I have a descreened MAF actually GMS ends. I have a custom air intake system that the filter, MAF, and IAT sensor are all under the nose of the car in a cold air setup. Are there any things i should be changing with Tuner to make that work better / work right. I have a tune on the PCM now but trying to get it better as i never felt it was quite right. So take it easy on me cause i am pretty green to the PCM tweaking. Thanks

 

when i did mine i scaled the MAF tables by 1.09 and then fine tuned from there using VE tables ... OBD1 LT1 A4

 

I would think that you only really need to tune the MAF table if the car is running lean (PCM adding fuel) during cruise or WOT.

What I've been doing is to log the car, and work through the log as follows: I sort the log by MAF reading, then like from 6-7 g/s I average the LTrims for both banks together. I do this for each step in the MAF reading (6-7, 7-8, 8-9, etc...). I then load up my editor and for each point in the MAF table, I make the corresponding adjutment. So at 8 g/s in the MAF table, if my log showed that the car was -2% at that point, multiply that point in the table by 98% and go to the next one.

I found that after the first round like this, the car was really close. I'm waiting to load my 2nd round run now. The adjustments will get smaller each time you do it, because the car will be closer to 128 each step.

All this really does though is to change the base fueling for a point in the MAF table, getting the PCM either closer or farther away from 128 BLMs. Where it really makes a difference is at WOT, because if you can get the BLMs just a tad on the rich side, say 124-ish, then when you go into PE mode you're only dealing with the PE mode fueling tables. Should make it easier to tune PE mode.

 

I did a LOT of testing with mine. First I found better performance WITH the
sceen in, the screen helps the sensor get a good read. And with fully ported
ends and a screen I found I needed to adjust the maf table by 1.13

 

Now the stupid question. I have 4 MAF tables, looking with Tuner, do i need to edit all 4? The more i find out the worse the tune i paid for looks oh well live and learn.

 

To edit the whole range your MAF senses, you would have to edit all tables. Notice the grams/sec. You can use scan logs to show you what your fuel delivery is at and what gm/sec your MAF sees at the time. That will let you edit specific cells if you need/want to.