I jammed a screwdriver through the screen and pulled it out 8 years ago and never had a problem. Sometimes it works, sometimes it doesnt. Either way people will do what they want regardless of what some thesis written by some tool says about the calabration chart and blah blah blah.

 

Maybe someone can do a CFM test with and without the screen one day.

 

Yeah, I seem to remember that a long time ago in medical history there was a guy that got a metal rod shoved through the front his brain in a freak accident. He didn't die and was not affected that much. So, did everyone start experimenting with metal rods and their brains?

...and I really hope you did not call Injuneer a tool. That would not be playing nice.

 

I agree this is personal opinion. I personaly have done it with no issues, and the new 96 ws6 I got also was descreened when I got it...

 

Ok. Just what is the purpose of removing the screen----to provide more air??? What was the purpose of boreing the MAF----to get more air??? If the MAF consituted a restriction, which it doesn't, then perhaps one might see an advantage to removing the restriction or improving the flow by removing the screen, but unless your screen is plugged up it doesn't constitute a restriction. So if your inclined to disagree with the concept of the screen, which appparently was designed with a purpose in mind, then knock yourself out.

However it's been my experience that there are enough things to go wrong with the LT1 without messing with stuff.

BTW, I bought a used MAF for my car, and descreened, honed and polilshed it----looked real nice. Didn't notice any problems, but was advised by one of the tuners here to put the stocker back on so I did.

And guess what----I still don't have any problems. So until it is proven beyond a doubt to significantly provide better performance, I shall give the benefit of the doubt to the engineers. Nuff said.

 

LOL. I should have been more clear. I run 14.7 part throttle closed loop. My engine would be history if I ran 14.7 at WOT. BLM's are the computers way of correcting for humidity, Density Altitude, MAF Calibration, etc. I have mine turned off which means that the MAF calibration HAS to be accurate or I will run lean or rich in closed loop.

 

right on brother

 

i have mine descreened did it 6 -7 yrs ago didnt know any better and buddy (guy who tuned my car) said i was all over the place when he starting tuning the car and he said eric you dont do this i said why he explained but regardlees he did say its not good to do it does through all the calibrations off but car is fine never any problems

 

Descreening the MAf sensor has no positive or negative gains. Descreening it does change the calibration a little but the PCM then changes the fuel trims and that brings it back to the proper A/F ratio, so what ever gain you get is only temporary. Cutting the vane out makes an even bigger difference and thats why tuners ask if you have a ported maf.

The easiest way to tell how much of a restriction the MAF screen is by monitoring you MAP sensor reading at WOT before and after descreening it. Unless you have a strokerwith big heads, you are probably won't see any gain by descreening or porting you MAF sensor.

 

I got a tune from PCMforLess a couple years ago as a base tune. I told Bryan I had a descreened MAF and he said it was no big deal. When I got the tune it had a stock MAF Calibration Table. I still think this Descreened/Mis-calibration thing is an urban legend based on a theory rather than facts.

I have noticed that turbulence in the intake track will greatly affect MAF calibration. I noticed this when I had my MAF on the suckside of the blower and the bypas air was causing turbulence.

 

I de-screened mine back in 98 when I bought my car. I didn't know any better back then. I wouldn't have done it had I been a bit more edjamacated.

Although it's never caused me any ill effects, I still wouldn't do it.

 

I always replace my screens in the Spring when we open the windows, the wife likes to air out the house...If you descreen you'll let bugs in your...oh, errr I'm thinking I'm thinking about different screens...

--Alan

 

This is not the way I was taught(in GM driveability school) how a MAF works. A GM MAF anyway.

A MAF does not measure the temp of the air coming into the system, the AIT(air inlet temp) does that.

A MAF uses a heated wire, the ecm measures how much voltage it takes to keep it at "X" temperature, the more air that goes across the heated wire the more voltage it takes to keep it at "X" temperature...with this it looks it up in whatever table it needs to along with the info from TPS, MAP, coolant temp, AIT and o2 to give fuel.

If what this guy says is correct, putting a CAI on will mess it up.According to him.


David

 

Yes that is correct. It produces a signal based on how much voltage is required to maintain the sensor at a certain temperature. Thats is why it needs an air temp sensor in close proximity to the sensor, to give it a base point. Thats how GM does things, or atleast how they did it when I was in college. Some manufatures like Bosch build the air temp sensor right into the MAF sensor and is why those sensors have 5 wires

 

Funny, that quote was extracted from my online Scanmaster guide, which many people have found to be helpful. If you feel that providing an online reference document that has been used by countless people on this site and others over the past 7 years makes me a "tool", so be it. What have you done for the F-Body community lately?...... blah blah blah.

You're missing one point that is covered in the writeup. The MAF has to measure the temperature difference between the incoming air and the air heated by the wires. It holding the delta T at "X" degrees, not the wire temperature. Only by knowing the delta T can the MAF do its calculation converting the amount power (not the voltage) consumed to heat the wire to the equivalant thermal energy transferred to the air. It knows the specific heat of air (BTU/#/degF), and it knows the delta T (degF). All it needs to calculate the mass flow rate (#/HR) is the total heat lost through the wires (BTU/HR), using the wheatstone bridge circuit that heats the thin-film conductors.

In effect, the car has two IAT sensors. The one in the LT1 MAF is used only for the MAF internal calculations. GM realized that they were spending money on the two sensors, when only one was needed, and has since changed the design of the later LSx MAF sensors to contain the only IAT sensor, and to use it to feed the PCM and provide the internal data for the MAF calculations.

The IAT does not work with the O2 sensors to control fuel, at least not in a mass-air setup. The MAF measures the mass air flow, and the PCM uses that number and the target A/F ratio to calculate the fuel mass flow rate. This is different than the speed-density system, where the IAT feed to the PCM is a critical part of the data the PCM requires to calculate the "density" part of the speed-density equation. Hence IAT has a major impact on a speed-density system, while it is use for very little in the mass-air system.