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Rb20 To Rb25 Conversion

CeffyNSW

By CeffyNSW,
in Engines & Forced Induction

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CeffyNSW Community Regular

CeffyNSW

Posted
Posted

Guys

Have bought an RB25DET to put in my Cefiro, which is currently an RB20.

Thought there would have been a thread on how to do this conversion, but could not find one!

I presume it will bolt straight in, but just wanted to know about best electrical method with standard R33 loom and ecu. Also digital speedo with mechanical dash.

Any advice appreciated

Regards

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https://www.sau.com.au/forums/topic/87779-rb20-to-rb25-conversion/
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heller44 Mentor

heller44

Posted
Posted (edited)

I had this link in my favourites from before the forum software change.. If anyone can get it to point to the right place again, (search doesn't like the title for some reason :) ) it shows a very good guide to the conversion.

*old link*

http://www.skylinesaustralia.com/forums/in...showtopic=53898

topic heading was : Rb25 into R32 skyline

Edited by heller44
  • 2 weeks later...
sim_rx3 Newbie

sim_rx3

Posted
Posted (edited)

hi guys the old link isnt working i think. plus i have searched and thereis alot of info to waid through and i dont have time as the owner of the car wants it done yesterday.

okies to cut a long story short.

im currently working on an r32 that originally had a rb20.

there is now an rb25 sitting in the engine bay

(i did one a long time ago and cant remember how i did it or what i did and the info i had i can find)

so some questions -

as what im looking at doing atm is using the rb25 engine harness and just getting the pinouts for the 3 plugs that are near the ecu to plug into the car wiring harness.

swap the wires from the rb25 engine harness to the rb20 plugs so it will plug into the car harness with little fuss.

does anyone have the pinouts for the 3 plugs i need both the rb20 and rb25 diagrams showing the pinouts and wire colour with function??

any info would be greatly appreciated. plus once i have it sorted, ill post up all the info for future reference. B)

Edited by sim_rx3
blind_elk Grand Master

blind_elk

Posted
Posted

The RB20 gearbox will bolt straight up onto the RB25DET. The box appears capable enough to handle the output of the 25.

My conversion - Stagea RB25DET into a R32 GTS4 - ended up pushing 180kW to all 4 wheels, and the box hasn't shown any reluctance to continue working.

I ran a Wolf 3D ECU into it, so can't help you with the pinouts.

boot_it Enthusiast

boot_it

Posted
Posted
ok ive got the diagram for the rb25det harness diagram - http://www.gweeds.net/carpage2/rb25diagram.jpg

if someone has exactly the same but in the rb20det i would be most greatful.

thanks in advance

just a heads up you have to hook up the cat temp sensor when doing this conversion otherwise the 33 ecu goes into limp mode

(this is what happened to me when i put a 25 in to a slivia and used the factory ecu)

sim_rx3 Newbie

sim_rx3

Posted
Posted (edited)
just a heads up you have to hook up the cat temp sensor when doing this conversion otherwise the 33 ecu goes into limp mode

(this is what happened to me when i put a 25 in to a slivia and used the factory ecu)

thanks heaps man!! B)

im still chasing the diagram if anyone has one.

Edited by sim_rx3

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