blackbird345

My brother's Skyline uses a MAF and a MAP, whats the difficulty with us doing the same?

foff667

iTrader: (2)

you can but the maf maxes out at 7-10psi of boost usually meaning your not getting completely accurate fueling after that...you just use the pe table to fudge the numbers the best you can.

blackbird345

So can i change the stock MAP to a 2 bar and still use the MAF?

RedHardSupra

iTrader: (1)

yes, but all you'll find out is how quickly you can max out MAF

GuitsBoy

iTrader: (4)

So why is there no OS update to get past the 512g maf limit? I would think if they can release 2 and 3 bar updates, and add other tables, increasing the 512 wouldnt be out of the question...

RedHardSupra

iTrader: (1)

heh, i was just thinking the same...

slow

iTrader: (7)

OR why hasn't anybody made a maf that supports a large airflow?

I tune cars with way more air than that through a maf, without issues, just not for GM.

Ryan

GuitsBoy

iTrader: (4)

Thats what I thought at first, but its actually a computer limitation that wont recognize more than 512g/s airflow.

slow

iTrader: (7)

Trust me that can be worked around.

2003-4 cobras has a 63.9# limitation as well... that doesn't mean tuning them with a maf that supports 120#+ of airflow can't be done.

Ryan

eb02z06

iTrader: (18)

How come no one has come out with MAF for GM like the Ford cobra's?

blackbird345

Exactly there must be something that can be done. Someone mentioned a larger truck MAF would that work?

dynocar

We also do alot of Fords and there we just simply move up to larger MAFs, such as the Ford lightning, SCT BA2400, BA2800 etc which steps us into the 1000 HP arena. The SCT software we use allows us to enter what MAF we are using then it automatically rescales other tables such as MAF table, engine and injector size etc to make it work. Before things went full circle again and now again many advocate SD, when set up properly there is no substitute for a MAF system, much more accurate at adapting to changing environment or engine conditions. But setting one up properly is a challenge because of the space needed to keep the airflow strait and non turbulent into the MAF for proper readings, especially on boost blow thru MAF systems.

ringram

Well perhaps yes you can rescale all other tables 50% and double the maf to 100%. But there is a hell of a lot of tables and tables relationships etc.
You are right though, there is no reason why its not possible. Just requires some time.
BUT, if you can get the same or better results with MAP only, why bother?

eb02z06

iTrader: (18)

Why can't we move the MAF on the inlet of the blower like on a mustang?

slow

iTrader: (7)

map just tell of restriction, maf reads airflow.

What does the pcm use to determine fueling... airflow.

Enough reason for me to like a maf.

Ryan

cantdrv65

iTrader: (3)

Correct but the pressure drop caused by that restriction and read by the MAP sensor is directly related to airflow....Too methods that achieve the same results. I like the MAF sensor myself as well, but it isnt accurate without adjustment as well.

ringram

With a wideband to adjust for MAP inconsistencies, usually related to the VE table. Its possible to dial in an accurate table which tracks to within +-1% at various IAT temps as well as right into 2 or 3bar pressure.
As discussed the MAF max's out at around 511g/sec.
While these limitations exist the best solution for FI applications is a 2 or 3 bar map sensor and an accurate VE table with SD tuning.
Im not aware of any other solutions that provide better results than that.
You wont gain anything from the MAF IMHO other than more flexibility for NA apps.
Surely you go with the best available for the application you require, which as far as I can see is MAP based SD tune at present.

slow

iTrader: (7)

They may be directly related, but how do you get that actual airflow value?

Ryan

soundengineer

iTrader: (16)

by using AFR vs commanded afr using AFR Error % just like you did on the VE tables