RomRaider

I built this spreadsheet to help me scale my MAF sensor. It evolved into more of an Excel based utility.

Copy in your current MAF scaling and your logged fuel trim parameters. It will filter our unusable data such as open loop points and will prompt the user to select dv/dt and temperature maximums to dial out noise. This allows you to tune the MAF sensor much more quickly than by hand and with much more accuracy than utilities that to not dial out excess noise.

This is based on the Closed Loop tuning method posted by Williaty.

This is my first posting of this worksheet so please try it out and let me know of any revisions that need tobe made.

DISCLAIMER: Use at you own risk.

Can you provide a link to the post of Williaty discussing his methodology? Thanks

A shortened version of what the spreadsheet does, per Williaty's method is:
- First, it deletes any non-closed loop data.
- Next, it pulls all the A/F corrections, both learned and instant out of the log data. It compares those against the time stamp. It prompts the user to delete any A/F corrections that are wildly fast. This is generally caused by throttle blips.
- Next, it graphs the Intake Air Temperature points and promtps the user to define a maximum temperature. This allows you to remove any bad data points that were subject to heatsoak.
- Next, it plots out the raw values, mean, mode, proposed changes, and user defined changes. This gives the user a visual guide to see what corrections were being made.
- The utility's proposed changes default to the more conservative value of either the mean or mode for the sake of safety.
- The user can change the values in the green columns to the right. This is important to smooth the curve because when there are very few data points available (example - that point between idle and cruising around) the corrections can be subject to error caused by the lack of good data.

I just posted a slightly revised version of the utility (Version 1.6a). It has a separet sheet for MAF scaling values and has a click-button method to edit the suggested new MAF values.

It should be a little more user friendly and is a smaller file size.

Looks good!

I have just gotten through the break-in period for my new engine and wanted to start tuning today, so I will give it a shot.

Thanks for posting it

Had an issue publishing new MAF scaling.

In module 2, Sub NewVal() there is a var called lastrow which needs to be initialised to 62.

Here is the ss with the data:

To get the error you have to remove the line that I suggested above.

I was running this with Excel 2010.

The IATs are in Celsius in case your wondering.

Apart from that, the data filtering appears to be pretty good, judging by the MAF correction scatter plot.

Thanks for checking it out. I'm running Excel 2003 and even if I remove the line, I can't get it to produce that error. Is it just a runtime error?

Also, I log temperature in Fahrenheit... it didn't occur to me that international logs would be different, lol. I'll make it non-unit specific.

Im using OP2 can for logging. For a 15 minute log and the parameters needed for this, I can get almost 40,000 lines at 50 samples per second. So can I assume that the data I collect need not be corrected via user input? Also since I can only fit one 15 min log at a time (I had 2), I filtered the first one then after pasted the second.

I typically feel safe with about 30,000 lines of logging if i take care to drive in all possible load ranges while still in closed loop. That gives you a very good picture of what your car is doing.

The utility should work for up to ~60,000 lines. The graphs in excel can only read something like 30,000 lines though so you'll only get to see part of the data when you're choosing your dv/dt and temperature limits though.

Thanks to your spreadsheet, I got to dial in quite easily close loop range of my maf. There's still manual adjustments that need to be done though.

I'm about to give this a go instead of using the romraider tool, I've already made one iteration using RR and have updated my MAF scaling table to suit - should I use these values as "Original Values" or the stock values for my rom? I'm guessing the former but wanted to be sure.

You're right. You should use the values that your car is currently running as the "Original Values"; in your case, the RR modified values.

Thanks for this. I've been using this method manually for a couple years now. This spreadsheet should save quite a bit of time.

Awesome, thanks very much.

Got a bunch of highway logging done on the way back from the track on Monday so lots of good data.

So judging by the posts above, it doesn't matter that I'm logging IAT in Celsius now? (graph is in F), or should I convert my logs to Fahrenheit before I enter them in to the spreadsheet