Jump to content
SAU Community

Recommended Posts

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?

Link to comment
https://www.sau.com.au/forums/topic/177223-dual-afm-on-singelturbo-rb25det/
Share on other sites

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

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

:D cheers :D

  • 1 month later...
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

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 :spank:

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 =)

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 :(

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 by abu
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

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

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 =)

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.

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....

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.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Even more fun, leave all the ADAS stuff plugged in, but in different locations, hopefully avoid any codes!   And honestly, all these new cars with their weird electronics. Pull all the electronics out Duncan, and just shove an aftermarket ECU and if needed a trans controller in, along with a PDM. Make it run basic but race car styled!
    • To follow up a question from earlier too since I had the front bar off again (fking!) This is what is between the bumper and the drivers side wheel And this is the navigator side, only one thing but its a biggy! So basically....no putting coolers in the wheel arches without a lot of moving other stuff. Assuming I move to properly race prepping this car I'll take that job on and see how the computers respond to removing a whole bunch of ADAS modules
    • So I prepped the car for another track day on Wednesday (will be interesting to see coolant temps post flushing out and the larger reservoir, with a forecast of 3-14 being 20o cooler than last time I took it out). Couple of things to mention; since I am just driving the car and not taking a support vehicle, I took the rear seats out and just loaded the back up Team Trackday style. Look at all that space! To cover off removing the rear seat....it is weird (note the hybrid is probably different because it wouldn't have folding rear seats) Basically, you remove the lower seat base, very similar to a r series but it is a clip that pulls forward to release the base rather than it being bolted down. Easy Then, you need to remove the side section of the rear seat on each side. There is a 14mm head nut at the bottom of the side piece, the it slides upwards off a hook at the top to release; you also need to unhook the seatbelt from the loop at the top. Then the centre piece is weird. You need to release/fold the seats forward with the tab in the boot on each side From there, there are 2,x12mm headed bolts holding the rear of each seat to the folding bracket, under the trim between the rear seat and the boot (4x christmas tree clips there, they suck). The seat is out but you can see where the bolts attach to the bracket
    • As discussed in the previous post, the bushes in the 110 needed replacing. I took this opportunity to replace the castor bushes, the front lower control arm, lower the car and get the alignment dialled in with new tyres. I took it down to Alignment Motorsports on the GC to get this work done and also get more out of the Shockworks as I felt like I wasn't getting the full use out of them.  To cut a very long story short, it ended up being the case the passenger side castor arm wouldn't accept the brand new bush as the sleeve had worn badly enough to the point you could push the new bush in by hand and completely through. Trying a pair of TRD bushes didn't fix the issue either (I had originally gone with Hardrace bushes). We needed to urgently source another castor arm, and thankfully this was sourced and the guys at the shop worked on my car until 7pm on a Saturday to get everything done. The car rides a lot nicer now with the suspension dialled in properly. Lowered the car a little as well to suit the lower profile front tyres, and just bring the car down generally. Eternally thankful for the guys down at the shop to get the car sorted, we both pulled big favours from our contacts to get it done on the Saturday.  Also plugged in the new Stedi foglights into the S15, and even from a quick test in the garage I'm keen to see how they look out on the road. I had some concerns about the length of the LED body and whether it'd fit in the foglight housing but it's fine.  I've got a small window coming up next month where I'll likely get a little paint work done on the 110 to remove the rear wing, add a boot wing and roof wing, get the side skirt fixed up and colour match the little panel on the tail lights so that I can install some badges that I've kept in storage. I'm also tempted to put in a new pair of headlights on the 110.  Until then, here's some more pictures from Easter this year. 
    • I would put a fuel pressure gauge between the filter and the fuel rail, see if it's maintaining good fuel pressure at idle going up to the point when it stalls. Do you see any strange behavior in commanded fuel leading up to the point when it stalls? You might have to start going through the service manual and doing a long list of sensor tests if it's not the fuel system for whatever reason.
×
×
  • Create New...