[RESOLVED] GM MAF - remove mesh or not?

[soldave]

Quick GM MAF question for you folks. Will be running the MAF in blow-through mode once it's all set up and installed. I'm going to cut the metal dividers as suggested but was wondering if I should keep or do away with the mesh that's in front of the sensor wires. It is a protector I suppose but then there shouldn't be anything in the airflow post-turbo that could hit and damage the sensor anyway.

So should it stay or should it go?

 

[snowborder714]

The mesh is actually to help guide/direct the airflow.
http://www.dsmtuners.com/forums/bolt-tech/97735-gm-maf-blow-through-screen-no-screen-better.html

 

[turbo90gsx]

The screen is there to straighten airflow across the wires. Removing it will give you even more strange airflow readings and will probably cause the car to drive strange.

 

[1992awdlaser]

Take it off. What is the purpose of the gm maf on most car? To eliminate the restriction of the stock maf. Why are you going to restrict what the gm maf can flow with the screen? I have no problems driving/tuning my car without the screen or divider.

Removing it will give you even more strange airflow readings and will probably cause the car to drive strange.

You're wrong. And please don't post what you think will happen, only what has happened with you.





Nobody on the link forums has a problem without the screen in, including myself. I also have to add that there has to be a smooth and gradual transition into and out of the maf from the intercooler pipes.

 

[1992awdlaser]

Yeah dsmlink uses airflow smoothing to "fix" the inaccurate signals that a gm maf gives in blow through mode... you don't know you have a "problem" because the real airflow values are being "averaged".

I don't know about V3 but with V2 that is only true when you have "Use MAP" enabled without having "FakeMAF" enabled. Enabling "Use MAP" without having "FakeMAF" enabled just turns on a smoothing function for the appropriate input (MDP on 2Gs and EGR temp on 1Gs) with V2. Without "UseMAP" enabled there is no smoothing with V2(not sure about V3).

There are many people, myself included, that still use V2 and don't use the "Use MAP" option. Therefore, my statement still holds true.

 

[Aaron91RS]

The LS1 owners(hey that's me) are smart enough to tell other LS1 owners not to remove the screens because it messes with the calibration.
So now you're taking a device that's needs to have screens on it's intended NA application, removing those screens, installing it on a pressurized blow through system with a computer chip converting the signal to something the dsm ecu can understand, all because you have some crazy belief this screen that's not a restriction on a 400-500hp na ls1 is suddenly a restriction on your 350hp turbo dsm?

k just so we're clear.

 

[TRBOBLU]

My 3" GM maf is in blow through, no screen, and no metal divider. Fuel trims are excellent(within + - 3% on old style 1600's) and boost est vs. actual boost is within .5 psi or under at 100% VE. Car traps 130mph on 30psi and stock 2g timing(ie no additional advance) with a PTE SC6169SP. So to those that say your tune is just covering up the problem is rediculous. I think my DSMLINK logs would prove that my tune is better than most peoples stock cars from the factory!1

 

[TurboSportAWD]

If you look at aftermarket GM MAF's like those made by Granatelli, they do not have screens. If your sensor is in a straight section of the piping then airflow should be laminar with negligible turbulence..

 

[dsm-onster]

^^^^ Yep. They are proven. Imagine a maf that has the same resistance to flow as a speed density setup! , no way. Best of both worlds. No need to tune for something as simple as an o2 housing upgrade, but still zero resistance to flow before the compressor.

Lol... so wait... are you CONFIRMING that a gm maf w/ the screen removed is out of calibration and cannot give proper signals for accurate airflow readings....

Dang dsm wisemen... The screen makes the air flow laminar (predictable and easy to read)...

He's saying that dsmlink allows you to reconstruct the transfer funtion for the maf with the screen removed. There have been no issues with predictability. pretty simple .

If link makes the dropped counts and random spikes that you're supposing would happen with removing the screen, then all the more credit to link. It makes a bad maf function like it should. Again, he's said no one has had any issues. And, guaranteed, some of these guys have made twice to 3 times the power you have .

Bottem line is that the guys who've actually used a gm maf without the screen have spoken about what the results will be.

. . . .And anyone who would think that a screen over an intake pipe isn't a restriction should leave their stock airfilter and air can on their intake. It's not just a screen it's hundreds of tiny tubes the air has to travel through. There's a huge difference in laminar flow with running one large pipe vs. 2 smaller pipes that total the same area; favoring the single pipe. Viscous resistance is very detrimental to flow. Speed density does allow noticably more flow at even moderate power levels.

 

[Boosted98gsx]

In regards to the OP, do not remove the mesh, it is there to laminarize the airflow across the maf so that even airflow distribution can allot more accurate measurements.

In regards to the maf being a restriction; OF COURSE IT IS. You have MASS in the way of air = restriction. How much may be up for debate, but I would wager that if you took the honecomb mesh out, and compacted it flat cross sectional wise (perpendicular to airflow) you would find at least 15% of the cross sectional flow area to be obstructed. That's theoretically 15% (or more) more airflow that you could have if you eliminated the MAF altogether.

 

[soldave]

Well it's pulled out so I'm gonna go without for now. If I get really bad performance when it finally gets fitted then I'll put it back in again. The mesh has a few marks and dents on it from my questionable handiwork, but we'll see how it goes.

 

[ApexVIII]

The mesh is actually to help guide/direct the airflow.
http://www.dsmtuners.com/forums/bolt-tech/97735-gm-maf-blow-through-screen-no-screen-better.html

thank you!

please do not remove the honey combs they are there for a reason,

 

[Defiant]

It apparently won't matter. Run it as you like.

I swear to christ, it's like a ladies' sewing circle in here sometimes.