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

[Obioban]

Hello all,

Disclaimer: I'm not selling anything or competing with sponsors-- the below is 100% free/informational. Flashing can be done with BMWflash (free) using a generic USB/OBD2 cable (ebay/amazon).

Cross posting this from NAM3forum.com, because it seems like many of you may find it useful, as well. 5 pages of discussion there, and the creator of this is fielding questions.

The basic premise is you install a wideband, record going for a drive, and the car generates a new tune-- focusing on optimizing part throttle/low RPM. Flash on, repeat until perfect. This 100% fixes the throttle response/driveability issues that the CSL engine management sometimes suffers from, especially if you're running non stock cams,headers, injectors, plug temps, etc.

This does NOT increase peak power (from a good tune), as that's what gets optimized with dyno tuning. This is for various levels of partial throttle, particularly at low RPM (at least that's where my car used to suffer).

https://nam3forum.com/forums/forum/special-interests/coding-tuning/242281-a-quick-and-easy-way-to-street-tune-your-csl-conversion-for-drivability#post261777

I've told someone on this forum before that I'll show how I merge Lambda Integrator/AFR data logs with the VE table to semi-automate tuning. I finally got to doing this.

I usually use MATLAB, but it is a bit of a niche software so I made spreadsheet and a video for you all. Link for the spreadsheet and the configuration file for MegalogViewer are in the video description.

The main idea is to use average Lambda Integrator values and multiply them into the VE table. It never overshoots just because of how integrator is calculated and took me about 5 good drives to go from trash to a pretty nice tune. You will need a wideband for the wide open bits when you go into open loop, but thats honestly the easiest part of tuning. I got tired of people claiming that a few wide open pulls on a dyno is a tune, but I do realize its also unrealistic to expect OE level refinement from a person and his laptop while you pay him $500.
Be careful to not data log when your engine is cold (you have a separate table for cold). I disabled long term fuel trims as speed density doesn't really care about air leaks in the system, but still periodically check to make sure everything is happy.

Hope it makes sense, if it doesn't I'll do my best to explain better. I may try and do a macro in the future to really automate it, but if you got this far with your CSL tune, you got it.

https://youtu.be/V6nvetZfuy8?si=EDLbYT2QZTPkxS5F

https://docs.google.com/file/d/1NiMCiA2VQ_EYIS6i_QZ13gksjLwfPK-O/edit?usp=docslist_api&filetype=msexcel

https://drive.google.com/file/d/1isO7rw4WOJe5gc5ykPRTjmLipNVMbHyR/view?usp=drivesdk

:beer:

[0-60motorsports]

Obi, Thanks for posting this here. Great info.