LS1Silverado05

iTrader: (41)

More of a curious question than anything.

Is it common place to tune the MAF of a dead stock car? Are the minor dial ins worth it?

I was familiarizing myself with the software on my 09 G8 and I found that when I logged MAF HZ vs STFTs I was seeing a +- 4 or so over a wide range . I did a lengthy log and multiplied % half and saw them come in around +- 2 and in many ares +- 1 or less.

Would that be normal or should my factory tune have been closer than that? (Stock car, Stock Airbox and Clean Paper Filter)

jimmyblue

iTrader: (11)

I've been told by an outfit that tested some, that
the MAF is a 5% accurate piece. This from a group
of factory-fresh ones.

MAF tables vary to similar extent, trying to account
for motor-config differences I suppose (the piece
is the same, the tables vary).

The big question is, what drives your error rollup.
The MAF, if clean and screened in a straight tract,
probably is not it. Especially below 4KRPM there is
a lot of non-MAF contribution to the Dynamic Air
Flow & Mass numbers (if you see Dynamic Airflow
differing from MAF Airflow, this is in play - and do
you want to bend a factory-cal'd instrument to try
and match the speed density airflow, which is much
more of a contraption built on numerous variables?
You want them to agree, but who really ought to
change?).

You could have more error from fuel pressure (which
nobody, hardly, logs or has the ability to) than the
MAF, depending on your maintenance preferences.

2xLS1

iTrader: (25)

It's a mass produced electronic/mechanical product with a lot of variables and production tolerances. That is why they give it the ability to correct itself.

LS1Silverado05

iTrader: (41)

Well yeah, common sense tells me that, Im just saying we strive to dial in our cars. In this case is it a wasted effort because if its +- 5 you are probably chasing fuel variables etc?

You always see people say to try and get it as low as possible, but in reality it seems like youre really only getting it close to zero in that exact enviroment of weather, fuel etc.

More less, should a person bother even working that on a stock car?

LS1Silverado05

iTrader: (41)

I apreciate the input...

2xLS1

iTrader: (25)

Didn't appear that way. I answered your specific question if it should be considered normal.

LS1Silverado05

iTrader: (41)

Do you or do you not bother tuning the MAF generally on a stock vehicle probably should have been my more direct question.

Thanks for your input.

jimmyblue

iTrader: (11)

I do not. But I have picked between various factory
tables and stuck with the one that gave the best
results (fuel trims & wideband).

The question is, what instrument do you have that
is better than the stock MAF accuracy, that you
would choose to believe instead? And meanwhile
neglect the other unknowns?

Another thing to consider is that the airflow number,
MAF or otherwise, affects more than fueling and
spark. It also pulls line pressure from the trans if you
lie about airflow toward the lean (low air mass) side.
This is how people with low mods eat transmissions.
Especially if your big plan includes porting the MAF
or using an oiled air filter. Or just shaving the table
chasing "lean is mean".

If you do not know for sure that you happen to have
a MAF which is wrong, there are better ways to get
the fueling you want. All you want of the MAF, is
accuracy. You can't judge accuracy by what's coming
out the tailpipe, that's a electro-computo-chemical
clusterfuck. You want the tailpipe result right, sure.
But you can't pin any particular piece of it to the MAF.
So it's not real rewarding to try.

LS1Silverado05

iTrader: (41)

This makes good sense actually. Its sort of how I felt when messing with it. I asked myself, "Ok I may have achieved +- 1 compared to the stock table, BUT what else have I effected?" Thanks for the explanation from your point of view.