Using An Rb26dett Power Fc On An Rb20det

[Beer Baron]

i think the best idea for an RB20 PFC (if it works) is using a 32 GTR PFC, with a set of 440cc GTR injectors and the resistor pack. all up it would still be around the same or cheaper than an AP engineering PFC and you have the advantage of 440cc injectors

[MattSR]

Or enough left over for a datalogit

[kwazza11]

so can you select a single AFM option on the rb26 power fc? ie if you wanted to go with a single Q45 AFM on your rb26?

if so makes it alot easier to get a rb20 up and running, use a q45 afm, gtr injectors, gtr PFC, ends up being dirt cheap in comparison.

also anyone able to spin some light on whether the tacho outputs are the same on rb20/rb26?

[paulr33]

no on the powerfc for rb26 when you choose VH41 90o it means twin airflow meters of that type. basically you run the wiring for both airflow meter signals to the same airflow meter., so the pfc can see two q45's both retuning the same voltage, and you have one physical airflow meter

[kwazza11]

ok sounds easy but wouldnt the ecu then think your using twice the airflow than you actually are?

[MattSR]

Yes, thats why you need to adjust the airflow meter voltage curve inside the PFC to suit.

[SirRacer]

so just to confirm what everyone has said

you can use a gtr32 power fc on an rb20det with not to much hassle by basically wiring the afm's in parallel so the computer only picks up one signal and likewise with the oxygen sensors

are there any other plugs or things i would need to be aware of?

[SirRacer]

Can anyone elaborate on this as otherwise it could be a costly exercise buying a gtr power fc then finding it doesnt work. What problems may i have?

Car is an a31 cefiro rb20e originally running rb20de loom(same as 20det) and rb30 r32 25 head. Im also going to be running sard 700's (i got them dirt cheap) with a resistor pack.

[NathR32]

Alright guys I'm a little confused here as there is so much information that I can't possibly process

I have an R32 GTS-t RB20DET. Short of buying an AP Engineering PFC, which out of the two PFC's described in this thread would be a better option: R33 RB25 S1 PFC, or an R32 GTR PFC.

From what I can understand:

The main difference between the R32 AP Engineering, R33 RB25 and R32 GTR PowerFC's is the amount of AFM's(GTR issue) and the size of the injectors and lack of resistor?

I plan to change my injectors to something bigger anyway, but plan on using one AFM either utilising the stock RB20 AFM or upgrading to a Z32 one.

Which out of the R33 GTS-T and the R32 GTR Power FC's is the easiest option to suit an RB20DET? ie less modifications to suit. Then with that best option, what things will I need to change (injectors, resistor, changing the pinouts etc)?

Any help would be greatly appreciated, if it's too much work or not going to work then I guess I'll have to fork out for the AP Engineering one instead :

Cheers guys,

Nath

[kwazza11]

Sounds to me the cheapest way around it would be to use the GTR PFC, gtr injectors and a Z32/Q45 AFM. get all that for the price of the AP Power FC.

so with adjusting the AFM voltage to suit one AFM i take it you just go to the appropriate screen on the commander (PIM volt?) and change it from 100% to 50% right? can the same be done with the exhaust sensor? and do you need to run an rb26 exhaust sensor or are they the same accross the rb range?

also can anyone say whether the tacho output on the rb26 ECU is the same as the rb20det? or will the tacho be out aswell?

[NathR32]

Thanks for the bit of info kwazza, would be good to find out about the few questions you have.

I was planning on getting bigger injectors and probably a Z32 as well.

If anyone else can help, that would be awesome.

Nath

[carl h]

your best bet is to go with a rb25pfc, unless you are trying to run dejetro or something i dont see why you would go for the rb26 one.

swap 2 wires on the wire loom and away you go with a rb25pfc, bit more on the rb26 one to make it fit.

fyi rb20 maf = rb25 maf, so with the 25pfc you can keep your stock mafo around for a bit...

[NathR32]

So with the RB25 one, you change the injector impedence settings, and modify a few wires? I'm planning on going with bigger injectors, would I need a resistor? And I assume you'd go for a series 1 one, as someone said series 2 would be a little different.

[Cubes]

So with the RB25 one, you change the injector impedence settings, and modify a few wires? I'm planning on going with bigger injectors, would I need a resistor? And I assume you'd go for a series 1 one, as someone said series 2 would be a little different.

RB25 and RB20 injector impedence are high.

GTR is low, they run a resistor pack so the ecu's are essentially a high impedence.

[carl h]

there is only one pfc for the rb25 and it works on the s1 or s2 motors...

i think i stated this before but when using a rb25pfc you MUST upgrade injectors because the pfc expects 370cc injectors stock while the rb20 has 270's, not a hard thing to rectify and should be done anyways.

[N I B]

Tacho output is the same.

[Cubes]

there is only one pfc for the rb25 and it works on the s1 or s2 motors...

i think i stated this before but when using a rb25pfc you MUST upgrade injectors because the pfc expects 370cc injectors stock while the rb20 has 270's, not a hard thing to rectify and should be done anyways.

Even then its not difficult to rectify, simply dial in 142% in the injector correction.

old injectors / new injectors * 100 = injector correction

[NathR32]

Thanks guys. Looks like I'll be able to get an RB25 PFC and bigger injectors for the same price as an AP Engineering one

Nath

Edited April 9, 2006 by NathR32

[SirRacer]

Thanks guys. Looks like I'll be able to get an RB25 PFC and bigger injectors for the same price as an AP Engineering one

Nath

keep us posted on how this goes as im also interested in adapting some kind of power fc to my car

[grigor]

After all that, have I got it right????

Rb20det injectors are top feed, 270cc, 13 ohms.

Rb25det injectors are side feed, 370cc, 13 ohms.

Rb26dett injectors are top feed, 444cc, 3-4 ohms.

Rb20det ecu has pin 112 as inj 4, pin 114 as inj 6.

Rb25det ecu has pin 112 as inj 6, pin 114 as inj 4.

Rb26dett ecu has pin 112 as inj 6, pin 114 as inj 4.

Pin 7 is tacho signal on all ecu's.

The extra AFM on the Rb26 uses empty pins in the Rb20 and 25 plugs.

The extra oxygen sensor on the Rb26 uses empty pins in the Rb20 and 25 plugs.

Pin 25 is boost control valve on the Rb25 and Rb26, and empty in the Rb20.

Pin 113 is VVT on the Rb25 and empty on the Rb20 and 26.

So for an easy Rb20det fix, I'd buy an Rb25det PFc, swap wires to pins 112 and 114, alter the duty cycle on the injectors and start tuning???

For more power in the future, I'd buy the Rb26dett PFc, swap wires to pins 112 and 114, buy some 444cc GTR injectors and their resistor pack, and as for the AFM's and oxygen sensors, I'd have to PM SK......