S54 airbox +288/280 schrick on CSL software tune

[Bry5on]

You can use the fuel trim values to tell you what to change and where. Lambda integrator scales into the VE, you can multiply VE by this value and it won't overshoot because of how the math works out. I semi automated it with Excel and Matlab and takes about 4-5 good drives until the entire table is done. My entire usable RPM range is near perfect, regardless of the conditions.

Maybe I’ve been getting this wrong the whole time, but I thought fuel trim was just a single number for short term and a single number for long term. How are you applying this to your whole map?

Also, I think I used the wrong term above when I said trim. What I meant was disabling closed loop control. It sounds like your method above actually works *with* closed loop control. Any chance you can point me to the table you’re using to adjust trims? I must have just overlooked it somehow.

thanks!

[Pavlo]

I’ve been interested in tuning my part throttle CSL maps as well. How are you disabling fuel trimming to stoichiometric while driving, and what AFR are you targeting when it’s disabled? Between 2-3k there seem to be a bunch of resonance modes that cause AFR to swing wildly. I’ve tuned it out of WOT by changing target trims and RPM in my WOT map but haven’t figured out how to start with the part throttle map.

You can use the fuel trim values to tell you what to change and where. Lambda integrator scales into the VE, you can multiply VE by this value and it won't overshoot because of how the math works out. I semi automated it with Excel and Matlab and takes about 4-5 good drives until the entire table is done. My entire usable RPM range is near perfect, regardless of the conditions.

[BMWfanz]

Yeah it’s a bit of a process every time. I’m only logging a few parameters as you get data faster with fewer selected, but it’s still an effort. I’m grateful to have the tool though, most of all.

Currently fighting with my notebook- on old one was windows 7 and my AEM wideband O2 worked properly- now on new laptop on windows 10 can't add external device (

[Bry5on]

You using mss52/mss54/mss54hp ecu in Testo? Quiet annoying to select parameters there

Yeah it’s a bit of a process every time. I’m only logging a few parameters as you get data faster with fewer selected, but it’s still an effort. I’m grateful to have the tool though, most of all.

[BMWfanz]

Yessir, Testo

You using mss52/mss54/mss54hp ecu in Testo? Quiet annoying to select parameters there

[Bry5on]

Which logger are you using? Testo?

Yessir, Testo

[BMWfanz]

I use a wideband to log my drives. Once you tip in the throttle pedal, the DME will use the calculated value (+trims) to control fuel injection, but after a few seconds? It starts going closed loop with the O2 sensor.

If you check some of my logs, where pedal position is constant, you can see the drift here: https://datazap.me/u/bry5on/brysontu...g=0&data=4-5-6

Which logger are you using? Testo?

[BMWfanz]

Looks like my issue- but as I've sorted out it's all because of wrong map that I've changed- so no injection timing were increased so basically my car now is lean on partial load. Will try to fix it on weekends

[Bry5on]

I'm only started my tune- but i don't see something special on one position throttle and 14.7 AFR- on load it should be like in maps, or your car hestitating on one position pedal on 14.7 afr?

I use a wideband to log my drives. Once you tip in the throttle pedal, the DME will use the calculated value (+trims) to control fuel injection, but after a few seconds? It starts going closed loop with the O2 sensor.

If you check some of my logs, where pedal position is constant, you can see the drift here: https://datazap.me/u/bry5on/brysontu...g=0&data=4-5-6

[BMWfanz]

Right, so how are you tuning the part throttle map if the O2s are targeting 14.7 regardless of your map?

I'm only started my tune- but i don't see something special on one position throttle and 14.7 AFR- on load it should be like in maps, or your car hestitating on one position pedal on 14.7 afr?

[Bry5on]

O2s corrections on flat throttle are always targeting 14.7 AFR, if you dont need it i think you can decrease maximum voltage of 02s or disable it if you think that your afr is good.

Right, so how are you tuning the part throttle map if the O2s are targeting 14.7 regardless of your map?

[BMWfanz]

Thanks, I’m curious how you’re doing this tuning. At part throttle, the ECU appears to be programmed to return to 14.7:1 AFR from O2 sensor feedback. How are you disabling this to be able to tune partial loads? Both my maps from popular tuners directly use the CSL part throttle fueling, and after seeing what I needed to do to WOT to move the peaks and valleys around, I’d like to apply the same fix to the part throttle map. These resonances that cause lean/rich are easy to tune at WOT while it’s in open loop, but I haven’t found a way to force open loop in partial throttle.

O2s corrections on flat throttle are always targeting 14.7 AFR, if you dont need it i think you can decrease maximum voltage of 02s or disable it if you think that your afr is good.

[Bry5on]

Fuel for partial loads I think is in KF_RF_N_AQ_REL

Thanks, I’m curious how you’re doing this tuning. At part throttle, the ECU appears to be programmed to return to 14.7:1 AFR from O2 sensor feedback. How are you disabling this to be able to tune partial loads? Both my maps from popular tuners directly use the CSL part throttle fueling, and after seeing what I needed to do to WOT to move the peaks and valleys around, I’d like to apply the same fix to the part throttle map. These resonances that cause lean/rich are easy to tune at WOT while it’s in open loop, but I haven’t found a way to force open loop in partial throttle.

[BMWfanz]

I’ve been interested in tuning my part throttle CSL maps as well. How are you disabling fuel trimming to stoichiometric while driving, and what AFR are you targeting when it’s disabled? Between 2-3k there seem to be a bunch of resonance modes that cause AFR to swing wildly. I’ve tuned it out of WOT by changing target trims and RPM in my WOT map but haven’t figured out how to start with the part throttle map.

Fuel for partial loads I think is in KF_RF_N_AQ_REL

[BMWfanz]

You are changing in the wrong map. 0401 is VE controlled which is different map. Also called often the famous 3 „alphaN“ maps. Sometimes the public xdf‘s are incomplete or wrong scaling, but a great base for your own xdf.

Ok, will try alpha n map and post the results