RB25DET bolt up questions?

[Chris-280ZX]

Ok, after talking to James a bit for the other day, we were discussing the RB25 as a possibility for a motor swap for me. He couldn't remember if I'd need custom mounts or not. The RB25 is a direct bolt up from all I've read. But after searching and searching, nothing seems consistent as far as motor mounting or tranny. Apparently, there is a stock position and the position as far back in the engine bay as possible. Which of these require the custom mounts...or do both? I hear Brad or someone on here sells them. What is the final word on these?

 

Also, for those of you who have gotten a RB series motorset, how lucky were you? Did you get stock I/C, fuel pump, working turbo, etc.? How clean? Mileage? From who? How much custom fabbing (besides the obvious) was needed to get things to go in the right places? Thanks for your time.

[Guest 81na ZX]

The only things a RB engine bolts into are some Holdens and Skylines.

A 240sx is CLOSE to a bolt in, but you have to put infar more than just the engine.

[cheftrd]

EVERYTHING will be custom. It would be no different than putting a Toyota engine in your car. At this point, the only thing you have going for you is that your car came with EFI from the factory, so the fuel system is pretty much there. James is a smart dude and a good fabricator from what I've seen of his work. I'm sure he could make it work for you.

 

Matt

[Guest Aguyandaredhead]

OK, since no one who has done this swap has chimmed in I guess I will...First if you are on a strict budget forget about it.. I have been on this swap since about march and I am nowhere near done yet. I have about 12G in a bare chassis that is all caged up and the motor, trans and LSD from a 96 Skyline all mocked up in the car and all the fabrication done to make it fit.. I have some pics in my gallery I think and many more I can email if you are interested in seeing what is involved.

 

Ok the bolt in you are misunderstanding is if you take the stock crossmember and the factory motor mounts from a Japan only Z31200 a RB25det will bolt in. It however will put the motor way too high, as well as too far forward to keep weight dist as close as possible. the factory intake on the RB25det will also not clear the hood and the oil pan is a front sump from a RB25det and therefore it will conflict with the crossmember. The pan from the Z31200 ( mind U a Japan only car) will bolt up and then make it a rear sump which will give you clearance. Oh you need the sump pickup tube as well. Needless to say this is not the best way to go, aftermarket motor mounts would be prefered.

 

Ok Brad D is no longer making any parts related to RB swaps. I contacted him when I started this project and ended up having to make mine myself. I have a jig made that will allow me to make multiple if people are willing to buy them. I will ask the same price as he did which was 100 bucks. I am not advertising this though (until now). Mine keep it as far down and back as possible just as his did. You will still need the oil pan I described above as the sump pickup. The intake also has to be addressed, I had one made in New Zealand that is awsome (read not cheap) as well as a equal length stainless steel header for a much larger turbo.

 

You really should not use the factory ECU as the octane level in Japan is rated much higher and you will get detonation with our 93 octane if you plan to try and up the boost. I have a fully programmable laptop adjustable stand alone fuel and Ignition computer that eliminates the stock ECU and harness as well as many unneeded extras on the RB25det. It is made by Haltech and is called a E11v2 if you want to reasearch it. It was expensive but I think worth every penny when it comes time to tune it as it is also tune on the fly so to reduce dyno time. There are a few systems that are being used with good sucess that are way less money like a SDS system or maybe even a Megasquirt..

 

As far as what you get when you buy it. You get what you pay for. I bought a full clip that had only 45K so it is fairly low milage compared to most.you can expect to pay around 3-4k depending on what you get with the clip. I also got many extras sold to recoup some of the cost.

 

Then you are going to need a good front mount intercooler ect.. Should I stop now. Don't get me wrong I am not trying to discourage anyone I just know when I started reasearching this myself the info was limited and it was hard to get any straight answers. I have much more info so if you have any more questions just ask I will be glad to help.. I also have a ton of build pics I could share but the picture space we are provided here will not support very many..

 

Jeff (Aguyandaredhead)

[Vintage-TechZ]

I believe Bernard Plett still has a few RB25's and 1 RB26 left in Reno Nevada for sale.He was so professional and helpful it was just great !He is a English teacher in Japan and comes stateside frequently to visit family and friends.I simply timed it so I could drive up from Missouri and pick EVERYTHING up at once.He can set you up with the 2WD tranny etc,etc. In fact he is where earlier mentioned BRAD D. ,in Canada bought his from as well !

So give him a shout ! (dfbug103@kcc.zaq.ne.jp ) He's a great guy to deal with. Tell him Vince sent you hunting for a RB,he's building a bad ass R34 as we speak !

Hey Jeff, try and send your pictures to me again,the last ones wouldn't open for some reason......bummer !

Oh yeah, I just ordered a R34 N1 oil pump from him for my AWD RB26DETT Widebody Z'...........tick,tick,tick,tick.

...............Vince

[Montoya]

I am currently going through the same swap as aguyandaredhead. Maybe it's the red heads fault (I have a redheaded girlfriend as well), but it is not an easy swap. I got the engine mounts from Brad before he was done selling them and they put the motor in the perfect spot. Fortunately for me I work in the aftermarket parts industry (Advanced Engine Management) and thus I get hooked up on both parts and tuning, still it is very expensive. I got the motor, trans, harness, turbo, and all accesories from a friend for $1,500. I plan on keeping the internals stock for now however I will be running a garrett GT35 turbo (sponsor our NHRA Drag Car so I got it for free), custom exhaust manifold (AEM bought DC sports earlier this year), greddy intake manifold (~ $550), Greddy intercooler (~$1,200), Stand alone EMS (AEM), Custom wiring harness (~$500), CDI system (AEM), Head ported and pollished and flowed (R&D dyno service ~$400), and those are just the big things. Not to mention you will need a custom driveshaft (~$400). Basically, if I didn't have the hookups I have, this would be approximately $10K. Aguyandaredhead, how did you make your trans mount and do you have any pics? I am still collecting parts and I will be installing everything after christmas. My motor and tranny are in but the trans mount is not completed yet. I encourage anyone to do this swap if you are looking for a fast, reliable, easily modifiable swap. I discourage any people who are attached to their money from doing this swap. My redheaded girlfriend seconds that...it makes for smaller christmas presents.

[coupe79]

the oldest Rb swap post on here and it make the most sense ,

[helghast7]

^not really, all this information is pretty dated, the swap has gotten so easy over the years that its pretty much plug and play, with the right know how and some luck, you could do the swap bare minimum for 5k.