My USDM WRX STI LIMITED 07 - Log

[zefex]

Hi this is my log available for download. I am trying to understand all of the data but am having troubles finding a good source of information on the data itself. If someone wanted to look at the log and tell me what they think that would be wonderful. My Knock seems to be fine mostly zeros. Im pretty sure my MAF voltage needs some correction. Any suggestions? Thanks!!!

I dont have my wideband Bosch sensor yet and i dont have my air/fuel display or a external knock sensor, but i want to correct my airflow using what i have built in. I have a SPT S.R.I. . Want to make it functional.

Im guessing from my airflow correction that i may need to lower the MAF voltage? So im going to put my airflow correction table into my excel and find the medium. Then im going to take that number and subtract it from my MAF voltage? I dont think i have the formula right. I wish there was a formula FAQ

Thanks for your helps guys!

[Jon [in CT]]

It'd be nice to know what, exactly, you're logging. Make/market/model/year/trim would be helpful.

[zefex]

Thanks for your reply! It is a:

Subaru USDM WRX STI LIMITED EDITION 2007 with factory remap.

[mickeyd2005]

You can scale your MAF table in the 5 to 60 g/s range using AFR learning and some careful driving or you can use some statistical analysis which is what I did.

Above 60 g/s, you'll need a wideband.

[zefex]

thanks for your reply mickeyd, what do you mean by carefull driving? can the ecu learn this on its own? thanks again.

[mickeyd2005]

What I meant by careful driving is that you have to "set" your afr learning by driving in each maf range.

The hardest range to set is the highest range especially if you have reduced your OL/CL delays. I found it easiest to drive fast on an uphill portion of the freeway but keep the throttle constant so that you don't drop into OL.

You have to set your low MAF range first and then scale your OL range. Otherwise, AFR learning will screw up your OL range.

This is what I would do...

1. fill up gas tank.
2. drive at a variety of maf ranges until afr learning is set. This means slow speed, medium speed, high speed... all with throttle as constant as possible. Log everything.
3. read afr learning for each maf range and adjust your maf table accordingly. Remember this only works up to approximately 60 g/s. I would use the highest afr learning to adjust your maf table above 60 g/s
4. reflash with stock rom except the only change is the maf table. Use stock fueling tables.
5. set your highest afr learning value by driving uphill on the freeway at high speed.
6. use wideband O2 to scale rest of table. However, go slowly. Datalog up to 4000 rpm at WOT and if you are too lean. STOP. Then datalog again up to 5000 rpm at WOT etc... until you have all the data you need.
7. reflash.

I would try to do this all on one tank of gas because you want the entire maf table to be a "matched" set. That way, later on if the fuel changes, then afr learning can properly account for it.

[mickeyd2005]

I have a statistical based excel spreadsheet posted on enginuity.org to do a more accurate job of steps 2 and 3. However, it requires a lot more logging.

I think most people just use afr learning.