Disabling DCS torque reduction for road course track tune

KClemente

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Took a log for anyone to check out. Full wheelslip with no throttle or ign cut

Also used @carabuser userchannels file.

 

AzNdevil

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42CD9 pretty much seems like the ASR toggle to me. Only TC works on the brakes now and the dme doesn’t cut the throttle or ignition during aggressive wheel slip. I’ll confirm ignition and throttle with a log, though I can get some mad wheel spin with traction control fully on

I really wouldn’t recommend turning it off on a street car as it pretty much cripples your traction control.

thanks for confirming. if the asr toggle location is right, i am 90% confident the msr toggle is correct as well... however, i will be honest and tell you guys upfront that i dont know how to test msr or get it to trigger

i totally agree with you wrt the second part, my mechanic almost crashed my car when he was testing it after an alignment because he expected tc to kick in and save his ass

if you guys have upgraded bbk with different calipers (eg. brembo ap f80 m, e9x m perf doesnt count, those are weaker than stock), you better play with dsc coding to adjust for the sliprate dsc kicks in as well... otherwise you might get a nasty surprise when the brakes grab, ask me how i know and dont say i havent warned you ;)
 
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KClemente

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Nov 26, 2019
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thanks for confirming. if the asr toggle location is right, i am 90% confident the msr toggle is correct as well... however, i will be honest and tell you guys upfront that i dont know how to test msr or get it to trigger

i totally agree with you wrt the second part, my mechanic almost crashed my car when he was testing it after an alignment because he expected tc to kick in and save his ass

if you guys have upgraded bbk with different calipers (eg. brembo ap f80 m, e9x m perf doesnt count, those are weaker than stock), you better play with dsc coding to adjust for the sliprate dsc kicks in as well... otherwise you might get a nasty surprise when the brakes grab, ask me how i know and dont say i havent warned you ;)
Do F30 (front only) brembos count? I’ve optimized the frm module for my M3 rack too, but still have to look around the dsc module for steering angle settings

I’ve also got a 2007 dsc module so no flashing an M3 software unfortunately
 

AzNdevil

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Do F30 (front only) brembos count? I’ve optimized the frm module for my M3 rack too, but still have to look around the dsc module for steering angle settings

I’ve also got a 2007 dsc module so no flashing an M3 software unfortunately
technically yes, piston area is different to the stock caliper by a bit iirc, also, different sized brake disc and thickness will make a difference as well
in reality, it is up to you to decide...unfortunately the parameter is most likely based on a lookup table of sorts so you cant fine tune it

i tested this a few years ago and they do make a difference, i just dont remember which is which but you can deduct from the options as different car uses different sized calipers and discs

easiest way to test this... disable asr and msr, leave traction control on and throw the car around
dsc will make the brakes grab.... its easier to notice the difference in wet/snow

1671175216910.png


as for changing how the brakes engage during understeering/oversteering conditions, you can play around with the below coding

understeering:
this can be tested with traction control on, give the car ~10-20% throttle and crank the steering wheel to do a 180 degree turn at 30-40kmh
if you have enough front grip and screechy race pads, you can hear your front brake calipers grab during cornering
1671176192926.png


oversteering:
crank the wheel, go wot and do donuts.....
1671175646145.png


for cars with a m3 steering rack retrofit, it gets more complicated since the dsc also monitors the steering wheel angle input
i noticed this when i was trying to do a quick u turn and traction control kicked on without the car actually understeering

the 1m/m3 dsc firmware offers difference choices, this can be seen from the coding options available
again, the parameter is most likely based on a lookup table of sorts so you cant fine tune it or copy it from m3 coding

since my dsc module doesnt support the m3 firmware either, the only way i was able to sort of workaround this was to dumb down the understeering coefficient

1671175433835.png


if you want to scientifically test this, there are custom channels that could be added in mhd to log individual wheel speeds, yaw sensor lat/long angles and brake pressure and so on, i have attached the xml files for IJ/IK/IN here..i dont have anything for I8... @RSL or @carabuser might be able to help with this

i think this info would be a great supplement to the m3 steering rack retrofit thread but i am lazy and busy ;)

getting a bit off topic so i will stop here...
 

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hollracing

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There is actually possibility to code a custom steering wheel characteristic curve in the versions (non-m) that allow a custom einspurrmodell… I haven’t quite figured out the meaning of the data for it yet. But its not 100% necessary for m3 rack conversion and associated premature intervention.. You can get it to work well enough with just changing the coding for the lenkwinkelkennlinie and delta-psi-beta limit correction.

The druckmodell parameters definitely do alter the balance characteristics like you say, and it would be logical that the coding values just tell it which predifned model to use, but im not sure atmo… often if theres a coding parameter that has a range of 0-7 this is often used for levels and from my limited testing it definitely seemed to work this way but I still think it’s likely that it just tells it which model to use and that theyre just likely arrange in an incremental order.

On non-m versions you can adjust through coding the amount of asc thats done through engine torque reduction (asc_amr) & braking (asc_bmr) separately.

While im at it: under/oversteer parameters… 0-1 is dsc, 1-2 is asc/abs, 2 is threshold.
The 2x gmr parameters are slopes in and out of intervention.
And the main difference between dtc & mdm is pre_usc 😉
 

NikolayBG

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Sep 11, 2022
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Hello @MrBlah, did you solve your problem with the torque reduction?
I have the exact same situation, the car has a huge reduction in torque when cornering, to the point where I can go full throttle in every corner without spinning, if the car skids due to a wet patch or slippery road, I get even more torque reductions until the car is straight.

Tried different DSC coding settings with no success

I am playing with the DME to solve this problem for quite a long time.

No difference after I played with:

logical constant inhibition torque intervention for safety

Torque after torque intervention to reset LV_TQ_LIM_INTV

ARS torque loss



I already disabled the ASR intervention but it only helped in a straight line, now I can spin my tires freely even with DSC on.

My car is auto so I keep the MSR on…

Suspension mods - lowered with BC coilovers, m3 control arms and 20mm wheel spacers – square setup.

Any suggestions what to try next?
 

hollracing

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Oct 26, 2022
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Hello @MrBlah, did you solve your problem with the torque reduction?
I have the exact same situation, the car has a huge reduction in torque when cornering, to the point where I can go full throttle in every corner without spinning, if the car skids due to a wet patch or slippery road, I get even more torque reductions until the car is straight.

Tried different DSC coding settings with no success

I am playing with the DME to solve this problem for quite a long time.

No difference after I played with:

logical constant inhibition torque intervention for safety

Torque after torque intervention to reset LV_TQ_LIM_INTV

ARS torque loss



I already disabled the ASR intervention but it only helped in a straight line, now I can spin my tires freely even with DSC on.

My car is auto so I keep the MSR on…

Suspension mods - lowered with BC coilovers, m3 control arms and 20mm wheel spacers – square setup.

Any suggestions what to try next?
What car? Even with DSC off?
 

hollracing

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Yep, that's the problem..., even with DSC off? The DME is MSV80, but it has the same definitions as MSD80!
What car? I don’t understand how you get dsc intervention with dsc off. I tried to replicate this originally in both an e92 335i (n55 dct) and m3 but I can’t get it to do it.
Do you have or can you log this happening that include st_dsc, st_clctr & the 2x torque request from dsc?
Can you share a nettodat coding trace from the dsc?
 

NikolayBG

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hollracing

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2007 BMW e92 328i
Its not US market by chance?
Same here...

Not sure how? Can this be done with Testo?
Not sure, but probably. I'm not sure how you'd do it. These signals are in the PTCAN messages from the DSC. I use arduino, kvaser or AIM.
Yes, I will send it to you.
Cool, I'll have a look.

If you want to try coding a few things yourself in the DSC?

To try and stop it intervening when DSC is off, try:
Turning CTC off.
Turning PRE_USC off.
Changing MOTOR to 0x00
Changing DELTA_PSI_BETA_LIMTITKORR to 0x01 or 0x00
Make sure Lenkwinkelkenlinnie is correct for your steering rack.

To try and make it less of a problem, try:
Changing GEAR_MOMENZTREGLER_MIN & GEAR_MOMENZTREGLER_MAX to 0x08
Turning FLR & CBC off.
Changing ASC_AMR & ACS_BMR to 0x00
 

NikolayBG

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Sep 11, 2022
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Its not US market by chance?
Canadian car, I think its the same as US market.
Not sure, but probably. I'm not sure how you'd do it. These signals are in the PTCAN messages from the DSC. I use arduino, kvaser or AIM.
Any DIY article, I would like to try
Cool, I'll have a look.
Will read the DSC in the weekend and send it to you, because now my Netodata file is empty
If you want to try coding a few things yourself in the DSC?

To try and stop it intervening when DSC is off, try:
Turning CTC off.
My DSC module in NSC Dummy is "MK60_87.C0A"
if you mean SDR_CTC, the default data is:: 00, so I should change it to 01?
Turning PRE_USC off.
the default data is: 00, so I should change it to 01?
Changing MOTOR to 0x00
This is in the "Dynamic cruise control (DCC) coding data", are you sure?
Changing DELTA_PSI_BETA_LIMTITKORR to 0x01 or 0x00
I already tried this in the past, no difference.
Make sure Lenkwinkelkenlinnie is correct for your steering rack.

never played with it, I'm sure it is in its default settings.​

To try and make it less of a problem, try:
Changing GEAR_MOMENZTREGLER_MIN & GEAR_MOMENZTREGLER_MAX to 0x08
Turning FLR & CBC off.
FLR is off, CBC: the default data is: 00, so should I change it to 01?
Changing ASC_AMR & ACS_BMR to 0x00
Again, this is in the "Dynamic cruise control (DCC) coding data", are you sure? I think those are active only when you are driving with cruise control. I think that is one of the reasons you cant turn on cruise control when driving with DSC off.
 

hollracing

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Canadian car, I think its the same as US market.
I'm starting to see a pattern...
Any DIY article, I would like to try
No, I can help you with CAN message setup if you had a CAN logger. I have an Arduino config I could share but you would still need some sort of data analysis software that would load log's in .csv for it to be of use to you.
Will read the DSC in the weekend and send it to you, because now my Netodata file is empty
Thank you, I have many, many traces to compare it to.
My DSC module in NSC Dummy is "MK60_87.C0A"
if you mean SDR_CTC, the default data is:: 00, so I should change it to 01?
0x01 is off
the default data is: 00, so I should change it to 01?
0x01 changes pre_usc to off, this is pre-under/oversteer control. With pre_usc and in DSC on or DTC, ASC intervention is when the car is heading towards wheel slip.
With pre_usc off and in DSC on or DTC ASC intervenes only once there is slip.
This is basically the difference between DTC & MDM.
Obviously, you have ASC intervention being ignored in your ecu but could be worth a try if all else fails.
This is in the "Dynamic cruise control (DCC) coding data", are you sure?
Yes, this is from the E89AEDOC file (coding index update file)
07.01.09 Li 09-03-510 DSC MK60_87.C0C [NF192.X, e] agilere ASC/DSC Regelung mit K-WORT ASCD bei N57 FZGen
(07.01.09 Li 09-03-510 DSC MK60_87.C0C [NF192.X, E] Agile ASC/DSC regulation with K-word ASCD at N57 FZGEN )
If you search MK60_87.C0C for order option ASCD you'll see motor changes from 0x0B to 0x0A with this option.
Change yours to 0x00 to test.
This would probably be my first test as this changes how the dsc works with the ecu.
I already tried this in the past, no difference.
Makes no difference... to your situation ;)

never played with it, I'm sure it is in its default settings.​

Perfect
FLR is off, CBC: the default data is: 00, so should I change it to 01?
0x01 is off this should be highly unlikely to effect your situation but worth a try if all else fails.
Again, this is in the "Dynamic cruise control (DCC) coding data", are you sure? I think those are active only when you are driving with cruise control. I think that is one of the reasons you cant turn on cruise control when driving with DSC off.
Again, yes. BMR adjsuts the amount of ASC done by braking and AMR by torque reduction. Set both to 0x00 as a test.
To be able to use cruise control with dsc off or atleast when in DTC try changing DCC_DTC (00300014 mask 0x40).
 
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NikolayBG

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I'm starting to see a pattern...
I was impatient and tried all the suggested coding, but no difference...
No, I can help you with CAN message setup if you had a CAN logger. I have an Arduino config I could share but you would still need some sort of data analysis software that would load log's in .csv for it to be of use to you.
I have the free version of "MegaLogViewer" and will buy the hardware you suggest . I would be very happy to setup a CAN logger and dig into the problem because it's working on my nerves for quite a long time. I have tried many things without any success.

In the DME I change this table to zero, which was promising but no difference either...
1677879959556.png
 

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carabuser

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You could use MHD to log some of the parameters posted here to narrow down exactly what is causing the power limitations. No need to mess around with DSC coding or guessing random OLS tables.
 

NikolayBG

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You could use MHD to log some of the parameters posted here to narrow down exactly what is causing the power limitations. No need to mess around with DSC coding or guessing random OLS tables.
@carabuser , my car is a 328i with n52 engine, there is no MHD for the N52. I wrote here looking for solution, because the OP had the same problem as me. Maybe a CAN Bus logger will be my best option as @hollracing suggested, but I don't know were to start with it, because its new to me.

I am checking this video now: BMW CAN BUS USB
 

carabuser

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Would be a lot easier for you to use DeepOBD. That will let you log on the N52.
 

hollracing

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@carabuser , my car is a 328i with n52 engine, there is no MHD for the N52. I wrote here looking for solution, because the OP had the same problem as me. Maybe a CAN Bus logger will be my best option as @hollracing suggested, but I don't know were to start with it, because its new to me.

I am checking this video now: BMW CAN BUS USB
You'll need to first figure out what style of logger suits your needs and then just get the one that suits your budget vs available time. Basically the more money you spend the less time and effort you'll spend getting it working. Lol.
A CAN logger logging PTCAN will let you see whats going on as a whole and should mean you can figure out where the intervention is coming from and why but won't (easily) let you log all the ECU parameters that an OBD type logger like suggested would.
If your interested in logging driving get a CAN logger.
If Tuning use an OBD logger
If CAN reverse engineering get a CAN - USB interface