MAFT Calibration via DSMLINK - How To's

[confusionisbad]

Here are 2 links: (assuming you have DSMLINK and 1 of the following)

MAFT Calibration By WBO2:
http://dsmlinkwiki.redacresracing.com/default.aspx/DSMLink/MAFTCalibrationByWBO2.html

MAFT Calibration By Logged Boost (AEM or GM map sensor):
http://dsmlinkwiki.redacresracing.com/default.aspx/DSMLink/MAFTCalibrationByLoggedBoost.html

Eddy

[JSMCPN]

Here's a log of my 338 HP dyno pull. The WOT MAFT calibration was just about right. Compare BoostEst to GM3BAR. You see it's perfect at 1800 and 2300 RAW Hz. Between those points, the ECU sees a little more airflow than actual. So, I move the 1600, 2000 and 2400 Hz sliders negative until that little hump flattens out. You also see that between 330 and 1200 hz, the ECU sees a bit less airflow than actual. I need to move 400, 800 and 1200 sliders positive to raise the curve to match the GM 3BAR.

Cruise and Idle tuning use the same basic method, but I've found that at low airflow, it's tough to get BoostEst and 3BAR to match - more importantly for these Hz ranges, you want your fuel trims to be really close to 0%. Drive on the highway with a friend, have him call out MAF RAW values and current STFT & LTFT readings. As the driver, you must keep the MAF signal as steady as possible so the ECU can adjust fuel trims.
Drive the car at 150, 250, and 400 Hz for as long as it takes the ECU to trim fuel for that Hz point. Your passenger will adjust airflow sliders to yield 0% fuel trims. Be patient, fuel trims are slow to balance out.

[dsm_gsx97]

... it's tough to get BoostEst and 3BAR to match - more importantly for these Hz ranges, you want your fuel trims to be really close to 0%.

I'd imagine this is because the GM3bar isn't very consistant (as RRE describes it). It does a good job to give you an indication of the boost your running (or close too within a psi or two), but I'd think the AEM or Kavlico map sensor would make this an easier job wouldn't it? Of course both those map sensors are double the price of the GM one though. So I guess it's how good you want to make it.

It's awsome you took the time to do this stuff. I guess in this aspect I was lazy because I never did this the whole time I was using DSMLink. Very good idea to do though...