Hi guy's/girls just a quick question, how big is a big maf? im guessing 4 inch? Reason being i need to buy a samcos hose and air filter to suit befor i go see flea. Cheers

Nick

pretty sure it's 4 inch pal

Barely fits down in the 'bay

Last time I spoke to flea he said it was 3.5".

I need exact sizes hopefully someone else who has one could confirm. I would get in contact with Flea but as we all know hes on holiday.

3.5"

Yes, it's 3.5"

As for the hoses, make sure to order the 89mm hoses from the big MAF side.

cheers guys

If the internal area of the MAF is too small (taken up by the sensor element) for you, you can always convert to MAP, or even better, run a twin MAF. I've used APEXI's SAFC II to do so, it's got a function that can add up the signals from 2 MAF unit. The only issue, like mentioned is the "bay area"

Cheers,

David

i cant find any info on this big maf? any links to pics or info

When flea does a stage 5 remap the MAF sensor is removed and put into a new "custom" housing which is 3.5" instead of 3" that gives more head room for high BHP on OE management. No need for twin MAF or MAP.

@ DavidL
In fact I do not understand your point of twin MAF. If you was to use this idea what is the point in having a second sensor? The first sensor will be equally split with a Y piece so the airflow measured by one sensor will be exactly the same as the other sensor so you only need one sensor to measure and just double the reading. This method would be the same as adding a MAF to a 4.2" housing which is far too much. Personally 3.5" Big MAF works and would be my personal method for the OE management.

but if thats the case then what if you have a sip fitted? mines 3" i think so making a 3.5" maf housing would need a reducer fitted from 3.5 to 3" to the sip then on the other side of the 3.5" maf housing the k&n filter

so im thinking its something like these two

big maf 1

big maf 2

Yes that is exactly what it is just a 3.5” metal tube that can house the sensor nothing special, the specialness is the re-calibration the ECU to work with it. You would need some reducers to step up and down to fit the big MAF that is what Nick was originally asking.

TurboJ is right my sip is 4" so i would need to step down to 3.5 inch i was hoping that the big maf that flea sells was 4" but unfortunatly it isn't so i need to buy reducers to suit.