Stagea Turbo transplant time!

Well it’s time – after months of sitting under a tree out the front of my place and getting covered in tree sap at an alarming rate, it’s time to swap out the turbos on the Nissan Stagea and hopefully get things back to where they were before the boost disappeared and was replaced by worrying smoke..

Welcome to Stagea Turbo transplant weekend!

Since this is the first time in replacing the Stagea turbo and being a job I only want to do once (do it right and never worry about it again), I’ve assembled both help and supplies to make this task go as smoothly as possible. (Read: It didn’t but I was glad for the assistance!)


Baz is no stranger to working on my cars – as an ex-mechanic he has helped me tool on the Rx7, The Soarer and provided advice on the WRX when I had it too. This is the first time he’s worked on the Stagea but having him handy means the job will be done correctly and in half the time.


A second hand unit from an R33 GTST (stock Nissan 45v4). Removed to be replaced by a bigger one for the GTST it came out of, it’s been in my shed for a couple of weeks ready for transplant. The housing part is a touch smaller than the OP6 it will be replacing but anything from an R33/R34 I’ve been told will fit and work just fine.

Stagea turbo


A kit off eBay from Mambatek, turbo gaskets for an RB25 engine with everything from exhaust gaskets to the turbo elbow gasket and the one for the oil drain as well as plenty of copper washers. Far cheaper to buy them all in one pack and far cheaper to get that pack from eBay. A perfect fit for my replacement Stagea Turbo.

(I can’t seem to find the full kit on Amazon but here’s a couple to get you started.)

Rb25 mamba turbo gasket set


Since oil starvation (or too much oil) can kill a turbo, it’s a very good idea to get a new turbo oil feed line to reduce the risk of that happening anytime soon. So replacing the factory line will be this one I had made up at my local Enzed store. At just over $100 it was a little pricier than ordering one online but I know that once installed it will undoubtedly outlast the car itself. I’ll be using the original banjo bolts unless they’re in awful condition in which case back to the shops I go!

(Sadly we didn’t end up using it as will be explained later on)

Stagea Turbo oil feed line


Since we have to drain the coolant as part of the process, it’s a great opportunity to throw in some fresh stuff. Same with the oil and filter as I’d rather brand new stuff going through the replacement turbo rather than the old stuff (which was changed 3 months ago but still)

The Oil – Penrite HPR-5

The Filter – z145A

Coolant – Penrite Green (I ended up buying this twice due to one bastard banjo bolt not behaving..)


A full socket set with long and short extensions and a breaker bar will come in handy as will a pair of jack stands (to help get to unbolting the dump pipe connected to the exhaust as well as reaching a couple of the banjo bolts). I’m expecting a lot of 10mm bolts for shits and giggles. Plenty of rags too because undoubtedly things will get messy from here.

A full set like this should do nicely

Depending on how long it’s been since bits have come off your RB25 (and I suspect no one has touched the bolts on the turbo or the exhaust on mine for the last 21 years..) you might find some penetrating oil handy in loosening things up too – I ended up grabbing a can of LP7 Lubricating spray from Repco.

Also used during the transplant – screwdrivers for various hose clamps, pliers to squeeze hose rings off, spanners, wrenches, towels, coffee, 10mm ratcheting spanner, shifters, water, band aids, degreaser, JB Weld gasket sealant and a doughnut from the local market. A magnet on a stick to get dropped bolts as you will drop many a bolt during this.

Oh and a pair of heavy duty Jack stands. You will be getting under the car a few times, make sure it’s safe before crawling under there!

The order

A massive shoutout and thank you to Johno G on Youtube who created this brilliant 3 min vid on what needs to come out and in what order in order to get to your wayward turbo. You’ve got three mins handy don’t you? This will be a massive help.

It was such a help for me, I built myself an order list to refer to when we wondered what needed to be wrenched out next.

rb25 turbo removal

As you can see by the stains, it was referred to often. And then you go backwards to put everything back in again!

Game time

While the oil and coolant drained underneath, we got busy working through the list pulling out things in order as we went and sorting them into piles complete with all their fastenings to prevent confusion later. Be aware that even though you’ve drained the coolant earlier, a decent amount will gush out still when you get to the banjo bolts on either side.

After tooling away for a bit and a bit of a wrestle, we finally got the Stagea turbo and dump pipe out for closer inspection. It turns out it too was a 45v4 Nissan Turbo only with an OP6 housing and where the turbine should be there was…well not much at all really.

This is what the Stagea Turbo should have looked like:

45v4 Nissan Turbo

And here’s what we found.

Blown 45v4 Nissan Turbo

No wonder all it could do was blow out oil smoke when you put your foot down…

As weird as this sounds, I was very happy to see this because it meant that it was definitely the turbo that needed to be replaced and not something I couldn’t identify. Once out and swapped over, the next challenge was to get the new one in and sitting happy. Here’s a few things we found along the way.

Top tips

-This is not a job you’d want to do yourself. Two will make it go a hell of a lot quicker, especially with one person under the car guiding things in while the other one lowers parts from up top. I’d hate to think how long this would have taken without Baz’s help. Three would be even better provided you have enough beer/coffee on hand.

-Maybe it was this new turbo I bought but we had one hell of a time getting both the coolant banjo bolts back in because they gave us zero play to work with. Either you lined them up exactly or you had no chance. Given the two copper washers you had to install with them, it made things even more fiddly. Then when you thought they were tight, they’d leak. We lost a fair share of new coolant just when filling because the seal wasn’t tight enough and Baz continued to tighten the one on the front side of the turbo until it finally stopped dripping. (You can access this front bolt just by removing the turbo heat shield).

-There is a small bracket further along the line for the front coolant feed which can be undone to make moving the line a little easier.

-Have lots of spare copper washes on handy. You’ll work out pretty quickly why when they go flying off these damn bolts never to be seen again.

-The oil one on top of the turbo went in just fine in comparison though. However I had to reuse the factory line again because it has the necessary 1mm restrictor for this turbo built in while the banjo bolts for oil did not. If I swapped in the new line, one of the new bolts would have to have a restrictor and since we didn’t have one handy, we couldn’t use the new line.  Oh well.

-Johno’s video shows taking out the turbo and the dump pipe to the cat out in one hit. Separating the exhaust parts and then bolting it to the newer turbo made things difficult to move around going back in and we found if you unbolt (if you can) the next section just after the 02 sensor you’re working with a lot less weight. Bolting it back under the car later is fairy easy and it’s only three nuts.

-Take the oil drain out when the turbo is removed and bolt it to the new unit before putting them both back in. This would have been a lot easier then trying to put it back by feel (especially keeping the new drain gasket in place.) In the end I had to reach in from under the car to guide it into place.

-Keep the elbow off the new turbo until after you’ve replaced the exhaust manifold heat shield.

-Cover the ground under the car with blankets or rags to make cleanup far easier.

-You’ll need to remove this undertray to get to your radiator. If it’s anything like mine, its the perfect time to hit it with degreaser and get rid of at least 20 years of road grime..

-Be prepared to laugh at the state of your old gaskets

Nissan Stagea turbo gasket

-If they haven’t come out in a while, some of your parts will be covered in all sorts of gunk and grime like this hose that runs right down to the front turbine. Clean as you go which will make things easier when tightening back up later.

-Because of the spilled coolant (this is unavoidable) you will have some coolant smoke when you start the car up later. It will disappear soon enough.

So after two afternoons at it, how did we go?

She’s alive! The Stagea Turbo Transplant was a success! Boosting happily, no smoke to write about and this latest turbo doesn’t sound like a police siren going off which is awesome. It took the best part of two afternoons over the weekend and I got drenched in coolant but worth it in the end. Now onto the next job!

As for the old blown turbo, it’s gone off to Melbourne to a happy Skyline and Stag owner who plans on getting it rebuilt, high flowed and with an uprated actuator. Good luck Luke and glad to hear the old snail will live again!

(The new feed line is still for sale, if you need one let me know!)

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