Dual Afm On Singelturbo Rb25det

[h2k]

Anybody know how to hook up a dual AFM setup on a RB25DET ? Right now Im running a single Q45 3,5" AFM but I'm going to max it out with the new turbo so I was thinking about making a Y-pipe for the intake and use dual Q45 AFM's.

Im running powerFC, can I just paralell couple the AFM signal wire or will this not work? The GTR with dual afm...does it have 2 signal wires on the ecu?

[paulr33]

you will need to either change to GTR PFC or you can use apexi SAFC II to parrallel up the AFM signals

i believe the unit lets you choose which mode to interpolate the afm signal, avg, max, double, half etc

just dont do any correction on the maps and use it as an AFM adapter/splitter

[h2k]

kinda expensive to buy a SAFC2 just to act as a signal Y-connector when I've allready have a PowerFC

[R31Nismoid]

What setup are we talking about?

[Sydneykid]

Anybody know how to hook up a dual AFM setup on a RB25DET ? Right now Im running a single Q45 3,5" AFM but I'm going to max it out with the new turbo so I was thinking about making a Y-pipe for the intake and use dual Q45 AFM's.

Im running powerFC, can I just paralell couple the AFM signal wire or will this not work?

Why have 2 AFM's? You don't need them, you can tune off one. So just use a "Y" inlet, the Q45 AFM on one and no AFM on the other.

The GTR with dual afm...does it have 2 signal wires on the ecu?

Yes

cheers

[h2k]

What setup are we talking about?

Bottom end:

RB25DET bored 2580CC

Wiseco forged oversize pistons

Eagle forged conrods

Calico Racing bearings

Top decked

Head:

Shaved head

Ported and polished

Valve and valveseat cut

Tomei poncams 254

Cometic multilayer steel gasket 1.6mm

Other:

OBX T4 Pulse split manifold

OBX 50mm wastegate

Garrett GT4088R pulse split turbo

JUN-style intake plenum (portmatched)

Q45 90mm throttle body

Q45 90mm MAF sensor

Nismo\JECS 800cc injectors

Nismo Adjustable fuel pressure regulator

Apexi PowerFC

Apexi pod filter

Apexi AVC-R boostcontroller

HKS SSQV bov

Innovate Motorsports LC-1 with XD-16 Wide Band Kit

BOSCH 040 fuel pump

Oil catch tank

Oil cooler and filter relocation

OS Giken twinplate racing clutch

HICAS removal bar

Hybrid FMIC

3" straight exaust with 5" jap exaust tip

[h2k]

Why have 2 AFM's? You don't need them, you can tune off one. So just use a "Y" inlet, the Q45 AFM on one and no AFM on the other.

Yes

cheers

Because I maxed out the q45 afm I have already at 1.0bar, and I'm currently running 1.5 bars. And I want to go even higher =)

[clip14]

upgrade to map sensor?

[dano4127]

upgrade to map sensor?

+1

but wouldnt have thought the Q45 would be maxed out already

[Gts-t]

Because I maxed out the q45 afm I have already at 1.0bar, and I'm currently running 1.5 bars. And I want to go even higher =)

pretty sure SK is saying u dont need two afms. and that if u set it up the way he said, then a whole lot of air would by pass the afm, im guessing lowering the volts its reading and allowing u some tuning room again.

i could be wrong tho

[Mr Jollwah]

If running a dummy AFM, I think you'll need to change the K value as the working AFM will only measure half the air.

[abu]

upgrade to map sensor?

I agree with that also.

Go to a MAP. I think most standard internal MAP sensors are roughly 25psi (Wolf/Microtech), then you can upgrade to an external MAP which goes to about 35psi roughly.

Abu

Edited September 10, 2007 by abu

[R31Nismoid]

Because I maxed out the q45 afm I have already at 1.0bar, and I'm currently running 1.5 bars. And I want to go even higher =)

Do you get what he meant though?

Doesnt sound like it as it would solve your problem, and not cost much

[_Scotty_]

Because I maxed out the q45 afm I have already at 1.0bar, and I'm currently running 1.5 bars. And I want to go even higher =)

Not that I think much of Autospeed these days, but this might explain what SK means about using just one AFM...

http://autospeed.com.au/cms/A_2424/article.html

[2rismo]

Autronic will fix this problem and you will almost pay for it entirely by selling your pfc and afm's.

Problem solved.

[h2k]

Changing to map sensor is very expensive since I need to change my pfc unit. And since I live in Norway it is not very eazy to sell used skylineparts locally =)

I was hoping there was a easy and cheap fix with paralell wiring for dual afm's =)

[h2k]

Do you get what he meant though?

Doesnt sound like it as it would solve your problem, and not cost much

At first I didnt understand it, but after reading it a couple of times I think I get it =) only running on MAF, and making a tune to compensate for the "false" air that runs trough the other funnel. I get it...interesting suggestion.

[BAMR33]

*makes note to self * 'sell z32 afm and replace with stock afm next tune'

[Guilt-Toy]

I need to do something like this as well. I need to run a bypass valve and re-tune my car.

I want to run 30psi and I cant because my AFM is making out at around 24psi.

I am going to either modify my AFM and remove it from the plastic pipe its in and then put it into a 4" pipe OR i will run a bypass....

[Mr Jollwah]

Have been looking around some of the z32 forums, apparently u can run one working/one dummy maf sensor and halve the k value in the std ecu, sounds to simple. might be a little more complicated than this.

I was thinking that wiring the two in parallel to average the voltage, then halve the K value would be better.

Not sure how this equates with u PFC users out there.