RomRaider

Hi Everyone, I've created an MS41 MAF Tuning Spreadsheet/Application to help tune the MAF Scaling using Fuel Trim and Wideband/AFR Target (MS41.3 only) information. Simply collect several short datalogs from low to high RPM with steady throttle. Ensure WOT Enrichment is not in effect.

This program then stitches all of those datalogs together, calculates adjustments needed by analyzing short term and long term fuel trims, in addition to widebandO2 AFRs in relation to the AFR target (MS41.3 only). It then copies this intermediate dataset to the Excel spreadsheet in the appropriate columns which then performs its own calculations and outputs metrics such as, Average Correction % and Hit Count/Cell, including suggested new MAF Scalings.

Once your review of the data is complete, click 'Accept Changes' to update the spreadsheet accordingly. Choose either Tuned or Smoothened MAF. I prefer using the Smoothened MAF and let any irregularities get taken care of by tuning the Fuel Injection Base table instead. Then Paste the new table into RomRaider.

Make sure both MS41 MAF Tuner.exe and MS41 MAF Tuning.xlsm are in the same folder as the saved datalogs from RomRaider.

Step 1. Open MS41MAF Tuning Spreadsheet, edit settings as needed and close the file :
- From RomRaider, paste your current MAF Scaling in 16x16 format.
- Choose the minimum hit count per cell before changes take effect.
- Choose the change effect % from 0 to 100%.

Step 2. Run MS41 MAF Tuner which will compile all *.csv datalogs and update the MS41 MAF Tuning spreadsheet with a new MAF scaling.

Also included is the ability to smoothen the entire MAF table and have it follow a best-fit polynomial curve to ensure smooth transition between engine load/rpm, etc. Look at the included 2D chart which compares the Tuned MAF to the Smoothened MAF curve so you can decide which of the two values you want to copy/paste into the next revision of your tune.

I'm including a couple of sample datalogs so you can see how the application works together. You can have as many datalogs as you want.

Thank you mrf
I'll give that a go around christmas

Hello. I have a question. For which type of mods would this way of tuning be preferable to the other "normal" way of tuning the base fuel map according to the stft logging method? I noticed that after I put my cold air intake my fuel trims were alot more off and also load / maf values were higher than with the stock airbox. i assume this doesnt necessarily mean more power , however, due to the changed air flow the maf reading is "off". So I tried to solveit and keep the stfts in check by changing the base fuel map in every cell after hours of logging stfts and taking the average deviation and then adding/subtracting the percentage deviation. This has worked pretty well, however, seems to only treat the symptoms and not the cause. So, this maf tuning would actually treat the cause of changed airflow characteristics and base fuel map can be left alone. Dont know if im making any sense here...lol...

You are correct.

Tune MAF Scaling, if you have changed the air intake pipe, filter, or MAF sensor.

Tune Fueling Injection Base, if you have have changed fuel injectors or intake manifold.

hello. i tried your maf tuning tool that you posted in rr. downloaded everything and ran it as a test with the log files that you provided. however, when done it shows "value". see attached screenshot and file. cause?

Weird. The .xlsx file you posted is incomplete. Its missing comments in the first row of the 'calc' tab, as well as data in one of the columns. This is causing the rest of the formulas to be off. Open the vanilla *.xlsx file on your PC before running this program and see if the file has these comment fields populated. Is your version of Excel opening this file in Protected View or something and preventing my program from copy/pasting correctly? I don't know.

I did run these files again on a different PC and got it to work properly. I'm attaching the resultant .xlsx file from it.

Thankx for reply.. Maybe because I ran it on my notebook where I don't have ms office installed and opened the file in the online OneDrive excel application. Gonna try it again tomorrow on my other notebook wwith ms office installed.

Thanks @mrf582 for all your posts and this little tool! I've been learning a lot from you and the other members on this forum over the last few weeks.
This will come in very handy when we change our OBD1 engine over to OBD2.
I can confirm that the sample files work on a WIN10 laptop with MS Office 2016. But it doesn't like long path names or other drives than C.
I'll try some logs over the holidays - do I absolutely need the AFR target and MS41.3 or should I be able to use a stock O2 sensor and MS41.2 as well?

If the log doesn't have target AFR or WBO2 data, then only Fuel Trims will be used to calculate. So yes, this will work for any MS41.

Odd. I don't know why my last post was posted three times. I got errors the first two times - looks like this forum doesn't have the function of addressing someone with the @ sign and gives you an error.
However, @mrf582 - I noticed that your original sheet "MS41 MAF Tuning v1.4.xlsx" is protected, so I wasn't able to follow your instructions to copy and paste my current MAF table into the "current" field. Yet, after executing "MS41 MAF Tuner 221209.exe", the sheet was unprotected and I was able to paste my current MAF table.
So, if you don't mind, please unprotect the sheet or change your instructions to paste the current MAF after importing all the logs with the .exe.
Cheers,
Michael

Those cells for Current MAF are unlocked. You should've been able to edit them even with the sheet locked.

Anyway, I'll post up another version later. I also added a couple of macros to accept tuning changes and automatically copy/paste/clear etc.

I finally got around to taking some logs with my neighbors Z3. The MAF tuning sheet seems to work well. I definitely need more controlled logs to actually tune the MAF but it looks like this will come in very handy when scaling a new Bremi Porsche 3.5" sensor for the race car.
Thank you very much mrf582! Well done!
Attached are initial logs and results of a Z3 with a S52 stock engine.

I noticed in the excel file the MAF tables are on a 15x16 format when my current MAF on romraider uses a 16x16 table so when i paste my current MAF table it overlaps one row?

The Excel file is fine at 16x16. Please count the rows/columns manually if you don't believe me.

Your problem occurs when Pasting into RR. First click on the top-left most cell and then go to Edit -> Paste.

Hi firstly thank for your little but big tool.
I dont have factory o2 sensors on my car and disabled from ecu. But i have AEM 30-0300 wbo2 kit with serial output cable. I can log engine operation and my afr. With this log will your tool work?

Note: its e36 328i manual ms41.0 with afe power intake kit, m50 mani, ebay headers, m54 intake cam as intake, m50nv intake cam as exhaust and m50tu pistons.