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I don't now. I haven't done it.

I have participated in putting an R34 Neo loom into R32 before. There are a lot of things that are different. Complete devices that are different, plugs that are different, circuits that are run differently. You basically have to lay the two looms out and the two wiring diagrams out next to each other and make the changes required.

I do not know of a recipe book for what you want.

Well, it's not true. The are differences between S1 and S2 R33 RB25DET looms, let alone between R33 and R32.

The differences that you need to take into account are where the engine loom butts up against the body loom. Things like the alternator wiring, main power supplies from the fuse box, etc. Even the details around exactly how the ECCS relay and fuel pump wiring at the ECU location are a little different.

Well....seeing as the R33 RB25 ECU is a piece of shit with more aggressive R&R behaviours than the R32's ECU, and you can Nistune an R32 ECU and can't Nistune an R33 ECU....I can't see why anyone would even want to run a 20 with a 25 ECU.

And then, once you get past that, the stock maps in the 25 ECU won't be well matched to what the RB20 wants, so it will not run nicely. You would be 1000% better off running it on a homebuilt programmable ECU.

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I'm not entirely certain what your end goal is but if it's just to pop in an RB25 into an R32 using stock components, R32 and R33 loom both use the same ecu connector. Use the R32 loom and R33 ECU. You will have some minor changes to make to the ecu pinout though. 

  • Like 1
1 hour ago, GTSBoy said:

Well....seeing as the R33 RB25 ECU is a piece of shit with more aggressive R&R behaviours than the R32's ECU, and you can Nistune an R32 ECU and can't Nistune an R33 ECU....I can't see why anyone would even want to run a 20 with a 25 ECU.

And then, once you get past that, the stock maps in the 25 ECU won't be well matched to what the RB20 wants, so it will not run nicely. You would be 1000% better off running it on a homebuilt programmable ECU.

Got it but i have microtech lt16c was on 33-25 with harness patch  and plug 

 

thats the reason i was asking. That ecu will work or i have to do some pinout modifications on the patch to work on rb20-?

IMG_1142.jpeg

5 minutes ago, Ak brar said:

Got it but i have microtech lt16c was on 33-25 with harness patch  and plug 

 

thats the reason i was asking. That ecu will work or i have to do some pinout modifications on the patch to work on rb20-?

IMG_1142.jpeg

That ecu will work. Just swap around the IO you need in the ecu. Look up Rb25/R32 conversion DIY's and they document which pins or I/O need swapped in the ecu. 

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