I was simply curious as to why this is done? What is the purpose behind it? Thanks in advance

 

people say that it will flow better
the screens are there to straighten the air flow so your computer
can read it properly
i myself do not recommend this but other will have their say

 

If you are even thinging about doing that crap to the MAF, one word of advice "DON'T".

 

I've taken then out plenty of times- no bad results, minor power increase even on a stock motor. The screens on a 3rd gen MAF don't do crap to straighten the air- they aren't directional vanes like the screen in the front of a 4th gen MAF- they're screens like on your back porch. What would be the point of putting a screen on back of the sensor like a 3rd gen MAF has if they were there to straighten the air? Notice there is no rear screen on a 4th gen MAF which DOES have a straightening front screen.

On a 3rd gen they're there to keep stuff from touching the insides of the MAF which could damage the fine wires, etc. That's all.

You remove a little metal snap ring from in front of the screen- it's tough to get out- a small screwdriver and needlenose pliers work OK for this- and then drop the screen out.

 

This is what I've read about the screens...

Without the front screen the airflow is more laminar, and therefore has the highest velocity in the center of the duct. It is possible, under the right conditions, for this velocity to be above the calibrated limit that the MAF can handle. With the screen in place, the airflow is more uniform across the diameter of the duct and this is what the MAF was calibrated to see.

As for the rear screen, it may be there to "cushion" the shock of a backfire so the thin wire doesn't break.

In any case, the MAF (with screens in place) has plenty of flow for most engines. Only when you get up over 300 HP will the MAF flowrate be a consideration.

 

I like the post from Damon "I've taken them out plenty of times" does this mean he replaces his MAF for bad performace frequently on descreened ones?? I only replaced a stock Maf once in fifteen years.

 

I have had the screens out for at least four years now with no problems (same MAF all that time). I did think that there was a seat of the pants difference when I did that and the other no cost mods like modifying the air box and relocating the air temp sensor. Can't prove it though.

 

Every car I've ever owned that had a MAF, I took the screens out with zero ill effects.

If the screens were totally necessary and were there to straighten the air, why then did GM remove them from the Z06?

 

I wouldn't post that I had taken them out many times unless I had. I'ts been a worthwhile mod every time I've done it. Never had any bad results.

Now I said about later model (4th gen-) MAFs actually having a different screen than the old 3rd gen MAFs and that might cause some problems in some situations. I'd like to add to that the fact that I removed this screen on my own 94 Formula ALSO with performance benefits and no bad effects. And I still use the tortured stock intake plumbing before and after the MAF. This mod along with other "free mods" got my Formula from running 13.7 @ 103 to 13.5 @ 105. So even on these later ones it seems to matter very little if you take it out. It's just that the screen on the 4th gen MAF is definitely there to help straighten ariflow, while the ones on the 3rd gen MAF are just there to prevent damage to the internals.

 

Yep, the screens on the Bosch unit are there to protect the sensor wire. They become a restriction for anything over a bone stock 350 so take them out if you dare/really want to. There is absolutely no comparison between the 4th gen sensor and the 3rd gen one aside from them being on F-bodies. It will be more prone to suffering damage with the screens out, but if you actually have an air filter on it, it should be fine. But swapping to the Speed Density ECM setup will be the best fix for any MAF TPI issue....

Also, moving the MAT sensor an a MAF TPI is useless. The sensor does nothing for changing how the engine runs per air temperature aside from verifying the proper operation of the EGR valve for DTC 33.

 

If you want a better flowing Maf then a stock (descreened) one buy a WELLS MAF. Flows more then the ECM can calulate and less problems (descreened one). Cheaper, better design (only one screen ) and a film element instead of the Bosch's hot wire
(crap) and a better all around replacement for your screwed up Bosch descreened ones.