97 Stagea RB25DE to VH41DE Conversion

[Cyba]

Hi Folks! First time posting on the forums...

I guess i should start off with the car? its a 1997 Nissan Stagea 25x 4WD RB25DE

This is not the factory motor, it has definitely been swapped at some point, with no known Km's before or at time of swap. Car has just hit 278,000km/s and i was already planning on giving it a birthday, rebuild, trans flush and service, diffs, new suspension and brakes, etc. at 300,000kms...and then it died. And then instead of just getting another RB with unknown km's for too much money i went with 66,000kms verified warranty engine...

So! I have just started a project basically, I'm trying to get a VH41DE as close to bolt-in and factory looking as possible. So far the location of the crossmember factory in the Stagea 1997 25x appears to be in a good place considering the clearance from brake booster necessary to fit the engine. I am prepared for the this to be too far forward and I'm purchasing an s14 front crossmember as I've seen engine mount adapters for this crossmember. Looking at removing the viscous fan and running 2 electrics on a v30 skyline radiator for port placement and to create some more space for the engine to go further forward. Engine, trans & ECU came as a package and will be put in that way (I have suffered an injury to my left foot the stops me from running manual, only have five or so gear changes before the pains too bad to drive).

I am super lucky that my local place without a name...is giving me the OEM (if he has it available) ECU pinout from the original vehicle for the drivetrain combo and my Stagea's service manual based on VIN number!!! So here is where I'm up to.

I've started disconnecting and removing things in the engine bay to make space to take the whole engine and trans setup out. i won't go into details but if someone wants the details feel free to ask :D

Basically, I'm trying to make space at this stage and get everything disconnected bar the mounts, then ill start removing the 4WD setup...oh yeah there's a RWD to 4WD conversion here too.

The loom is pretty much disconnected from everything other than the engine. I'll be back tomorrow with some updates, I also have a friend coming to give me a hand this weekend so might get a bit done pretty quickly.

oooh and one more thing, if anyone knows about front conversions on the S-Chassis vehicles, I'm really keen to do a c35 laurel conversion on this...well I'm going to do it, but! if someone knows how that would be AMAAAAZING!

[GTSBoy]

Watch the double unicorn series on MCMTV2.  They did this swap a couple of years ago.  You will learn a lot.

[Cyba]

Oh, I have watched it, and rewatched haha. Definitely, a lot to learn there, and I'll be doing some things the same, like spacing the crossmember. I think I will try and do it with the Stagea crossmember first, if I encounter problems with engine location then I'll use the s14 one. The wiring is the bit that is making me nervous as I'm planning on running the standard Cima ECU that has come with the engine package. Not sure how well it's going to work.

[Leroy Peterson]

Sorry if I missed in the post but are you using the Cima auto and TCU? If not, I don't think the stock ECU will work (or work well)

[KiwiRS4T]

12 hours ago, Cyba said:

Oh, I have watched it, and rewatched haha. Definitely, a lot to learn there, and I'll be doing some things the same, like spacing the crossmember. I think I will try and do it with the Stagea crossmember first, if I encounter problems with engine location then I'll use the s14 one. The wiring is the bit that is making me nervous as I'm planning on running the standard Cima ECU that has come with the engine package. Not sure how well it's going to work.

It has been done a few times. Definitely easier with two wheel drive. The big problem people have is if retaining the air cond. Sorry don't have any tips for you but good luck! Oh and you will need bigger brakes - suggest K Sport or D2 type.

[Cyba]

1 hour ago, Leroy Peterson said:

Sorry if I missed in the post but are you using the Cima auto and TCU? If not, I don't think the stock ECU will work (or work well)

Yes im running the stock trans i dont know for sure but i think mine is one with tcu in the ecu. Its a 97.

 

40 minutes ago, KiwiRS4T said:

It has been done a few times. Definitely easier with two wheel drive. The big problem people have is if retaining the air cond. Sorry don't have any tips for you but good luck! Oh and you will need bigger brakes - suggest K Sport or D2 type.

KiwiRS4 thanks! Yeah as i said the car is getting a full birthday. Not sure what brakes im going to run yet. I'll see how it goes with whats in there and then make necessary upgrades. 

[Cyba]

Oh yeah what suspension does everyone suggest? Going adjustable, trying to correct the new weight balance so probably stiffer rear but ive noticed people putting s14, r33 and sometimes laurel coilovers and arms in these. I am leaning towards s14 in the front but what is the benefits?

[PranK]

Cool project, I'm looking forward to watching this one.

[Cyba]

Hahaha, thanks PranK I'll be sure to include all of the comical bits that are sure to unfold with such a swap 

[Cyba]

Oh yea KiwiRS4 I have decided to bin the A/C for now, but might try fit something later down the line. I live in a hot part of NZ so kind of need the A/C in summer

[Cyba]

So! First of all Merry Christmas & a Happy New Year to all!

Over the X-mas period, I was quite busy so I didn't get to work on the car much unfortunately but im back into the swing of things now!

So I'm not sure if you guys have realized this yet but I'm really bad for jumping into projects without doing enough research or planning.... and I found out the hardest way possible that the stagea has a slip yoke diff.... so do i need to change pinion to change it to a flange or is there some way to convert it? ill be dropping the diff next week to have a look at this myself anyways if no one replies with a confident answer (doesn't need to be correct ) I have seen its as simple as one bolt to remove the flange mount from a pinion but not sure if the slip yoke will be the same.  

I have now removed the loom from the car...also not very easy to get that plug for the ECU through the hole! The engine and transmission and front diff are all ready to come out now and I'm about to start tomorrow just pulling unnecessary stuff and relocating a few things to make some space for the VH.

So. Hopefully tomorrow the engine assembly will come out tomorrow and I can put my focus towards the diff and rear axles. At this stage, I'm going to retain the diff if I can as I believe its a 4.083 even though it only has 3x2 axles.

And if anyone has experience with making these things RWD, Is there any reason to leave the CV outers in the wheels? I can't think of a good reason off the top of my head

On another note, if anyone is looking to pick up a 4wd setup and rb25de neo with a blown head gasket get at me lol
 

[Cyba]

So! hey everyone hope your doing well sorry it took awhile inbetween posts as alot of you know shes pretty hot around oceania recently but we had a couple cold days here so got a bunch done. So RB was removed and sold on to a guy up north doing a RB30DE build in a d21, and now for the goods! We have been able to get the VH41 and trans in place and with a little modification have used the Stagea's factory trans mount, which came at a great relief. now onto engine mounts. My uncle that i build cars with is an engineering wizard who works on chassis's so this part ive passed onto him and then we continue further. space wise, shes tight. not too bad though. had to remove the steering column universal joint which we found to be nearly completely seized. probably going to have to remove, replace or modify the sway bar so thats coming out. and then it will be onto exhaust. ive been searching for the factory front y pipe or a full exhaust but no luck so far so might be a custom fab from the headers back. I have just bought a z32 4.08 VLSD and axles and a new radiator and electric fans. Might see if i can fit the factory 4.3 stuff in later :D i started this build thinking it would be a cool gimmick for a little while but im slowly falling in love with this thing. next update will be around next week.

[Cyba]

[30ed32]

Hey Cyba, looking forward to seeing this build progress, I did a vh45 in a 350z a few years ago (pic here http://i.imgur.com/r05Aktl.jpg?1 )

You need to leave the outer CVs in the hubs because that's what holds the bearing together, this is very important.  Why not keep it 4wd though?

Try to keep AC if you can it makes life better.

[Cyba]

3 minutes ago, 30ed32 said:

Hey Cyba, looking forward to seeing this build progress, I did a vh45 in a 350z a few years ago (pic here http://i.imgur.com/r05Aktl.jpg?1 )

You need to leave the outer CVs in the hubs because that's what holds the bearing together, this is very important.  Why not keep it 4wd though?

Try to keep AC if you can it makes life better.

Hey 30ed32

 

I have come to realise this of the outer cvs. Thankfully i didn't bin them.

Im not keeping it 4wd atm as its quite rare to find a factory awd vh41de and i dont have faith in a 270,000kms auto box (cant drive manual atm due to broken left foot) so rwd was the quicker option. I am on the lookout for an awd cima though.

The ac compressor is quite big. Ill be looking at other options but at this stage its out. I do definitely want to retain it though.

[Achila]

Need help 

I have laurel c35 car i brought down a stagea 4wd coversion from japan can i do the swap