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*Jeff240sx* · 10-06-2004, 03:13 PM

Great question!
That's called blow-through maf, as opposed to pull-through like we all use. Pull-thru is when air is pulled by the motor, or the turbo. Blow through is only done on boosted engines.
These setups seem to be hit-or-miss as far as functionallity. In theory, if you setup a blow-thru and tuned it, it would work wonderfully. The main advantages of this type of MAF is that you can run open-atmosphere blow off valve without the instant-richness that is associated with a pull-through setup. This is because the air in a pull-thru is metered, compressed, and put in the intake piping. The BOV dumps it, but the motor is ready for all that air, and adds fuel. With a blow-thru, the air isn't metered until further down the charge pipes (the closer to the TB, the better to an extent), and bieng vented through the BOV won't affect the a/f ratios. Another advantage is that you can eliminate alot of intake piping and couplings associated with the pull-through maf infront of the turbo.
Disadvantages are making piping for a 80mm z32 or slightly larger cobra maf. The z32 maf I would expect to explode under pressure, because it's very thin, brittle plastic. The Cobra MAF is 3.5" inlet, and 3" outlet, which makes setting up the piping a bitch.
-Jeff

10-06-2004, 03:13 PM	#39
Jeff240sx I hate you too... Join Date: Jul 2001 Location: Tampa, FL Age: 41 Posts: 5,828 Trader Rating: (0)	Great question! That's called blow-through maf, as opposed to pull-through like we all use. Pull-thru is when air is pulled by the motor, or the turbo. Blow through is only done on boosted engines. These setups seem to be hit-or-miss as far as functionallity. In theory, if you setup a blow-thru and tuned it, it would work wonderfully. The main advantages of this type of MAF is that you can run open-atmosphere blow off valve without the instant-richness that is associated with a pull-through setup. This is because the air in a pull-thru is metered, compressed, and put in the intake piping. The BOV dumps it, but the motor is ready for all that air, and adds fuel. With a blow-thru, the air isn't metered until further down the charge pipes (the closer to the TB, the better to an extent), and bieng vented through the BOV won't affect the a/f ratios. Another advantage is that you can eliminate alot of intake piping and couplings associated with the pull-through maf infront of the turbo. Disadvantages are making piping for a 80mm z32 or slightly larger cobra maf. The z32 maf I would expect to explode under pressure, because it's very thin, brittle plastic. The Cobra MAF is 3.5" inlet, and 3" outlet, which makes setting up the piping a bitch. -Jeff __________________ Whatup?