As everyone probably knows, there has been an on-going back and forth on the removal of the MAF screens. Some say it's the greatest thing since bubble-gum (like TPIS) and others say the opposite.

I removed my screens and heat sinks from my MAF a long time ago, but just to see if there WAS any difference, I used a piece of window screen to cover the inlet portion of the MAF. I used a heavy duty rubber band to hold it in place while I slide it into the air filter housing. I left the rear most opening of the MAF open (no screen)

Well after driving the car for a while to allow the ECM to learn the new airflow, the drivability improved dramatically. Idle was smoother, part throttle response crisper and it seemed like there was an all around improvement in low speed/cruise performance.

Score one for the "Don't remove the screens" crowd.

Now the latest mod:

Since the screen does inhibit total, WOT airflow, and since we know how important airflow is to power, I decided to try one more mod. None of us wants to be caught on the interstate by a 'hopped-up' mustang with our airflow restricted, right?

So I removed the screen I'd installed (it had been on for about two months and looked identical to the way it was when I installed it). This time I used a piece of aluminum screen "patch" from ACE hardware and two part epoxy to epoxy a piece of screen to cover just opening to the heated wire sensors.

My thinking: Could be that the screen does straighten airflow (as some guys claim) and is needed to give the ECM better flow info. So if I cover only the "half-dollar" size opening in front of the wire sensors - leaving the remainder of the MAF open - I may get the best of both worlds.

Minimally restricted MAF air flow while maintaining straightened airflow to the MAF heated wires.

Right now I'm waiting for the epoxy to cure. Then I'll drive the car over the next seveal days to see if this trick works.

I'll post the results.

Jake

 

Jake

Try running a modded MAF sensor and a stock one at the track on the same day. Let's hear the results in ET.

I have done this experiment.

Vic

 

Vic, did you get any codes when you experimented? I tried switching from modded to stock MAF at the track for testing. Every time I put the stocker back on, it would throw the MAF codes. So I never did get an honest comparison.

-John

 

I never got a code with either MAF sensor.

Not sure why you are getting a code. Are you sure both sensors are in good shape ?

BTW, I picked up .1 in ET with the Gutted MAF sensor.

Vic

 

My stock MAF is new. Only used it a few times, could'nt have put more than 5 miles on that one. Maybe I should get off my butt and test the thing and see if it was bad out of the box. My MAF system acts too fragile sometimes. I've gone through 2 sets of relays already. :rolleyes:

-John

 

I'm not a fluids specialist but am familiar with the science.

I am guessing creating a screen just for the area of the sensor wires will cause inaccurate readings, possibly even more so than with just the screens all together removed. Fluids, (like Current) flows in the path of least resistance. So the screen will abnormally cause more air to flow around the sensor wires (I would think worsening its ability to measure actual flow)...

As I understand it, those who gain from the MAF swap largely due to one of two things.

If a relatively stock car (no top or bottem end mods), the MAF swap is a gain since the PCM is being tricked. It isnt additional air flow that is reaping the extra HP, it is a leaner mix. The mod'd MAF is telling the PCM that less air is passing by it, causing the PCM to lean out the mix, thus boosting HP cause stock LT1s run rich. Question then becomes, which leans the mix to the optimal point more effectively - a MAF without screens or a MAF with screens in front of the sensor wires only........ hmmmm.....

Second gain is when you have a correctly calibrated mod'd MAF and your car truly does need the extra air flow. Most who have rebuilt top and/or bottem ends have reprogrammed their PCM already. Depending on the programmer, some have them tweaked to the nth, others just moderately. But as always, there is room for improvement. Thing is, experts (such as Ed Wright of Fast Chips) leave a little on the table for sake of durability. Ed's programs for instance are tweaked as close to prime as possible while not getting it so lean that it fries things due to temps. It is very possible to get a testosteroned motor too lean. So even Ed's programs can be tweaked to provide an additional few ponies, but you wouldnt want to drive it all the time like that - unless your car is a track only machine...........