cobaltguy889

Ok, here is my dilemma. I'm doing a custom s20g turbo kit, and i basically have everything except a bov and boost controller.

My question for you guys is, whats the best way to go about the MAF Sensor? I know that If I stick with 2.5" piping all the way around, i'm going to max out the maf. So then do I put the maf in 3" piping right before the Throttle body?

My other thinking was, if there was a way to "relocate" the maf sensor to the Intake part of the turbo (before the air becomes compressed, right after the air filter) then I could keep it 2.5" piping, and run a normal atmospheric bov, instead of a recirculating, and then make tuning easier?

What have you turbo guys done?

Any thoughts or ideas appreciated

ShortStack

You should run 3" all the way through on the MAF side.

06blackg85ss i believe messed with moving the maf...

b_faulk75

I don't have an answer for you, but i was wondering the same thing, i have a custom boosted L61 that is having tuning issues, i am thinking of expirimenting with the maf placement... I have my maf mounted in 3" piping 10" before the tb, the car runs great ev erywhere but idle, at idle it fluctuates up and down and i keep getting lean fuel trim readings, but only at idle, and there is NO vacuum leak....
iI am thinking my problem may have something to do with the maf...

cobaltguy889

the problem with going more 3" piping is that there is going to be more lag...thats the dillemma that I'm having...

bolus

I'm obviously set up differently than how you'll end up but I have the MAF right after the air filter in a 3" tube before the turbo. I have plenty of room before maxing it out and it seems to be happy with the airflow here

ShortStack

The lag difference will not be noticable If you use 2.5" piping before the intercooler and 3" on the side with the maf.

2K5SS/SC?

Run 2.5" pipe all the way except for the last 8-12". Flare it from 2.5" to 3" and put the MAF in the 3" spot.

Maxim_X

^^ That's what I did. All of my piping is 2.5 until the last strait section after the IC where it turns to 3 in. and it stays 3 in. to the throttle body.

I wouldn't try to run the MAF before the turbo.

cobaltguy889

The reason I was thinking about running the maf before the turbo is because then I can run a normal atmospheric bov and I won't have to compensate for the released air by running a recirculated bov.

are you running a recirculating or an atmospheric bov?

Thats what I've planned on doing from the beginning, i've just been wondering if there is a way to keep it 2.5" all the way through.

ShortStack

My Maf is on the 3" side of the intercooler and im running an atmospheric..

Maxim_X

Your thinking opposite. When you place the MAf in the charge piping after the BOV then you don't have to compensate for the air being lost.

cobaltguy889

ok. I guess that makes sense. From what I have read about maf sensor vehicles, you need to run an atmospheric or the maf will spike, but I must have misunderstood. Good to know.

So If i put the bov on the hot side of the piping (there is no point in releasing the cooled air right?) and run the maf in 3" piping right before the throttle body, everything should be dandy.

ShortStack

Yes.. As long as the MAF is in 3".