RB26 airflow meter upgrade Rb20 or 25??

[[[d a n n y]]]

Heya people i did a search but i cant really seem to find any information about the RB20/25 into RB26 airflow meter upgrade

what gains are there?

can the Apexi Power FC can tune it with N1 turbos?

any help would be appreciated

[BoOsTeD_RB26]

I was told they are the same (RB20DET from the R32 and the Rb25DET afm that is). They have the same part number.

pnblight had them on his car and cracked 500hp at the tyres with them so they'd be fine.

[paulr33]

rb20 and rb25 afm are same size and same calibration.

Rule of thumb for Air Flow meters RWKW & Engine BHP

------ ---- OD ---- RWKW ---- RWKW ---- BHP ------ BHP

No of AFM's ---- ------- 1 -------- 2 -------- 1 -------- 2

RB26 ------ 65 ------ 149 ------ 299 ------ 271 ------ 474

RB20/25 --- 80 ------ 226 ------ 453 ------ 376 ------ 683

Z32 ------- 80 ------ 255 ------ 511 ------ 415 ------ 763

Q45 ------- 90 ------ 302 ------ 605 ------ 479 ------ 890

[[[d a n n y]]]

so it'll be a good upgrade for my car would it

[[[d a n n y]]]

1 more questions does would i need to modifty the plug to make it suit?

[pnblight]

OK the rb20/25afms are a good upgrade for the gtr rb26 with a pfc as the afms will plug straight into existing harness and can be selected from a menu in the setting of the pfc ,the only thing is, it normally requires some customising of the pipe work to the turbos from the afms (the same as would be required for the z32) and the best advantage over nismo units is price and less restriction to flow (80mm over 62mm) PLUS i remend de-screening them as the mash covers about 33% of the cross sectional area of the afm and the turbulence would be significant (just make sure you run good filters).

PS. if you are aiming over 540rwhp i would go the Z32 as my rb20/25 were reading 5.03volts(5.13 is max out) at around the 529rwhp mark, my z32 now read in the low 4volt range for the same hp.

cheers

[[[d a n n y]]]

more info on the customing piping plz?

what do u mean aftermarket piping???

[JH32]

do you take the mesh off the front AND the back ?

[BoOsTeD_RB26]

Aftermarket piping is beneficial however it isnt required so to speak. If you dont have the funds they do sqeeze into the factory rubber piping. I did this with mine!

Piping is expensive. The Greddy suction kit is $1,100 odd delivered from nengun!

I have removed the rear screen on my afms. Not the front as I've heard conflicting rumours.

[RedDrifter]

rb20 and rb25 afm are same size and same calibration.

Rule of thumb for Air Flow meters RWKW & Engine BHP

------ ---- OD ---- RWKW ---- RWKW ---- BHP ------ BHP

No of AFM's ---- ------- 1 -------- 2 -------- 1 -------- 2

RB26 ------ 65 ------ 149 ------ 299 ------ 271 ------ 474

RB20/25 --- 80 ------ 226 ------ 453 ------ 376 ------ 683

Z32 ------- 80 ------ 255 ------ 511 ------ 415 ------ 763

Q45 ------- 90 ------ 302 ------ 605 ------ 479 ------ 890

How accurate are these figues?

Need to get a resonable guess to get me started as i am soon upgradeing my RB20 afm to z32 using the stock ecu.

[7heavn]

rb20/25 afm's are the same . I have rb25 afm's on my GTR if you have custom pods then they will probably not bolt up to the 80mm afm's like I found with my blitz pods. I just bought two gts-t pod adapters and mounted new filters . The rubber turbo intake pipes just squeeze over the back of the 80mm afm's help to heat them up they slip on easier. Have a look in my gallery have a pic of the my engine bay with rb25 afm's .

[williamsf1]

so does anyone have any other info on the "de-screening" of the RB20 AFM?

[Mik]

The other option is NISMO AFMs and use the OEM airbox. Bolt and plug straight in, easy to set up with a PFC.

[7heavn]

wouldn't bother with de-screening unless your looking at making serioues power (something close to 500rwhp ) . Like Mik said nismo's are another idea and there new as well unlike used rb20/25 and z32's .

[[[d a n n y]]]

hm..350KW atw ???is that high enuff to get rid of em?

anywayz need new adaptors for the pod

[pnblight]

in my opinion if your looking to replace the std afms it means you are looking over 400rwhp as i believe that about where the std afms start to run out of head room, and that be so you are starting to look at serious power levels.

So concider this while people go full on with big exhausts and plenums and coolers to etc etc why would you run a resistive intake where the air has to be drone in (not pumped etc)

so the choice of good filters and intake piping and large not resistive afms are very important as this is the first link in the chain

(as what air you are trying to pump through the rest of the system must pass through here first and must do so under no pressure only by the vacuvm of the turbo intake)

eg why put a ~2"x2(ID)grilled afm on the intake and a twin 3" exhaust or 4"intercooler

the grill takes up about 33% of the cross sectional area of the afm and serve no purpose but to add resistion to air flow(i believe the only reason the grills are there is to stop objects touch the afm elements).So if you run good filters and dont go putting tools or fingers into them the grill is redundant.

my 2c

[GTR-Ben]

I made a post a while ago about running the AFM inline as well as increasing the ID of the pipe the AFM is installed into to allow more power before maxing out etc.. I got no responce..

I will be trying this on my own setup though. The AFM probe is simply O-ringed into the pipe. I think if I run a single GTS-T 80mm AFM inside a 4" pipe, this will have the same flow as 2 x 3" pipes, saving a lot of space

e.g a 80mm GTS-T afm in a 4" pipe should in theory allow 453rwkw. I'm not sure how this would effect the resolution however. I was hoping an expert could shed some light..

Seems like a lot easier and cheaper way to do things if it works. I know of a few cars running AFM's inline on the pressure side of the piping. Normally after the Intercooler.

[[[d a n n y]]]

hm..intresting.