Jump to content
SAU Community

Recommended Posts

Hi guys this is just an idea at the moment not a serious plan but is it worth doing a rb25 swap into a r32 skyline. I have an rb20det at the moments which is fine for now but I was wanting to eventually get a rb25 and rebuild it and put it in my car but is it hard to do and what are some problems with doing it thanks.

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/
Share on other sites

I have had so many problems, it is so definitely not worth it. i still havent finished and ive been working on it for a while.. i changed it over caz my rb20 was hunting and i had the rb25 lying around so thought after reading it would be easy enough. I have plugs that dont fit, all the looms change. Dont reuse the rb20 loom, this does not work. I should of just fixed the rb20

I dont even want mine road registered so i havent worried about hooking up to body and making speedo or wipers work either.

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/#findComment-7158928
Share on other sites

We tried reusing the existing wiring and found the injectors we wired up correctly except one were the wiring colours reversed.

You lose VCT from the rb25det as the rb20 doesnt have it

The ECU fried when we tried using the rb20 ignitor box

Just whilst the engines out, change the loom straight to the Rb25det loom, injector loom, coil loom, ecu and ignitor box

youll need to figure out how to wire up the body harness and get the wipers, speedo, fuel pump etc all working.

Another issue i had was the injectors had seized from the engine sitting so long, had to hit them with 12v so they free'd up.

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/#findComment-7158966
Share on other sites

the wiring colours dont match between loom and 32 plug so youll need to do lots of reading and checking wiring diagrams etc for that to just "plug in". I posted asking for some help on this and even asking someone if theyd do it if i paid and got no answers so it was go through all the wires and figure how they transition however i dont want my registered so i ran an individual power line to the fuel pump and bypassed all of that.

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/#findComment-7163041
Share on other sites

I not being a smart ass but I did the swap in 2 weekends going from a rb20 with a broken timing belt to a running rb25 using a series 2 rb25, wiring harness and ecu.

I used all the r32 alternator, starter, power steering pump, a/c compressor, engine mounts and harmonic balancer. So it bolted back in as if it was always there then modified the r33 harness using the 32 body plugs (in the cabin) and fired it up and never had an issue, it was my daily driver and everything worked as per factory

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/#findComment-7163355
Share on other sites

if i did it again i would have dropped a V8 in it (since its for drifting and would have been a lot less effort).. TBH the rb25 and rb20 are not worth doing up, youd be better spending the money on a 32 GTR.

End of the day its your money and if your up for the hassles and cost then go for it.

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/#findComment-7167764
Share on other sites

  • 1 month later...

Series 1, i got it running, idles a bit rough but no tune, injectors were seized and hit with 12v to free. need to hook up to ECU and tune.

I am now running all rb20 wiring with new AFM (stock, dont know if mine was causing a problem) and R33 ECU. Have the rb20 coil box still there as matches wiring.

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/#findComment-7223070
Share on other sites

It's my opinion some people should not got down this path, they're simple not suited to the problems you invariably come across.

Makes no difference if you're swapping a 25 in place of 20 or going for a V8, you will have some dramas along the way.

With all the info available on the net these days, one would expect a straight Rb to Rb swap to be easy but that hasn't been my experience, you need patience and some clear headed pin out ability when it comes to the wiring.

Forget an auto sparky unless you have very deep pockets. Usually you're simply paying him to learn.

You also need to sift through the mass of mis-information given on the net, a LOT is simply rubbish.

Talk to the guys who have actually done the full hands-on swap, not the keyboard heroes.

Link to comment
https://www.sau.com.au/forums/topic/437049-rb25det-swap/#findComment-7224143
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now



  • Similar Content

  • Latest Posts

    • Jap premium will be 100 RON. You should use 98.
    • The exhaust gases are at their highest temperature as they leave the exhaust port and enter the manifold. They cool as they flow through the manifold because they transfer heat to the manifold and the manifold loses heat to the surrounding environment. Thus, inevitably, the exhaust gases are cooler as they enter the turbo compared to when they entered the exhaust manifold. So, yes, the exhaust manifold can easily get as hot as the turbine housing. Having said that, you will generally see the highest temperatures where the exhaust gases have to slow down or they are concentrated into one area - which is usually the collector on the manifold and in the turbine housing, because the gases slam into the metal at those places, increasing the convective heat transfer coefficient and transferring even more heat to the metal than they might just flowing past elsewhere. Exhaust manifold heat shields are a good idea - certainly for the stock manifold they are there from the factory. People seldom have anything like that on a tubular manifold because they are hard to achieve. Some might wrap a tube manifold with fibreglass tape - but this has a reputation of leading to cracked welds. The best case is generally to put ceramic coating onto the manifold to prevent it getting as hot (internal coating) and radiating/convecting heat into the bay (external coating). All the real heat from a turbo comes from the exhaust side. The gases entering are at ~800-900°C and the steel/iron gets nearly that hot. The compressor side is only going to heat the charge air up to <<200°C (typically not much more than 100°C). So that's nothing, by comparison. The compressor is not a significant source of engine bay heat.
    • Late to the party, specifically joined this forum as I just bought one of these and this thread has been a gold mine of info. If the OP is still around, mind if I ask what gas you been putting in yours? Mine has a Japanese sticker in the cap saying premium but it seems to get way worse mileage on premium (95) than 91. I always thought it was meant to be the other way round🤷 I do think Nissans claimed "6l/100km" is a bit fantastical 😂
    • Does exhaust manifold get hot as turno exhuast side? I have a turbo cover to managr heat in the engine bay but  nothing is covering the exhaust manifold before turbo   i know as turbo does compress air, the temp does go up however does that mean exhaust manifold would be as hot?
    • It's excellent but I'm still breaking it in so I'm not 100% sure where it'll end up. I would say it's about 15% heavier than stock and the smoothness of the slip zone is quite progressive but you need to be a little patient compared to stock or it'll bite hard and stall. Stock I got away with absolutely horrid clutch control. Like I said before I couldn't even tell where the clutch would grab when it was stock so releasing way too quickly without enough revs it would just slip and the revs would drop lower than ideal but that would be the end of it. Currently there's a bit of a nasty clutch judder if I don't apply enough revs + find the exact wrong point of the slip point in the clutch pedal but it feels like it's slowly resolving as I drive it more. I would not recommend the competition clutch unless you really need the extra clamp force. I think this clutch combined with the Nismo operating cylinder is going to be exactly what I want. Enough bite that you need to remember the release point to avoid stalling or rough shifts, but progressive enough that it's not hard to drive by any means and not heavy at all. I tried a "super single" clutch on my friend's 997.2 Turbo 6MT and that was absolutely horrid. It runs an electrohydraulic power steering pump for the clutch power boost so there's zero feedback in the clutch pedal and there was a horrific clutch shudder well after break-in due to the lack of marcel springs or hub springs in the friction disk. It felt like the slip zone was the thickness of a single toe twitch as well so it was almost impossible to avoid stalling it unless you gave it a ton of revs and just dumped the clutch instead of trying to be smooth with it. I was terrified of pulling out in front of traffic. I have also tried some kind of "super single" on an EK9 and that makes this twin plate Coppermix look like a stock clutch. Releasing the clutch pedal even slightly too quickly feels like you're getting rear-ended. The pedal is extremely heavy as well and there's no vacuum assist like the GTR.
×
×
  • Create New...