Ok, bare with here this is my first vette..on order.

With the TA and LS1 motor we would pull the MAF and remove the honeycomb screen to increase airflow. Some folks believe the screen was there in case there was a backfire i.e. it would prevent the air filter from catching fire.

Does this screen exist on the LS2? If so, has anyone tried removing it so see of there is performance improvement?

 

The screen does exist and I was debating doing it to my car. The issue is that when I did it to my 2001, I lived with a throttle hesitation while driving in which the car would hesitate then surge mildly when going from coast on the highway to a roll in throttle. I posted repeatedly but no one could help me with this issue. (at least none of the tuners I was close to in NY would chime in to help). Chris from East Coast Supercharging - a great bunch of guys there- however did mention that I should run the Z06's MAF airflow chart and I copied the values into an LS1-edit file and it got rid of the surge. The car obviously saw a difference in the MAF w vs without the screen and I would imagine that anything that increases airflow would be good. Just be sure to mention the airflow chart when you get an edit tune or do it yourself.

I should mention that I did port the throttle body at the same time I removed the screen but the adjustment to the maf file fixed it so I am assuming that it was the screen and not the TB. I may have just increased overall air-flow and that is adjusted in the same table.

I say wait until you can get a dyno tune but the drivability issue wouldnt be noticed by most people. My friends said it was so minor they wouldn't have picked up on it but it was enough to move my head back when it did it so I kept searching for a solution.(****)

The air filters catching fire is just silly to mention...not gonna happen.

Drive safe.

 

It seems I remember reading several posts about this - I believe from a couple of tuners.

The opinion was that if you remove the screen on the C6 you would get a "Check Engine" light and it would start throwing codes.

I don't know if that's what would happen or not. If you try it, let us know what happens. If LS2 Edit was more widely available I'm sure you could program it so it would be okay without the screen.

Bob

 

I heard that the screen smoothes out the air turbulence for good sensor
readings. Any one else?

 

Interesting...

 

All your questions are factaully answered at www.ls1howto.com click on C5 MAF conversion.

The MAF requires a computer recalibration if you use an uncalibrated MAF. Not possible with LS2's yet so dont do it until you can dyno or it may throw a code for airflow.

There are 3 different values for the MAF depending on the year and if is has a screen

The graphs are seen in JMX's awesome web page...click on this:

http://www.ls1howto.com/index.php?article=25

 

I have a c6 and i took out my screen right when i got it i havent had any problems at all with the car it justs add some hp not much. Better air flow i think, that screens there so nothing gets in the intake.

 

The honeycomb laminar flow screen is there to provide more accurate fuel trims.

The PCM is a dynamic computer, which continuously adjusts the amount of pulse width to each fuel injector, based on the O2 sensor readings.

The MAF sensor is somewhat accurate with the screen, and less so without it. In fact, the turbulence at the wire pickup, without a laminar flow screen plays with the 19 or so fuel trims, causing inaccurate readings and the O2 sensors making up the difference between the MAF readings and the actual O2 level left over during the combustion process.

The point of the O2 sensors is to accurately re-trim the air fuel ratio back to 14.7:1 (stoichiometric) in all fuel trims. Each trim has a corresponding throttle position. This constant re-trimming is what is known as closed loop cycle.

During WOT and heavy load, the cycle breaks from the 14.7:1 closed loop mandate and goes into "open loop" This is the 12.3:1 air fuel ratio or PE Mode (Power Enrichment). The extra fuel helps prevent spark knock, and is set too rich for good power. 12.8:1 to 13:1 is the best a/f ratio, assuming your octane is high enough to prevent knocking.

Removing the screen will probably increase hp at very high rpm due to the pressure loss recovery of having the screen out of the way of the airflow, but you may end up with poor fuel trims due to the turbulence issue. The C6 intake is so poorly designed, that the screen is important in keeping the turbulence at the wire pickup down.

Now if you could design an intake that eliminates turbulence by having a straight 100mm shot at the throttle body, you might be able to remove the screen and still keep from tripping lean codes.

Jim Hall
Halltech

 

i took mine out and haven't seen the "check engine light". I have also cut open the tops of the air filter covers, left the "extra" cover in place, and added a little spacer under the "extra cover" to lift it up just a bit. no problems thus far.

 

Some folks, ahem, dont know what laminar flow is. Cough, cough, perhaps you could explain it for them?

 

That is where the airflow is smooth, straight and is in one direction, at a constant velocity, in a confined space.

Here is another definition:

http://www.aeroplanemonthly.com/glossary/glossary_L.htm
and
Found this online. The reason for the honeycomb:

"Because of the small size and fragility of the wire, hot-wire anemometers (Mass Airflow Meters) are susceptible to dirt build-up and breakage. A positive consequence of their small mass is fast speed of response. They are widely used in HVAC and ventilation applications. Larger and more rugged anemometers are also available for more demanding industrial applications. To ensure the proper formation of the velocity profile, a straight duct section is usually provided upstream of the anemometer station (usually 10 diameters long). A conditioning nozzle is used to eliminate boundary layer effects. If there is no room for the straight pipe section, a honeycomb flow straightener can be incorporated into the sensor assembly."

I spoke to Delphi three weeks ago about the new Probe MAF being used in the C6 Z06. I was told that they did not get the contract for that sensor, but Hitachi's Probe MAF got the deal. Why? The Delphi unit was too restrictive I was told.

 

OH,..........wow,... cheeeeeeeeeeeze, ........IM LOOSEN IT ! ,,,,,,,, Imput overload, I gotta pull over my head hurts.......................

 

i haven't noticed any aftermarket performance MAFs (granted there aren't any for the c6 yet) with the screen. I also heard that on the c5 Z06 didn't have the screen, maybe that's incorrect but that's what i heard.