RB26 APexi PFC Compatibility With rb25

[opticnerv]

Will the RB 26 PFC work with an rb25 ? If not what kind of modifications will I have to make ? I'm ordering a chasebay harness I would hate to hack it up just to save a couple bucks ( I found that rb26 PFC's go for less ).

[Cjmartz2k]

You will loose VCT (unless you wire up an RPM window switch separately or something), you will have to add a couple of sensors IIRC, and you will have to swap around a few pins where the harness plugs in to the ecu.

I don't remember exactly what pins need switching and I don't remember exactly what sensor(s) you need. It's been too long. I just compared the two wiring diagrams and figured it out. I would suggest you start there, and if you have any specific questions, we can probably help.

[gawdzilla]

intake air temp sensor is one that the 26 has and the 25 doesn't.
26 also doubles up on mafs and o2 sensors. mafs might be tricky but o2 sensors can be wired together. probably best to start with a 26 harness i'd say.

[Krazykouki]

Unless it's a D-Jetro I would not mess with it. My Rb25 was running on an RB26 ecu, ran like s*** without the IAT sensor and the MAF system never wanted to work right.

[Cjmartz2k]

Yeah, those are a couple of the sensors. I swapped in a D-jetro and you still have to play with it to make it work. I want to say there was something with a idle switch or something like that?

[StricNyne]

its pretty simple, i ran a 26 pfc on my 25, like cj said u need to use a window switch or rpm activated switch for vct, and thats it , you might need to adjust voltage for maf a bit though. the air temp sensor the 26 has is just used for retarding timing, but if it dosent read iirc it leaves timing alone, google paulr33 pfc faq and it has good info within

[StricNyne]

its pretty simple, i ran a 26 pfc on my 25, like cj said u need to use a window switch or rpm activated switch for vct, and thats it , you might need to adjust voltage for maf a bit though. the air temp sensor the 26 has is just used for retarding timing, but if it dosent read iirc it leaves timing alone, google paulr33 pfc faq and it has good info within

[opticnerv]

Thanks for all the replies ! According to Paulr33's FAQ you pretty much just have to run the 02 Sensors and MAF sensors in parallel because the rb26 has two of each. Does VTC have a big effect on HP ?

[Cjmartz2k]

I think it actaully retards the cam in the lower RPMs when active, so not having it won't effect peak power, but it will lower low/mid range power a bit. Are you running stock cams?