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Hey all

I have a r31 drift car... i changed the rb30 for a rb20det. wired it all up using standard 20 computer etc

now the 20 has gone to heaven, i have an rb25.

ive got it all in, but what do i need to do re wiring? i have the stock 20 loom there and stock 20 computer.

can someone send me to a how to that actually works?

any tips?

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Somewhat depends on whether you have an S1 or S2 RB25.  Do you have Nistune in the ECU?  Otherwise, do you have a plan for making the VCT work?

The main points are:

  • Dealing with pin changes on the AFM and CAS.
  • Differences in connectors for things like the alternator (and AC compressor, if that matters to you, which it probably doesn't).
  • Ignitor pack/coils, which is where the S1/S@ thing comes in.

Probably best you give a little more info on the type of 25.  I'm not saying I've got the answers, but others might be better able to point you to the howto you want.

 

So you will need to Nistune the ECU anyway, because you need to be able to tune it to make it run the 25 properly anyway.  That can allow you to use the blinky LED of the ECU as another output to run the VCT.  Look at Nistune's support docs for how this is done.  If you don't do it that way, you will need to use an EBoost or something else with a window switch to allow you to switch the VCT on and off at the required revs.

The coil wiring should be all the same.  You just need to google up the pinout differences on the CAS and AFM, for the most part.

Oh, and injectors.  I don't know for sure, but it's probably the case that you will need different plugs.  Probably justified in binning the sidefeeds and using new EV14 based injectors, that you can buy with loom adapters to suit the RB20 plugs. (and a new fuel rail and the spacers and stuff you need to mount it all.)

7 hours ago, Adz2332 said:

ive got it all in, but what do i need to do re wiring? i have the stock 20 loom there and stock 20 computer.

can someone send me to a how to that actually works?

Hey mate I have the R33 engine manual on PDF has all the RB20 / RB25 / RB26  ecu pinouts and the component wiring diagrams ( no colour wiring unfortunately ) if you want it I can pm it to you.

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