Just wondering how to descreen the maf sensor? Also is it there really any power gain from this, or is it just a waste of time?

Thanks

Fry

 

Remove the clamps holding your lid and bellows.
Take your MAF and with a flathead screwdriver or pick, carefully insert into the outer portion of the screen and pull out.
AVOID HITTING THE SENSORS AT ALL COSTS.
As for gains, you will be increasing the amount of flow by removing a restriction-fact.
However it can be detrimental if you get a custom tune done to it and fail to mention it due to the preset parameter the computer sees for air metering.
Not to mention it's free and way easy.

 

Its simple. Just push the maf screen off - thats it. Just make sure not to touch the wires/sensors in any way - they are VERY VERY fragile. As for performance - most tuners will tell you that they use the stock maf descreened for optimal performance vs. aftermarket MAFs.

 

This mod is good for 5-7 hp, but it has little to do with increased air flow. Without the screen, intake velocity is reduced, and the PCM is faked into bumping up the timing a few degrees, and that's what gives you more power.

 

i dont know about doing this. i ported mine a year ago adn it screwed up my a/f as well as timing. i then hooked it up to auto tap and it reported up to 9 degrees of KR at WOT! my car ran like **** and actually decreased my HP. this is my experience although some people have different results than me. my car just didnt like it.

 

I remember one of the moderators saying descreen MAF and TB port is safe...but not porting the MAF. I don't get it, How does it reduce velocity to remove a restriction in air flow?

Anyways, I got a question: does maf descreen and ported TB have any adverse effects with a diablo tune?

 

"Without the screen, intake velocity is reduced, and the PCM is faked into bumping up the timing a few degrees, and that's what gives you more power."

I've never witnessed any significant change in timing advance or mixture by descreening a MAF (and I've done a few.) Now porting a MAF, well that's a different story.

Porting the TB will not have any effect on tuning.

 

If you draw the same amount of air through a larger opening than before, the velocity must decrease. Since you haven't changed the engine displacement or rpm, you still flow the same air as before, just at a lower velocity. The PCM detects this and increased the time 2 or 3 degrees to compensate. This may not be enough to notice, but it's enough to yield 5 hp.

 

False. With a descreened maf, you flow more CFM. The screen is there to smooth out the air flow. BTW, porting the MAF will fugg everything up.

 

Cal,

I'm don't want to argue with anyone, but I have a couple thoughts I'll toss out.

The cross sectional area of the MAF is reduced by the screen, but only where the screen is located. I agree that airflow through the screen would have to be faster than the airflow through the rest of the maf (think of filling a swimming pool with a garden hose....water comes out of the hole fast, and then slows down). I also think that the air exiting the screen will immeadiatly slow down to the same velocity as air that has not been run through the screen. The only logical assumption is that the screen "takes up space" and blocks airflow, by removing it, you are removing a restriction and therefore allowing more airflow (think of sifting sand through a sifter, compared to dumping it into a bucket with no bottom in it). These are just some of my thoughts, I'll toss them out for discussion...

Kevin

 

I don't think you understood what I said. I am agreeing with you that the maf will flow more air after being descreened. I'm just trying to dispell a common myth that this is the reason you get more power. Descreening it does increase air flow a slight amount, but not enough to warrant the hp increase we get by doing so.

 

I believe from my observations that descreening the MAF has VERY little to NO effect on MAF readings because the air, at the point of moving across the MAF filaments, has resumed it's normal speed. It's going the same speed across the filaments regardless of if the screen is there or not. IMO, the extremely small gain seen from removing the screen is due to a decrease in pumping losses (elimination of a restriction.)