RomRaider

so is it best to sort out the latency first and sort out the maf second?

ps my air filter sits in place of my fog light so im not to sure if that is what caused my iam to drop when it was raining

Add some latency like you did before and then modify the MAF scale. The IAM dropping had to do with knock. Who knows what caused it. It could have been a lean condition, etc.

thanks for your info gabedude.

could it be then that water got into the maf and caused it to go lean?
obviously i was not recording data at the time it happened but was watching the min/max stored values on the logger screen and there was no knock.

is it best to use rr logger to rescale the maf as at the moment the way my fueling is it seems to be all over the place.
anyway once again thanks for the valid info.

The RR logger will only scale the lower portion of the MAF (fuel trims). To do the upper portion you have to get some plots with your WBO2 and estimate. Modify G/S value or voltage (people do either, but Subaru modifies G/S). If you are too lean at a certain airflow, tell the ECU it has more airflow at that voltage, increase G/S or decrease voltage. The opposite is true if you are too rich (lower G/S or up voltage).

Water on your MAF wire can cause it to go lean and knock.

thanks again for the info mate would of been realy stuck without it.i didnt realise that the maf scaler only rescaled the lower part of the maf table i guess that explains why after about 2v it read zeros then 300 at 4.69v.

isnt there a sticky somewhere that tells new members about the maf and injector scaling tab so that you dont have to keep repeating your self to newbies if not it would be nice if there was.

There is a search function.

lol everytime i use that i get side tracked into reading something else

gabedude - Does this new theory you are suggesting still go out the window with modded stock injectors (decapped)? From what i've understand, it seems a lot of the guys i've been reading and learning from (ride, mickey, yourself, joninCT) agreed that latency adjustments were needed for those.

From my own experience, I have modded injectors that tested at 897-900cc. When I first was tuned on them, the tuner left the latencies stock and set scalar at 897. The car ran horribly. He felt that the provided scalar number was incorrect, so he changed the scalar to about 750cc, and adjusted the maf instead. Car ran, but idled like crap and a few days after the tune, eventually learned a +5% correction in "D" learning. Not satisified with this and after reading 100s of posts here, I set the maf back to stock (have stock intake), adjusted latencies close to what Ride5000 came up with and settled on a scalar of 820cc. The car runs much better now, but i have a fluctation of "D" learning of about -1 to -1.5% and a hesitiation i can't seem to get rid of no matter what I adjust tip-in to.

Even with them decapped, running stock FP, the real world latency (latency is the time it takes the injector to open) will remain the same. What your tuner should have done is modify the MAF scaling. This is what Subaru does. Jon upped his fuel pressure. That causes the real world latency to actually increase. That is why it worked for him.

I did all this with the MAF scaling only. Now I just need to fix my exhaust leak so my stft are better at idle and it stops "shooting fire" (as my mother in law puts it) out of the DP to catback connection.



I have a little work to do on the TD area, but thats about it. Running 17.5 peak PSI so far and 15 at redline. Peak EL there is 3.0. 740CC scaler, light blue top feed WRX injector (same as STI pinks, they are DW750's) stock latency.

Do you have a graph of your MAF table?

What I did was make an AFR deviation list and applied it to G/S. It took 4 runs to get it nailed up to 300 G/S. Once I up the boost near redline, I may have to get it closer to stock in the upper end. I am going to run super rich though just in case it goes lean. I also watch the road and my WB gauge only and if the AFRs go above 11.5 past 5k rpm, I let off.

Also, I may end up bumping the scaler and applying the same offset to the new MAF scale so I can hit higher G/S numbers. It doesn't really matter though what G/S reports, volts are volts... I'm prolly gonna need a big MAF when I up the boost. :/

The injector tab in the logger suggests that I use 810cc, with no correction in latency, but when I do my LTFT are all massively positive. I'm guessing I should go back and scale my MAF again after setting the scalar to 810, is that correct, or should I leave it be? Currently my trims are all within 2 or 3% of zero, worst.

If you are using stock FP, then you can use the MAF tool to get fuel trims inline.