Thom

Hi all,

Since the compressor cover on my turbo is 4" I am considering fitting 4" piping all the way to the turbo.
As far as I have observed, people who have run 4" inch piping use engine managements based on MAP.

Since I run a Vitesse set up as I was wondering what kind of work would be needed to fit a 4" MAF - assuming there is a such a thing as a 4" MAF sensor, as I have not yet seen a production car fitted with one.

Thoughts?

TIA

fast951

If you can physically fit a larger MAF , I can get you a MAF around 3.5-4", and you will not have to make any changes to the software. email me directly for details.

toddk911

I run a 90MM MAF (about 3.5") and depending on where/how you mount it will fit behind the headlight with removal of the headlight stoping bracket.

And if you have your piping slightly downward into the "headlight well" area, you could mount a much larger MAF.

Thom

I will have to take some measurements first, but thanks for the feedback so far!

alxdgr8

Biggest OEM MAF that I've seen is the Lightning MAF which is 90mm (IIRC that's what toddk911 runs). The 90mm Lightning is good to 850cfm

marcoturbo

What kind of air filter do you consider fitting ?

With a 4" MAF, the Honda Prelude cone air filter doesn't fit

pete95zhn

Put the MAF to the pressure side, that way you can run 4" piping to the compressor inlet. BTDT.

TurboTommy

I'd be interested in a 3.5 inch MAF as well.

Thom

Marc, modifying this cone filter should work as the base circle has a diameter of 133mm which is more than 4" (~100mm).

Pete, I remember a picture of your set up showing the MAF behind the IC, but I would be concerned with throwing oil on the sensor if fitting the MAF anywhere after the turbo - What could you observe on this matter?

John, what is your opinion on fitting the MAF after the turbo?

TIA.

alxdgr8

I've run blow through MAF setups on other cars before with no problems. A good catch can should take care of any oil issues so long as your turbo is in good shape. One thing to pay attention to in a blow-thru setup is you'll most likely want to use a metal frame MAF, not a plastic frame like some due to it having to meter "hot" air.

marcoturbo

Thom, the outter diameter is 133 mm, not the inner where the MAF pipe connects to the filter.

Check it http://www.napafilters.com/filterloo....asp?Part=6277

Thom

pete95zhn

+1, I used Saikou Michi catch can. With new turbo there were no oil residue in IC piping. I also had the MAF after the IC, so air temp was in control.

fast951

The MAF you have now can be used as a Blow Through (after the turbo). As you mentioned, oil can contaminate the sensor, so a good catch can and frequent MAF cleaning are good measures.

marcoturbo

Thom, there's no escape... You must run a MAF pipe and install an oil catch can ( I know where a brand new Saikou Michi lies around...)