Setting the MAF to the power FC

[boucherie]

Ive gone to the blow through setup on my car (which is working fine with no ill effects thus far!)

when i fitted the new maf (75mm diam) the car still runs fine etc but it wont boost above 0.4bar and go over 3-3.5k rpm. this has been ok for going to work but i fitted the stock maf just to see if maybe the maf was iffy?
The old maf works fine and boost and revs are as expected, which leads me to think for the stock setup should i have adjusted the %value for the new maf so that it was the same as stock?

on this basis can someone double check my calculations so that i can then try the new maf again

stock maf:
area = pie x radius squared = 3.141 x (2.5x2.5) = 19.63cm2

new maf
3.141x (3.75x3.75) = 44.18cm2

to get the %value divide old maf figure by new maf figure = 19.63/44.18 = 0.444 or 44.4%

on this theory if i readjusted the new maf figure to 44.5% should this give the same percentage of air flow across the voltage scale?

failing that il leave the stock one in place and wait till the mapping!!

cheers people

 

[AJ4]

what MAF is it ? Z32 or something else ?

 

[boucherie]

i think its one of the 80mm maxima ones, which to my knowledge are the same as the z32's as in the wirings the same, theres no difference in internals etc

 

[AJ4]

Isnt the maxima one a q45 ?, 90mm ( outside diameter ). Anyway, you can just select z32 or q45 maf in the pfc directly and not have to worry about it ?

I think the VG30 is the Z32 and the VH40 is the Q45.

 

[boucherie]

cheers ross, i was going to PM you about this little query but i thought it better to open it up to the forum. im pretty sure its 80mm external diameter and when i selected it to z32 it ran for a bit then went a bit lumpy so maybe i need to select it to the next one up?

il have a play and see what happens, but i can confirm that blow through is the way to go after i blew a hose off (loose clamp!) on the test run and still managed to drive 3miles home with no ill effect!!

 

[cmng]

it not the MAF size concern
it the MAF model issue
it the MAF resolution that count

SR16VE MAF is similiar size with Z32 MAF but only can read out to 330hp only

 

[AJ4]

dont forget that changing the maf you will have to re-scale the load map or you'll run off the edge when you put your foot down...