A quick and easy way to street tune your CSL conversion for drivability.

[Obioban]

Wideband for this-- should we put it pre or post cat?

[Bry5on]

Do you use map sensor as kassel kit? When it installed on intake, or kit when it is installed near to ecu box? Or original csl tube for map?

I use a map sensor in the ebox area, connected to the brake booster hose

[Bry5on]

Wideband for this-- should we put it pre or post cat?

I run my wideband pre-cat, it’s most useful for the open loop WOT tuning

[Bry5on]

Update: Bank 1 long term fuel trim is 1.01 and bank 2 is 1.00 after turning adaptations back on. That’s as good as it gets!

[heinzboehmer]

Thanks a lot for this Pavlo! Just finished the warm tune and my car drives much better now. My car needed fuel in a lot of places (much like Bry5on's):



Rev matching is more responsive (have yet to get the engine to stumble like it sometimes did before) and the car feels a little livelier. Won't go as far as saying that it feels more powerful, but it does feel like it struggles less with around town driving. But by far, the most noticeable change is the engine behavior at very low throttle inputs, like when pulling away from a stop or changing gears. Before, the rpms would oscillate quite a bit and make things pretty jerky (sidenote: hadn't realized I was driving around this until now), but that is completely gone now. Feels sooo much more refined. No more weird stumbling when pulling away from a light.

Next up is applying the same process to the warm up map. It's painfully obvious when the car switches over from that to the warm map now. For now, I interpolated the final scaling factors (what's in the table above), as the Relative Opening and RPM axes are slightly different, and applied them to the warm up map. Will probably data log a couple drives, but I'm betting it will be pretty close.

Also, I took some notes while tuning and figured I'd share as they might be useful to others:

• Testo
  • Under "MSS54 (SERIAL)", open "STATUS_MOTOR_1" and "STATUS_MOTOR_2"
  • Log "relativer Oeffnungsquerschnitt", "RPM", "Lambdaintegrator 1" and "Lambdaintegrator 2"
  • Logging "Motor Temp." is useful for the warm up tuning
• Megalogviewer
  • Need premium version to apply settings file
  • Can replicate settings file with free version, but it's more work
  • Did not bother adding any filters to the data, just made sure to datalog when warm
• Integrator Data Interpretation
  • Initially averaged out integrators for both banks and used that, but bank 1 consistently wanted more fuel than bank 2, so ended up just using bank 1
  • Seemed to be off by a fixed offset, so decided long term trims could take care of it
  • Would have gotten there eventually with average, just would have taken longer for the same result
  • Kept iterating until I saw most integrator values oscillating around 1
• Linked XDF
  • Truncates decimals to int in both warm up and warm VE tables
  • Table stores values as decimals with 1 decimal point, but XDF makes tunerpro display them as ints and thus truncates any decimals (does not round) -> affects next iteration calculations
  • To fix, in parameter tree, right click "Density Correction_VOLUMETRIC EFFICIENCY (RF)", go to "Edit Parameter XDF Info" and change "Output Type" to "Floating Point"
    • Do the same for warm up map
• Flap map
  • I do not have a flap, so I zeroed out the entire flap map
  • Map contains additive compensation factors, so it's effectively not doing anything now
• Logging strategy
  • Mostly drove around normally, to try and capture as many data points as possible when I spend the most time
  • After a few iterations, there were some areas where engine was clearly still stumbling, so I focused on those combinations of throttle/rpm for a couple iterations
    • Found hills with no traffic to load up engine and be able to slowly climb up the rev range at a fixed throttle input
    • Think of replicating how the car would behave on a dyno

Lastly, here's my version of Pavlo's spreadsheet. Not the most readable thing in the world, but has some useful things like a (very hacky) way to autofill 1s and the warm up interpolation strategy: https://docs.google.com/spreadsheets...it?usp=sharing

[Bry5on]

Thanks a lot for this Pavlo! Just finished the warm tune and my car drives much better now. My car needed fuel in a lot of places (much like Bry5on's):



Rev matching is more responsive (have yet to get the engine to stumble like it sometimes did before) and the car feels a little livelier. Won't go as far as saying that it feels more powerful, but it does feel like it struggles less with around town driving. But by far, the most noticeable change is the engine behavior at very low throttle inputs, like when pulling away from a stop or changing gears. Before, the rpms would oscillate quite a bit and make things pretty jerky (sidenote: hadn't realized I was driving around this until now), but that is completely gone now. Feels sooo much more refined. No more weird stumbling when pulling away from a light.

Next up is applying the same process to the warm up map. It's painfully obvious when the car switches over from that to the warm map now. For now, I interpolated the final scaling factors (what's in the table above), as the Relative Opening and RPM axes are slightly different, and applied them to the warm up map. Will probably data log a couple drives, but I'm betting it will be pretty close.

Also, I took some notes while tuning and figured I'd share as they might be useful to others:

• Testo
  • Under "MSS54 (SERIAL)", open "STATUS_MOTOR_1" and "STATUS_MOTOR_2"
  • Log "relativer Oeffnungsquerschnitt", "RPM", "Lambdaintegrator 1" and "Lambdaintegrator 2"
  • Logging "Motor Temp." is useful for the warm up tuning
• Megalogviewer
  • Need premium version to apply settings file
  • Can replicate settings file with free version, but it's more work
  • Did not bother adding any filters to the data, just made sure to datalog when warm
• Integrator Data Interpretation
  • Initially averaged out integrators for both banks and used that, but bank 1 consistently wanted more fuel than bank 2, so ended up just using bank 1
  • Seemed to be off by a fixed offset, so decided long term trims could take care of it
  • Would have gotten there eventually with average, just would have taken longer for the same result
  • Kept iterating until I saw most integrator values oscillating around 1
• Linked XDF
  • Truncates decimals to int in both warm up and warm VE tables
  • Table stores values as decimals with 1 decimal point, but XDF makes tunerpro display them as ints and thus truncates any decimals (does not round) -> affects next iteration calculations
  • To fix, in parameter tree, right click "Density Correction_VOLUMETRIC EFFICIENCY (RF)", go to "Edit Parameter XDF Info" and change "Output Type" to "Floating Point"
    • Do the same for warm up map
• Flap map
  • I do not have a flap, so I zeroed out the entire flap map
  • Map contains additive compensation factors, so it's effectively not doing anything now
• Logging strategy
  • Mostly drove around normally, to try and capture as many data points as possible when I spend the most time
  • After a few iterations, there were some areas where engine was clearly still stumbling, so I focused on those combinations of throttle/rpm for a couple iterations
    • Found hills with no traffic to load up engine and be able to slowly climb up the rev range at a fixed throttle input
    • Think of replicating how the car would behave on a dyno

Lastly, here's my version of Pavlo's spreadsheet. Not the most readable thing in the world, but has some useful things like a (very hacky) way to autofill 1s and the warm up interpolation strategy: https://docs.google.com/spreadsheets...it?usp=sharing

Could not agree with this more! I also did the warmup map by building an excel re-map of the normal map using interpolations for missing data points. My warmup map is now smooth and the weird hesitations and oscillations are gone. Big difference. I don’t think it’s 100%, but certainly good enough for the first three minutes of driving as there’s no chugging anymore.

thanks again Pavlo!

[pnvhome]

A little question, how you off the adaptations? I read all the tread few times, but not understand =(

[heinzboehmer]

A little question, how you off the adaptations? I read all the tread few times, but not understand =(

Set "Lambda Adaptation_MINIMUM ENGINE TEMPERATURE (K_LAA_TMOT_MIN)" to some value above operating temp. I set mine to 210 F. The XDF linked in the video on the first post has this parameter identified.

Also, make sure to reset adaptations after flashing. Turns out that turning them off means that the DME won't update the stored value and not that the DME won't use the stored value in its VE calculations (ask me how I know...).

[pnvhome]

Set "Lambda Adaptation_MINIMUM ENGINE TEMPERATURE (K_LAA_TMOT_MIN)" to some value above operating temp. I set mine to 210 F. The XDF linked in the video on the first post has this parameter identified.

Also, make sure to reset adaptations after flashing. Turns out that turning them off means that the DME won't update the stored value and not that the DME won't use the stored value in its VE calculations (ask me how I know...).

Thanks a lot! Hope i understand all)))
Now i need to wait some warm days) Because its too cold outside, just 0-1 celsius, and engine don't warm up correctly)

[heinzboehmer]

Alright, first warm up data log done after flashing the interpolated warm up table. Waited for the car to cool down fully (more than 24 hrs) and started logging immediately after start up. Still only got like 4 minutes of logs before the engine switched over to the hot map...

Here's the interpolated warm up table compared to the first iteration using the same lambda integrator method:



(I made sure to filter out any points >= 80 C in megalogviewer)

So, it's super close to the interpolated table. Considering this table only ever really gets used for a handful of minutes, I think this is my last iteration. Very happy with all this drivability tuning

Edit: Attached the megalogviewer warm up settings profile to this post if anyone wants it. Forum doesn't like the ".settings" extension, so just remove ".txt" from the filename and use like normal.

[heinzboehmer]

Adaptations back on and they're at 1.01 and 1.00 after driving around for a bit. Nice.

[BMWfanz]

Is this method is working when cams are changed? Will it work when your setup is need to change injectors for bigger ones?

[BMWfanz]

For the record, here’s the difference between the default CSL tune and the 5 runs in version using this method on my car. Super clever, thank you for sharing!


Throttle tip in is so much smoother and the motor seems much happier. I agree that a good amount of the rasp is gone in that mid-2k RPM range. Looks like those CSL cams and the SS headers really do make a difference. With these headers, I needed fuel almost everywhere, and particularly in two islands.

My motor is a 180k mile stock internal CSL conversion, with flap, SS v1 headers and matching catted section 1. This tuning was done with flap closed to the appropriate map.

Adaptations are now turned back on, so I’ll be watching what the motor does.

edit: I’d bet that the resonances and jitteriness in the 2k RPM range can be totally tuned by changing the interpolation motor RPMs. I did this for my WOT tune and was able to get a super flat AFR curve by targeting the resonant and nodal frequencies as the interpolation points.

Just to clarify some details- If i'm not happy with my current tune- before start- i need to use stock CSL tune bin and then corretc VE table? My tuner changed ignition and WOT fuel trims- so as i see- i can go for stock WOT fuel map and just correct VE table, am i right?

[Bry5on]

Just to clarify some details- If i'm not happy with my current tune- before start- i need to use stock CSL tune bin and then corretc VE table? My tuner changed ignition and WOT fuel trims- so as i see- i can go for stock WOT fuel map and just correct VE table, am i right?

You can start from either one, although I’d suggest starting from your tune to keep the extra fuel at WOT. I started from a tune that I wasn’t happy with, then I backed off some of the timing at lower RPMs and returned some of the DME’s overall latitude to pull timing back if it detects pinging. None of the lauded tuner files I’ve seen have touched part throttle fuel, so you’re likely starting from a stock map either way.

[puma1824]

I'm trying to learn and understand but still not clicking with me. I'm not sure if I need this or what issue it's trying to solve or what issues I should be looking for in my "CSL" build to determine if I need to go down this path. Is there a dummy version of what this is fixing and what issues I may or may not have to determine if I need to "fix" it? BTW I just got my conversion back a few weeks ago so I just started driving it BUT I think I am experiencing this what one had described in a previous post "....the engine behavior at very low throttle inputs, like when pulling away from a stop or changing gears. Before, the rpms would oscillate quite a bit and make things pretty jerky (sidenote: hadn't realized I was driving around this until now), but that is completely gone now. ...."