swapping rb20 for rb25 [Archive]

fitzysupercharged

27-10-10, 22:00

Alright lads been looking into changing my rb20 in the r32 for the rb25. just wondering has anybody on here done it and if so how handy is it, mounts gearbox loom etc. cheers lads.

johnbro

27-10-10, 22:38

Alright lads been looking into changing my rb20 in the r32 for the rb25. just wondering has anybody on here done it and if so how handy is it, mounts gearbox loom etc. cheers lads.

I'm sure that's a common practice around here.
There's lots of info online for these swaps too
As for being easy I don't know how handy a job it is but I'm sure someone on here will help ya best of luck with it

japstuff 2

27-10-10, 23:11

engine and box will bolt stright in you will need a custom prop, loom and ecu and all rb25 sensors then a bit of wiring done i have both pin outs for spec1 and spec2 r33 gtst let me no if u need them

fitzysupercharged

29-10-10, 21:15

thanks for the info lads, will keep yous updated on the build

Bradley_Motorworks

31-10-10, 23:25

Yeah...Mostly all bolt in...then your loom has to be spliced and re wired...
Simple when you know how...:cool:

PeterT

01-11-10, 07:47

Just to butt in, what are the pros and cons of the 25 over the 20??

And a custom prop is needed?

Can a power fc for a 20 be modded for a 25?

japstuff 2

01-11-10, 09:26

the prop on the rb20 box has a smaller spline than the rb25 so you can either get it cut ,welded then ballanced or change the ends

as for the rb20 and 25 every one has defferent oppinions all depends on what power u want

i no u can use an rb20det loom to run a rb25det with a little wiring, so would say yes to being able to use the rb20 pfc

ask richard aka(bradley motorworks) of the site he would no for sure 100% to deal with

PeterT

01-11-10, 11:30

the prop on the rb20 box has a smaller spline than the rb25 so you can either get it cut ,welded then ballanced or change the ends

as for the rb20 and 25 every one has defferent oppinions all depends on what power u want

i no u can use an rb20det loom to run a rb25det with a little wiring, so would say yes to being able to use the rb20 pfc

ask richard aka(bradley motorworks) of the site he would no for sure 100% to deal with

Cool good stuff. Sorry to invade the thread but its all the same questions and are relevant etc!

Id like somewhere around 350 bhp. Worth going to an rb25 so as not to push the little 20?

Quealy

01-11-10, 13:34

Cool good stuff. Sorry to invade the thread but its all the same questions and are relevant etc!

Id like somewhere around 350 bhp. Worth going to an rb25 so as not to push the little 20?

Definately worth it lad, theres no comparison between 20 and 25 imo. Just a decent turbo, pfc and the normal breathing mods and your safely up into the mid 300's horsepower with the 25. Even when you do get a 20 up to decent power, they horrible to drive, they dont have the puff to drive bigger turbos and end up being really peaky. All the power ends up being high up in the rev range. Could get flamed by the 20 heads here, but iv had fair experience with both and stand by it!! 25 FTW..

PeterT

01-11-10, 14:41

Ha that's a fairly big tick for the rb25 anyways! The guy selling was saying he'd sell it to me unless someone was gobs buy it off him and have it fitted aswell, and there's a polish guy wanting that so I may be out of the equation :(

damodeane

02-11-10, 18:42

ive the full conversion here if needed