I've seen at least one individual who was able to correlate the removal of the screen with a 2.5mpg loss in fuel economy. Hard to understand how it could be that bad, but he had the numbers, and claimed he could swap the screen in and out and track the change in mileage.

The screen will obviously have less effect than cutting out the "wing" and the plastic element supports. The factory removed the screen on the 2004 (and possibly earlier) Z06 MAF, and claimed it netted 5HP, but that's on a 400HP engine. The thing that allowed them to do that was the fact that the Z06 intake duct was symetrical, and provided uniform flow without the screen. Compare that to the stock F-Body LT1 inlet duct, with its variable cross-section and bends, and you can see where its not going to contribute to uniform flow.

One thing with the screen removal.... the early MAF's have a spring ring that allows you to remove the screen without breaking it. Take it out and see what happens... might work, might not. The later MAF's have the screen fixed in there, and require destroying the screen to remove it.

 

The calibration may be off but I've never had a problem with any of my ported MAFs and all the cars I've ported them on have been fast for the mods. LT1, LS1, L67, I always port my MAFs. LT1 went 12s@110mph with bolt ons, LS1 12.6s@112-113mph with stock exhaust manifolds, L67 13.5s 100-101 with a 3.4 pulley and homemade DP. All home ported MAFs. Plus I'm an awesome driver

 

Thanks Injuneer. Well I dont feel so bad now. I actually couldnt stop thinking of getting a new MAF when I went to bed lastnight, hahaha, and just took the last mileage per tank that I just filled up and I got 17mpg in the city, and last weekend I ran 215 miles at 70+ on exactly half a tank, and thats about 30mpg (with the a/c on)!!!! I guess I will leave it the way it is, but I notice a gas/exhaust smell when I really get on the car and totally thought I was running rich. I just bought a proscan tool.....I will see if it tells me the f/a ratio I am running, thanks---

 

great thread subscribing, i too have removed the "screen" and wonder if this could contribute to a bit of richness nothing to serious just some what rich.

 

Don't panic you will be fine and you have not wrecked your MAF sensor. I did a test on my 383 less then two weeks ago with Thunder racings MAF end (Basically ported end with no screen) and my stock MAF ends. I used TTS data master and recorded part throttle data and there was only a slight difference between the two it ran a bit lean with the Thunder racing ends but the difference was very small about a 2 BLM difference is some places. Now with that said this also proves in my mind at least that porting a stock MAF sensor does nothing to improve performance other then possibly high RPMs at WOT. I would have to run the same comparison on a dyno to see for sure but I do have my part throttle data and that was enough to make me just slap the stock ends on and call it a day. In the end and I don't think it has been mentioned is I don't think the change is a linear so you would have to look at the entire range of the tune part throttle and WOT under varying load conditions. Keep in mind that many tuners change the MAF tables to add or subtract fuel in a certain range so I can’t see why so many say it makes it impossible to tune, look at the A/F, RPM , and MAP readings and change the darn MAF table a needed. Again this data is only for my engine and my combo but I am running the stock ends because I saw mo benefit but I didn't see a big problem either.

 

After reading what everyones put and some of my input, I went out today and got a used stock MAF from a junkyard for $25 big ones. Screen, fins, sensor and all. So now i have a ported one, and a stock one. I'm going to try both and see if I notice a difference in either.


ShibbyZ

 

Now there is a good idea...and you porting time will not be wasted, but rather used for some good research.

 

Thanks, once i get my tranny working again i'll check for these things

-Noticeable throttle response
-Gas mileage (up or down)
-Any noticeable power (99% sure no)
-Any other kinds of defects or odd things worth mentioning


ShibbyZ

 

Yeah Please Keep us posted on your results. This is one of those topics that always gets mixed responses. I still don't know what I think about it because there are very good arguments for the opposing views. Not just on this message board ... also in magazines etc.

Your findings would be interesting.

 

Are those maf's basically the same as ours (the factory z06 ones with no screens)....well besides it having no screen stock, lol.....thanks---

EDIT: also will the screen being taken out of our maf cause an SES light to come on?!

 

I've just recently swapped my stock maf out with a buddys descreend one. I did notice a few minor things, I have yet to scan it to look at my blm's though.
- My SOTP meter felt maybe something at the higher rpm's. This could easily be all in my head
- I think I lost some part throttle response during normal driving. This is pretty for sure right now.
- Gas milage seeeems to be as bad as it's always been It's hard to say with all the city / hwy driving I do.
- My other friend who had a rich condition and scanmaster in the car noticed his BLM's shifted closer to where they're supposed to be now with my stock maf in his car.

The Z06 MAF is calibrated a bit differently then stock. I believe the MAF tables for the computer can be found on the net somewhere. I personally opt'ed not to run the Z06 MAF because I'm just paranoid about the sensor not getting an accurate enough reading after my CAI's turbulence. (Z06's have a much straighter intake than ours). I know there was someone on this board who had a Z06 maf with the right tables and said its been working great for him

 

Mine doesn't have a screen, and I didn't notice anything bad, and I felt a slight sotp increase in the upper rpms.

that's about it. gas mileage stayed the same - bad. course that might also have to do with my lead foot

 

I tried the ported maf by doing the porting today.
my results are: definitely better throttle response....louder intake suction sound....terrible idle......and check engine light came on(after 20 minutes driving around)...codes were bank 1 too lean/bank 2 too lean.......bought new unit ...replaced ...al went back to normal.
my conclusion.......waste of time as well as replacement cost !!

 

An old thread, but for sure don't ever screw with the MAF housing.

Leave the screen in it and the housing stock. Porting them will change the calibration drastically and if you don't re-characterize it in the PCM properly, it will give you all kinds of problems.