Thinking of a few mods to do this Spring before going for another remap of my Power FC equipped MY98 WRX. Chiefly, a front mount intercooler and a Z32 MAF. After recent minor porting and polishing of my throttle body and inlet manifold, as well as a new group N Green panel filter and a pretty big silicone inlet pipe to replace the ****ty plastic original, I've had all the signs of significantly more airflow...my injectors used to top out at around 80% duty now they're getting into the high 80's and sometimes the 90's. Max overboost in cold weather used to be around 1.45 over a target of 1.40 and this was pretty rare, now I'm getting 0.15 bar overboost on top of every boost setting, which is only marginally brought back by reducing the solenoid's duty cycle. And there's the direct evidence of the MAF voltages which used to top out at 4970 mV or thereabouts at high revs and full boost. Now I'm seeing almost 5.1 volts under the same sort of load and it's regularly hitting 4.9 volts and above on lower boost settings.

So the question is, are there any downsides to fitting a Nissan Z32 MAF sensor? E.g. idle problems? Obviously I'll be having the Power FC remapped for it when I fit the FMIC anyway. It seems like my 'F' purple/blue label MAF is maxing out or close to it and it's done 120k miles already anyway. Second hand ones are often £100 and brand new ones are £300 from Subaru. So any reason why I shouldn't replace it with a Z32 when the time comes to remap?

 

ive got a 300zx one too...not fitted it yet thought so this will be interesting

 

Ive got a z32 maf fitted. There is a setting in the commander to allow for the z32 maf. It will, as you say need a remap after fitting, but is a direct fit with uk non sti cars

Andy

 

my max boost with std maf was 1.3 bar before it flashed the cell-have had z32 on for three months with no probs-the parts are almost identical-just remember to get the plug with it -now running 740s remapped and 1.45 bar

 

Depending on price you could also go for the STi version 4 MAF...Your local Subaru dealer should be able to supply you one new for around £190...
Requires a quick rewire and a remap...

 

Hey that's not so bad...you got a part number for the sti 4 maf? I'd rather pay £190 for a brand new Subaru part than £100 for a second hand Z32. How much power can the STi 4 MAF support, assuming it's different from mine?

BTW is the Z32 MAF the same diameter pipe as my WRX version 4 MAF?

 

When i bought and orange label maf for my sti 3, the dealer charged me £215 inc vat. Not sure on the Z32 maf but the STI maf is 90mm as opposed to 80mm for the WRX maf.

Banny

 

yes i have bought a z32 maf already and have measure it to be the same size as v3 maf sensor.

 

Well I just saw someone's STi 5 MAF for sale and it's identical to my v4 WRX one, purple/blue F label. Which I know for a fact is £280 + VAT or something outrageous like that from Subaru.

So still sounds like the Z32 may be the best option for more flow.

 

V5 and V4 mafs are completely different design. V5/6 MAF sensors are circa £70 from Subaru.

Andy

 

so is it worth upgradin my MAF from my 93 wrx import?

 

Yes that's a point, I didn't think of that. The v5 and 6 MAFs are just the 'element' rather than the whole tube. So that one I saw can't be from a v5 STi. Did the V4 Sti have a different MAF to the V4 WRX or Turbo 2000?

 

IIRC the 97-98 WRX shares the large bore MAF with the Sti3-4 The UK 97-98 has the smaller bore MAF.
One option is to trim (cut) round the original sensor square section, removing it from the tube and refit it into a larger tube - hey presto a high flow MAF at low cost.

Andy

 

V4 Sti's and 22b's shared the 90mm maf....Part number 22680AA271 orange label with a large capital E...Andy F can probably confirm but these should flow enough for 450 and beyond....

 

We're Top Co.-Exhaust, intake, rod, turbo, impreza, Subaru, suspension, brake pads, Nissan, air ,tuning car, performance car
You could also check out these airflow meter bodies...

 

Yes Martyn, in my experience the Sti3-4 22B maf is good for almost 500bhp although by that power level, most have moved on to a twisted turbo set up and that can cause issues at lower RPM due to the swirl in the intake pipe being picked up as forward flow.

Andy

 

Except the car in question is a wagon and shares the same maf with a UK car.

 

Nobody mentioned wagon !

 

what maf do u use on a twisted turbo setup ?

 

or someone over here might be able to make them so the subaru maf would fit

 

So just to confirm, Z32 MAFs are 80mm, and v4 STi ones are 90mm, but what size are the UK v3/v4 MAFs like I've got (purple F label)? 80mm? Just because I'm mulling over what induction kit to use with it once I have my fmic installed, and need to know whether a kit to fit my normal MAF will also be a straight swap onto a Z32 MAF as well. Or whether I need one specifically for the Z32.

 

i was able to compare the z32 maf and it identical size to v3/22b

 

so it's 90mm then, rather than the 80mm which all Z32 MAFs for sale seem to be???

 

My Z32 maf came in a 80mm tube. It was fitted to a uk my 97 turbo and was a direct physical replacement.

There are some in 90mm tubes, best way is to get one the fits perfectly or you will end up changing other sections of the inlet tract just to match what maf you have aquired.

I got mine from ebay, had to wait a few weks for one to turn up in 80mm

 

Ah that makes sense. So as long as I get an 80mm one I can't go wrong. All the ones on ebay at the moment seem to be 80mm. And the air filter end, is that exactly the same as the Subaru one? So it would fit up to either a standard airbox or a Subaru-specific induction kit with no problems?

 

Yes, its a perfect fit with the oe airbox or any 80mm induction kit

Andy

 

Brilliant that's exactly what I need to know. Better start trawling ebay then: Z32 MAF, £250 FMIC and Apexi Power Intake for a v4 Turbo...oops hang on...

If the WRX/STi version 3-4 MAFs were 90mm then an induction kit to suit the Jap v3/4 won't be right will it? I'll need one for a European spec car with the smaller 80mm 'F' label MAF?

 

Looking to rekindle this thread if possible.
I've just fitted a Z32 (non original JECS / Nissan) to my V4 MY98 WRX and retuned the fueling on my Apexi / LM1. The Apexi has had the airflow set to V30 in settings. The car runs well under load but there is an initial throttle stall on up changes or on hill starts where the engine nearly cuts out before kicking back in. Anyone come across this? Have I got the £50 duff Z32 MAF when I should have got an original or is this something that should be tuned around by a professional rather than me?
Thanks.