Mark_ZZ3

My first tune was my son's TPI. Ran aweful rich at first. Adjusted MAF tables and it runs. For a 305, it sees 211 grams of air at 4800RPM.

My truck, is a 350. It sees 174 grams of air at 5000 RPM.

Seems odd. I tried a second MAF in my truck and it's about the same.

I'll swap MAF in my son's engine and see what happens. But thinking his MAF might be out ... explains a lot about the tuning challenges. Was rich rich rich. Had to set inj constant way up to get BLM in range.


My question

- how much variance is there in stock MAF or with aftermarket MAF
- Does having a cone filter on the end of a MAF create odd air flow resulting in incorrect readings?


... one good thing about running into issues/challenges ... it make you learn a whole bunch.

Mark.

tuningnewb

I don't have first hand knowledge of tuning a MAF system, but I've long read on many forums, 'Don't remove the screen' from MAF's the come from the factory with a screen as doing so will mess with their accuracy and the same people also indicate not to use aftermarket MAF's like Granettli either.

I did descreen the MAF on my old 1996 Impala SS and could see in the data log that it did flow more according to the data log, but if that gave me more power, is a different question.

I would think MAF's of the same model are very close from one to the next, since the same tune is applied to all engines. They don't build a tune to match a given MAF. All of the components must meet some minimum tolerances.