but both leave things unresolved.

Sort of what I mean though. It's inherently safe, but for me when DSC cuts in on the short E82 it's profoundly violent and has resulted in some off throttle oversteer which is... Fun. This is with a clutched diff and ediff codes out. I massively prefer DTC. I really prefer MDM on cars I've driven. What Id really love to have is something like DTC at start with MDM available on one press, off on long press.

Happy to help

 

[Jern54]

Does your car have wood trim by any chance

Hahaha no I'm not Chef if you might think that.
E91 chassis here

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