Rb25 Into R32 - Basic Guide

[r32J3003]

i'll check that.

is there any sample pics of mounts you had fabricated?

[BigC1988]

Plannig to swap a RB25det into my R32 (RB20DE non turbo). I know the basic thing bit I hear the gearbox mounts are different (plannig to use the rb25 box).

Also I dont have any experience with the harness. Has enybody ever done this before?

Help please

[Nismoh]

I'm setting up for my conversion.. if i use a 25det computer, Will i loose

A/C

Wipers

Anything else that isnt directly involved with the engine?

[toddlls]

Great write up, This definitely needs to be stickied in mods section-pls admin pls

[BHDave]

I'm setting up for my conversion.. if i use a 25det computer, Will i loose

A/C

Wipers

Anything else that isnt directly involved with the engine?

Not if it's wired properly.

The wiper section needs to be stripped from the 32 loom and retained, the ac idle step up needs a relay added but the AC itself just needs the trigger wire run from the dash plug to the main power plug in the engine bay.

[Lock_to_lock]

Great Write up!

I im the middle of this conversion and just have a few questions.

Instead of swaping the alternator over to the RB20 one, can i just use the RB25 one? Will it plug up fine with the RB20 loom and earths?

Just making sure. I use the RB20 temp sender and oil pressure sender on the RB25?

What is the Advantage/Difference of using a RB20 computer over a RB25 computer? Which ever one i use i plan to get it remapped.

Depending on which computer i use, will i still need to get the air con re-wired?

And i noticed on the RB25, coming off the actuator there is 2 vaccume hoses, which the RB20 doesnt have. Where do i commect these to?

Any help IS appreciated!

Cheers, Josh

[BHDave]

you can use either alternator, though you may need to drill out the eyelet on the cable to suit the 25 one

you only swap the single wire temp sensor as that's the one for the dash, oil pressure is probably the same but you may as well swap it just in case.

The rb20 computer is easier and cheaper to get remapped but does not support vct. If you were going to use a 20 computer i'd use a 20 loom as well and the 20 sensors, ignitor, afm and replug the injectors, iac etc just to simplify the whole thing. Add in a separate vct controller if you want to retain it and trailer it to your tuner to get remapped and tuned.

Or go the 25 comp and loom which requires redoing the dash plugs and power feeds and a bit of messing about with the wipers ac etc.

With either you would have to add the wiring for the secondary idle control valve as it's not controlled by the ecu in the 25 anyway.

If you aren't looking for a piggy back of a stcok rb25 ecu or an rb25 pfc then i'd stick with the 20 ecu and loom if i were to do it again now. I went with the 25 ecu and loom as i had an intermittent misfire issue and wanted none of the original components to ensure it was resolved. It was also a lot harder to get a decent remap when i did mine so wiring to suit a 25 ecu made sense when the pfc's were readily available and cheaper than 20 ones.

What actuator are you talking about? rb20 and 25 actuators only have 1 signal....

[CeJay]

Great Write up!

I im the middle of this conversion and just have a few questions.

Instead of swaping the alternator over to the RB20 one, can i just use the RB25 one? Will it plug up fine with the RB20 loom and earths?

Just making sure. I use the RB20 temp sender and oil pressure sender on the RB25?

What is the Advantage/Difference of using a RB20 computer over a RB25 computer? Which ever one i use i plan to get it remapped.

Depending on which computer i use, will i still need to get the air con re-wired?

And i noticed on the RB25, coming off the actuator there is 2 vaccume hoses, which the RB20 doesnt have. Where do i commect these to?

Any help IS appreciated!

Cheers, Josh

talk to cef11e if you plan on running the 25 on a remapped 32 ecu, i need to sought out some issues on mine, but it runs well on the 32 ecu.

[Lock_to_lock]

Iv found someone to wire it up, Simon-R32. Hes done a few, and wires it up like a stock install. Cant wait! Going to use the 25 loom and Re-mapped RB20 ecu.

With the RB25 turbo actuator. There is the the line that comes off that actuator, and there was another one which connects to the stock cooler piping.

With the RB20 actuator, the line come off the actuator and returns back onto the turbo.

I wasn't sure where to connect the RB25 lines to. Also i have been told that if i use the RB25 actuator it will only make about 5psi.

Edited August 2, 2008 by Lock_to_lock

[Lock_to_lock]

Just another quick question.

Does it matter which computer i use? What i mean is that which computer i use wont affect the way the car is wired up?

I ask this because im thinking of using the rb25 computer so i can drive it to the tuners, and then get the RB20 remapped to suit.

[BHDave]

there are a couple of different pins. Simon is familiar with whats required as he runs a 32 ecu himself

[Lock_to_lock]

Well there are only a few things left to do before i put the engine in.

How do people do their heater hoses. Do you mix and match the rb20 and 25? I noticed that they are different in size. How have you done yours??

In the RB20 heater hoses is this sensor, do i use this on the rb25?

And when the engine is in, what do i connect these hoses to?

Cheers, Josh

[BHDave]

keep the top one, it's part of your climate control. You will have to run a couple of wires for it from one of the dash plugs and pinch the original plug off the rb20 engine loom.

ditch all those hoses unless you are running the factory boost control. Run a single feed from somewhere in your piping to the actuator. You'll have to add a nipple as the rb20 piping doesn't have one.

[DC Drift]

just had a RB25VCT/30 put in my 32gtst thought i might aswell post pics and point out that although i have heard of people using the RB25 inlet manifold we couldn t get it to fit under the (aftermarket)bonnet because the RB30 block sits around 40mm taller in the engine bay. So now my RB has a greddy manifold(RB20 throttle), which then necessitated moving the clutch master cylinder along the firewall closer to the brake booster. Also changed the gearbox to the 25 and changed the tailshaft. Trying now to get the RB20 ecu to run this setup with SAFCII(still considering ecu options), still alot of work to do however this should give an idea of how it fits in the 32 bay.

r33 clutch master is what i used.. much shorter than r32 item...

[rad100]

anyone got a step by step on the wiring side of things with pictures?

just want steps on all the wiring into stock rb25 ecu..

this is all i need done for mine atm!!

cheers..

[NICKCEFFY]

+1,

I've got most of mine sorted to but just need confirmation of what wires are needed/un needed and how the wires on the 5 pin plug under the power steering resevoir connect up to the 32 ones in the same spot, i.e colour to colour.

Cheers nick

[DC Drift]

quick question guys do i need to earth the vct wire (blue white trace) or does it need 12v constant, its not working :S

[BigC1988]

Is there someone that has a wiring guide for the swap??? (I have a S2 Rb25)

[Hibino]

Is there anything to look out for when putting in an RB25 NEO into an R32?

Using neo ecu.

[Härski]

which wire i connect to ground, if i ground the VCT solenoid to activate it? it