TimZ28

Mod edit: please take this to PMs if you want to discuss conduct with him, thanks!

Jpr5690

iTrader: (13)

LOUD NOISES!!!

Jpr5690

iTrader: (13)

but really did the whole tranny line pressure thing ever get resolved.. i"ve been reluctant to de-screen my 85mm maf because i remember reading about it affecting the line pressure (but this was yrs ago so.. )

SmokingWS6

iTrader: (1)

I have been running a descreened maf for years. Never had a problem once I recalibrated the maf table.

If your running a strong H/C setup you will see increased manifold vaccum at wot with a stock maf vs a descreened/ported maf.

soundengineer

iTrader: (16)

the whole key is tuning...

I have tuned many cars with descreened/ported MAF's
as long as you tune the MAF table using A/F error % it comes out fine..with no tranny issues...

if you dont tune it it will report a different value than what it really is and you get hard shifts or sometimes sissy shifts...

The SD enhancements now in HP Tuners offer tables to fix this tranny issue that also happens when the MAF is removed or fails or is set to fail at 0

Viper

iTrader: (6)

"If your running a strong H/C setup you will see increased manifold vaccum at wot with a stock maf vs a descreened/ported maf."

Excuse the ignorance but is this good or bad? Serious question.

soundengineer

iTrader: (16)

doesnt matter what it does..as long as the values in teh table are tuned correctly its all good....

Jpr5690

iTrader: (13)

ok so how do i retune after removing the screen?

as of now my wot a\f is good but my part throddle trims rich so im guessing after the descreening ill need to adjust my pe multipier ....?

soundengineer

iTrader: (16)

no...
you set PE to desired WOT A/F

then you use AFR error (basically 100*(AFR-Commanded AFR)/commanded AFR
you can then change your AF by this amount..
log MAF HZ and plot this AFR error vs the MAF HZ and you get an amount to change the MAF by...
you do this also whe you are tuning the VE...only VE is MAP and RPM based..MAF is all just by MAF Hz

fotoboy

iTrader: (1)

Why is a 2004 zo6 maf descreened from the factory if it doesnt add hp?

OUTLAWZ RACING

iTrader: (9)

Funny my 02 z 6sp did 345 360 with a lid and choke master, At LG did a dyno day at DC same mods put down 347 358. It was a little warmer that day around 90* V 86*from LG. Mind you the afr was 13.3.1 descreen maf While the car was on the dyno made 353 365 AFR was a solid 13.3.1 all the way up to 6k the went to 13.1.1 from some reason car had 6k miles on it I bought it new in 02

onfire

iTrader: (17)

Will that method bring the MAF flow rate closer to the "calculated flow rate....DYNAIR" ???? Also, you would have to zero the ltrims and cut off the strims.....

Jpr5690

iTrader: (13)

so if i just mulipulied the maf values by 110% wouldent this get me prety close?

SmokingWS6

iTrader: (1)

Starving the motor for air basically. Which is why the days of having to use a stock maf have past.

txhorns281

iTrader: (12)

That would all depend on how well your VE table is calculated, but during MAF operation, the MAF controls the base airflow determination. This is why we tune the VE first (and b/c the tools we have allow us to tune it easier), then tailor the MAF airflow model from the VE airflow model.

Assuming the engine is at the very least not running a lean condition (anywhere), we don't consider L /S trims in WOT fueling so for PE tuning this is not a problem

jimmyblue

iTrader: (11)

If you already have the truck table in there then you may be
as close as you need to be. All that you want is for the big
end, WOT delivered AFT to equal commanded. Log these and
the MAF frequency and it's a pretty easy thing to hand-true-
it-up in Excel just by eye. Fancier methods out there of course.
Thing is you have the new big injectors that got only a first-
order table replacement w/ no fuel pressure profile element to
it, you have the big lumpy cam, there are a few things there
that can push on AFR besides the MAF itself.

I can't remember your MAF details now. Was this a SLP, SLP
w/ resistor removed, or ???

Jpr5690

iTrader: (13)

SLP WITH NO RESISTOR AND NOW NO SCREEN.. as of now im still using your maf tables but a mailorder tune form tsp with their estimates on the IFR table....

Ubergeist

iTrader: (6)

I don't know I was always tempted to de-screen 'em, but thought it wasn't worth the hassle.

Full-Force

iTrader: (11)

In my oipinion the screen is a filter to keep debris from damaging the micro fiber size sensors in the maf. The divider that people cut out is clearly an airfoil to direct air around the plastic device that holds the sensors.

I dont think air is wirling around inside there especially when you consider its under a vacum.

Jpr5690

iTrader: (13)

Well After Doing It I Can Say My Maf Needs To Be Tuned ... My Closed Loop A\f Is More Irratic And My Open Loop A\f Is .5 Point Leaner Than Before .... I Went To Sd Mode For Ltft Tuneing And My Fueliong Problems Were Solved... Although I Do Think That After Tuneing My Maf Things Will Be Better Than Before...