R32 GTR with RB25 AFMs

[itbmils]

All

I've just done a full engine rebuild on my R32 GTR (almost run in now) and I'm planning on taking it to the next level. I have the following bits ready to install

PCF + HC

Tomei Adj CAM gears in/out

HKS 550cc injectors

I've just picked up a pair of RB25 AFMs (herd they were a cheap upgrade) and I was wondering if ....

the PFC has a setting for these

can I swap them for the std AFMs before fitting the PFC

Anyone know where I can get a piping kit for these to suit my GTR - I have pods (Ms I think) can I keep those and just swap the pipe between the pod filter and the AFM

will I also need to swap out the hose between the AFM and the turbo (flexible ?)

[itbmils]

Anyone

I thought they were reasonable questions !!!

[scottgtr]

Yes the power fc has a setting for the rb25 afm's. i highly doubt that you would be able to buy a bolt on intake kit to suit though, you will probably have to get something made up and there is no reason why you couldnt use your current pods but due to the larger diameter of the afm's they probably wouldnt be big enough. As for fitting them before the power fc, i dont think it would be overly wise due to the standard computer not being tuned to suit, i personally would wait untill i got the ecu in. Ive heard that the rb25 afm isnt all that good on a rb26 due to the fact that they cant hanlde as much air up in the higher revs and the calibration is slightly different. I personally would (and have) opt for a pair of z32 afm's. I hope that helps you out a little.

[paulr33]

I dont believe the stock ecu will support them. If you have the new powerfc, then option 4 under airflow setting lets you use twin rb25 afms. Im not sure what the value is for the older powerfc (as in the one that came seperate with the hand controller).

The newer powerfc supports:

Option 1: BNR33 Normal

Option 2: BNR32 Normal

Option 3: Power Intake

Option 4: 80(squiggle O) RB25 Air-F (twin rb25 afms)

Option 5: 80(squiggle O) VG30 Air-F (twin z32s afms)

[paulr33]

[itbmils]

good work guys

I figured I need to get some made up - that's OK

Hmmm - not a good upgrade - anyone confirm this - should I get z32s instead ?

[DAN00H]

do a search on what the RB20/25, RB26 and Z32 AFM's flow. SK was kind enough to provide a list of the power available in single and twin configurations.

From my understainding, the RB25's are fine if you are not going over 450RWKW.

[paulr33]

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

[itbmils]

very good work - RB25's will be fine for me - target is only 280-300rwkw

[7heavn]

rb25 afm's on mine with the PFC and 2530's . Car did run with rb25 afm's straight up but not well and was tilt trayed to the tuner . If your only looking for 300rwkw then they will have plently of headroom . pnblight on these forums only maxed his out at close to 500rwhp on his 33 GTR .

[williamsf1]

anyone in sydney know where to buy piping to adapt the HKS pods to the RB25 AFMS?

[Sydneykid]

anyone in sydney know where to buy piping to adapt the HKS pods to the RB25 AFMS?

My solution has been to sell the GTR PODs and buy 2 X GTST pods.

[Ants]

very good work - RB25's will be fine for me - target is only 280-300rwkw

Mate, I managed to get 297rwkw with my standard GT-R a/f meters, I have RB25 a/f as well but could not put them on yet because of the same reason you do i.e. piping and pods do not fit.

[Beer Baron]

you can use a Z32 adapter kit as RB25s AFMs are 80mm just like the Z32s

Apexi and HKS both make a GTR kit to suit 80mm AFMs.

[blk180]

what are nizmo afm rated at

[Ants]

Apparently 775ps (at engine) is the limit of the nismo A/f meters.

[LISTEN 180SX]

what are nizmo afm rated at

i didnt know that nismo had a specific AFM. what car do they come on?

[Ants]

They do not come off a standard production car as such, the a/f meter can be purchased as an after market item just like the mines a/f meter.

[Mik]

Apparently 775ps (at engine) is the limit of the nismo A/f meters.

And the real beauty of them is that you can run the OEM airbox

[williamsf1]

I think SK might be right......

I may have to sell the GTR pods and get some to fit the RB25..... any ideas? here in sydney? price?