Wiring question for Rb25 s13 people

[kwin507]

Okay I have a Rb25 series 2 complete swap with uncut harness

i know i need to extend the o2 and maf

but my main question is do i need to do anything to the harness since i did have a rb20 swap in before ?

reason im asking is because when i bought the motor from Japanese Engine Imports they told me i wouldnt need to mess with the wiring due to my old setup with the rb20.

thanks for any info

[zmannz]

From what I have learned over time about the rb20 vs 25 wiring is maybe you will have a couple different wires going to the dash connector that hangs near the ecu plug, and then either the ignition relay wire or something in the bay where the efi harness plugs to the fuse box. I believe that s1/s2 rb20's and 25's had a combination of possibilities. I know rb20's have a white/purple wire to the ign relay and I think that may be red or something in the 25 loom. Any wiring info you find on the 25 is either gonna be incomplete or not free, so many people are raping kids on the wiring service now that people aren't willing to work together and share info anymore....I am in the process of getting rid of extra crap from my 4 cyl days so I can really dive into the rb25.

[kwin507]

yea that is true. and the wiring service prices are crazy. i mean the only reason i havnt paid that price is because i do wanna do this myself and said i did this but trying to tackle this alone is rough. the easy part was the motor but the wiring is kinda difficult