Stock Maf Limits

BBRSpeedWorks

Well in the gtr forum's going from 2.75 to 3" dropped the readings from 4.91 to 4.6 but retuen well be needed. Also the gtr maf's well work in the 370 but not sure yet if there any better

phunk

But they are using them pull-through, right? If they are using them pull-through and getting HP that would be high for a 370z, then they might work out really well for us in a blow-through application.

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BBRSpeedWorks

I have confirmed the are the same part number and I believe they are pull thru I'm waiting on My contact from nissan to give me a call back. But the gtr can make up 800 whp on there maf's so I think that mite be the ticket. If so I well be grabbing them for $150 a piece can't beat that. I remember still en saying that they contacted nissan and got a pull thru maf's for there s/c kit...not sure I'm still researching...

phunk

Same part number as what? As the Z? if so, that would be no good

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BBRSpeedWorks

I'm sorry i ment style

BBRSpeedWorks

nope they re the same part number i was guess my typing was right the first time. sorry

Mitco39

Ill just go by the Nissan dealership and pull some off when they aren't looking. If they are pull through like charles said and were now using them to blow through then they should work perfectly for our situation.

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2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

BBRSpeedWorks

i know for fact the 3" charge pipes well help you and i hope the gtr maf's come thru...when the new charge pipes you well need to re tune cuz ur start running a lil lean

Neo187H

Same part number means the same part, it would be a waste of time swapping in the "different" MAFs. Looking for other differences between the two cars would be much more productive, stuff like the larger intake piping that has been mentioned.

BBRSpeedWorks

That's what I'm doing on my kit is bumping it up to 3" charge pipe so I won't have this problem

Nissan370

with the vsr turbo kit my tuner told me my maf is maxed out also.
at 10-10.5 psi so my only option is uprev maf 700.00

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370z vsr motorsports single turbo/built motor 9.1cr 525rwhp/450rwtq @ 10.5psi (stock maf maxed out)

Mitco39

You always have 2 options.

1. Different MAF
2. Larger diameter piping your sticking that MAF into

or actually there is a 3rd that I became aware of
3. Using a spacer to move the center of the MAF closer to the sidewall of the boost tube.

__________________
2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

TopgunZ

So what actually happens when a MAF is maxed out? How would you know if your tuner wasn't watching it? What if you just threw more psi at it then the MAF is capable of?

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ROTREX SUPERCHARGER TUNER KITS - $6799/ CUSTOM STILLEN AIR TO AIR KITS -$2100/ 700+ WHP!! WWW.TOPGUNSPEEDWORKS.COM

Mitco39

Well it stops being able to measure the air over a set value. Lets say this maf maxes out at 80 lbs/min of air. The engine is using this "metered" air to determine how much fuel to inject during open loop operation (under load). All is fine as long as the tune is such that the amount of air going in is correctly matched up with an amount of fuel going in.

But now what happens if you run 90 lbs/min of air. Well as far as the computer knows your still only running 80 lbs/min. So it injects enough fuel to satisfy 80 pounds not the 90 your are running. So you start to lean out. And leaning out will only last a short time before you detonate and pop the engine.

If your tuner wasnt watching it you would see it on the dyno during a WOT run, look at your AFRs, if they appear to lean out as your rpms increase then you could very well be seeing the limits of the MAF (of course this is invalid if the tuner for whatever reason leans out the mixture via the target tables or if your actually draining your fuel rail).

That would be the easiest way to catch it without having access or seeing a log of the car.


For me right now I am running very rich so that when I hit the limit of the MAF I still have more than enough fuel to satisfy the burn. Its unsafe but as long as boost stays consistent I can have some safety in it like this. Still very undesirable and that is why I am looking to fix this issue.

__________________
2007 Chevy Duramax - EFILive Tuned By Me
2010 40th W/ Nav - Boosted Performance - UpRev Tuned By Me
The Mrs. Ride -2012 335XI N55 BMW - Cobb Tuned By Me, Built by her
My Build --> http://www.the370z.com/members-370z-...39s-build.html

TopgunZ

Thanks for the explanation Mitco. I need a fix for this also!! I was planning on running 14 to 16 lbs.

__________________
ROTREX SUPERCHARGER TUNER KITS - $6799/ CUSTOM STILLEN AIR TO AIR KITS -$2100/ 700+ WHP!! WWW.TOPGUNSPEEDWORKS.COM