Best GM MAS set-up Options

[KOU In3]

I've done a lot of the reading but I'm curious of the opinions from those who have tuned with them. What do you think is the best GM MAF set-up. Basicly the options are those below:

3" drawthrough
3.5" drawthrough
3" blowthrough

Second question. To descreen or not? I would think there would be less restriction without the screens but I'm thinking the 'straighter' airflow might be better. I've read lots of opinions but no definative data there either. Anything out there from you guys that have been all over the yahoo groups?

By the way, as you might expect, this is a sheer performance question. Not interested in venting for it's own sake. I'm leaning towards a 3.5" descreened draw-through set-up at this point but could easily be swayed.

[natedogg]

I have done both the 3" and 3.5" (3.5" is my current setup) drawthrough and both seemed equally tuneable and accurate.

There is still a debate as to which setup (drawthrough or blowthrough) is better. Zach's assessment for blow-through is fairly common and makes good sense. I'll go ahead and add a different point of view to the table. One thing going against blow-through is that the pressurized air after the turbo has a stronger laminar flow. This can theoretically make the blow-through setup less accurate for two reasons. One, since the high pressure tends toward the outer edge of the pipes, going abruptly from a 2.5" pipe to 3" MAF sensor can cause some nasty turbulence and cause more or less air to be read than should. Two, since the higher pressures tend toward the outer edge of the pipe, that air on the outer edge is moving faster than the air toward the center of the pipe. This too can theoretically give false MAF readings.

That being said people, like Kris, have done blow-through and have had great results. Other people have tried switching to blow-through and have had not so great results. Buuut those people may not know what they are doing. I think it just comes down to personal preference, how much work you want to put into it, and how loud you want your BOV to be.