Disabling DCS torque reduction for road course track tune

MrBlah

Specialist
Aug 31, 2019
62
13
0
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135i, 335i, x5d, r53
All the regular nannies are off, but I still have a DSC torque reduction on 3rd gear or higher sweepers where the steering angle is more than about 10 degrees. As soon as the wheel is straight it's like hitting NOS.

I know some get around this by disconnecting the yaw sensor under the seat, I would rather run a tune that turns off all the reductions requested by the DSC, I do this with my R53 mini's and it's similar simens code.

anyone done this? I suspect this section has something to doo with it

1665753267843.png
 

Shitrockn54

Private
Apr 17, 2022
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335xi
Its already defined in the new mhd+ xdfs. Asr is traction request and msr is anti skid roll i believe, id have to check the fd docs but can comfirm with both toggles off the traction light flashes and that is all the dme doesnt care one bit.
 

MrBlah

Specialist
Aug 31, 2019
62
13
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135i, 335i, x5d, r53
he
Sorry i don't have them defined on i8aos.
My winols computer isnt here to find them either right now. Maybe someone here can find them for you or can give the hex adresses for i8aos
hex in the damos I have is 02A18 not sure how to map that to the right hex address in my i8aos. I do not have a damos for i8aos or I would just make my own xdf file
 

Shitrockn54

Private
Apr 17, 2022
34
21
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335xi
he

hex in the damos I have is 02A18 not sure how to map that to the right hex address in my i8aos. I do not have a damos for i8aos or I would just make my own xdf file
U load another bin file(yours for i8aos) connect the 2 projects then highlight a few bits around the one u want because single bytes can be a pia then use the search in project on whatever is the opposite side of the damos u have. Find the match make sure they line up right click and hit transfer selected map. Then u have the beginning of a damos for your bin
 

MrBlah

Specialist
Aug 31, 2019
62
13
0
Ride
135i, 335i, x5d, r53
I think I understand now. On the sample I have ip_fac_vb_pwm_acr is at hex 02AD8. On my file that table appears to be at 042E70 I can then back up until I find Disable ASR interventions, on the sample damos its at 02A18
 

MrBlah

Specialist
Aug 31, 2019
62
13
0
Ride
135i, 335i, x5d, r53
Still no luck, I thought I had found it but 42E70 is not it, traction control still kicks in
 

hollracing

Private
Oct 26, 2022
35
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Still no luck, I thought I had found it but 42E70 is not it, traction control still kicks in
Theres alot more to DSC besides traction control (ASC).. A fair bit of ASC regulation is done with braking.. Do you have logging? Can you log the DSC Torque Request Status which is sent to the DME with the 2x DSC Torque requests? This would tell you what regulation/s you have :ASR/C, DSC, MSR ect. ect.
Although presuming the light on the dash is flashing when your experiencing this it’s likely ASC which started intervention so rear wheel/s about to slip... Theres dsc coding that can help the situation. But it would pay to understand why its intervening first. From what youve said when it happens: 3d gear sweeper so high lateral load, high yaw rate, with high engine torque, and so also some long load, at speed, and then also it only stops when steering angle is reduced… it could be any form or combo of dsc regulation (although probably not incl ABS or MSR..) But if you just want to reduce the peak amount of eng torq reduction during asc regulation change the DSC coding data for MOTOR and ASC_AMR_STB. Theres info on them in the update log in the ncs expert folder for e89.
Can you share/send DSC nettodat trace?
 

carabuser

Lieutenant
Oct 2, 2019
857
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UK
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Z4 35i & 335i
I've also felt that traction control gets too intrusive when you have any steering applied.

As @hollracing said, there'd a few different functions that can pull engine torque. Just looking at the DME you have anti roll (ARS), traction control (ASR and MSR) and longitudinal dynamics (LDM).

@MrBlah If you want to find what exactly is causing the power cut then you can add these logging parameters included in my attachment to MHD. Unzip the file and copy if to the MHD root folder. You can then select 6 extra logging channels that should be at the top of the list. If you do a log with those channels selected while the problem occurs then it should tell you what function is causing it.
 

Attachments

  • I8A0S_UserChannels.zip
    402 bytes · Views: 36

MrBlah

Specialist
Aug 31, 2019
62
13
0
Ride
135i, 335i, x5d, r53
light is not flashing as I have the dsc toggled off by holding the button

I would also turn off asr, ars and msr I dont need any of them on track, I need the addresses and setting to toggle though

I'm running jb4/meth so I cannot use mhd logging
 

MrBlah

Specialist
Aug 31, 2019
62
13
0
Ride
135i, 335i, x5d, r53
dsc files, i'm at the track this weekend, trying to drive around the tq cuts again
 

Attachments

  • WORK.zip
    960 bytes · Views: 20

hollracing

Private
Oct 26, 2022
35
36
0
To be having ASC intervention with DSC switched completely off (button held down/not DTC or DSC mode unchanged) is very strange / fascinating..
Again some form of logging or understanding of what is actually happening in your situation would save guessing.

Coding index would have been useful, but regardless I have guessed and made some changes to you NETTODAT for you to try.
Am I correct in guessing the vehicle is a 135i N54 Manual with no LSD and no Active Steering?
 

Attachments

  • NETTODAT.MAN.txt
    215 bytes · Views: 12

MrBlah

Specialist
Aug 31, 2019
62
13
0
Ride
135i, 335i, x5d, r53
Yes n54 135i I have a m3 rack but do not plug in the rack assist
 

hollracing

Private
Oct 26, 2022
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Ahh M3 rack! ok that’s starting to make, at least a little more sense.
I wouldn't think the Servotronic being non-operational is a contributing factor.

Its still strange and fascinating that this is happening in dsc off mode!?!
Is this a US Spec car by chance?

With DSC on mode or DTC I would be pretty confident in guessing the intervention being DSC (esp/stability control) and will assume for now it is the case for you although you have it in DSC off mode.
So probably not ASC/ASR intervention which might be explanation why the ecu changes for ASC/ASR weren’t effective...

The DSC controller expects a given amount of yaw - for a given steering wheel angle - at a given velocity. Or “steering characteristic".
As the m3 rack is “quicker” the measured yaw will be higher than what it is expecting for the measured amount of steering...
So, I'm guessing it assumes, as the measured yaw is higher than expected it is oversteering (lower would-be understeer).
This is quite a common complaint with retrofitted m3 rack, and I have wanted to test some coding changes that I would expect to effect this...

Are there any other modifications that would change the way in which the standard car behaves dynamically? wheels &/or tyres ect?

Attached is another NETTODAT.MAN for you to try. I have discarded my last changes, I take it you didn't try that out?
In theory this should make at least a noticeable difference. It may not be a complete cure, I have made only 1x change to your original TRC, there are more options that can be changed that will likely affect this, but if we do them separately it will provide definitive results.

There is also scope in the coding I believe to enter parameters to define a custom steering characteristic model, but I don't yet understand them enough... yet. Alternatively, you could try load the DSCM80 .0pa as the 1M came already with that rack.
 

Attachments

  • NETTODAT.TRC - 2.txt
    215 bytes · Views: 10

MrBlah

Specialist
Aug 31, 2019
62
13
0
Ride
135i, 335i, x5d, r53
I did not have a chance to test the previous file you posted. The car is on 245 square with coilvers/camber and it's pretty low I get some bump steer

I thought the 1M DSC was a different module ? There were some retrofit posts, they use different brakes and possibly master cycl