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This thread is designed as a guide for those who are thinking about fitting a genuine Nissan turbo kit from a GU TD42T Patrol to a naturally aspirated TD42 GQ or GU.
I have done this conversion myself a few years ago on my first GU, a '99 model wagon, so I speak from experience. Unfortunately I did not take any photo's or keep notes, I was not involved in Patrol forums at the time.
This thread relates to the early GU TD42T kits that had the water cooled turbo, later GU's did not have water cooled turbo's.
The parts you need in the kit
*Turbo and flange gasket
*Exhaust manifold and preferably heat shields as well
*Alloy turbo inlet pipe
*Alloy turbo outlet pipe and hose and hose clamps
*Alloy cross over pipe (sits over the rocker cover) and hose and hose clamps
*Alloy inlet manifold adaptor and gasket
*Air filter housing
*Plastic inlet ducting and hose clamps
*Oil and coolant feed and drain pipes
Missing from this pic are the inlet manifold adaptor and exhaust manifold, and hoses that connect the alloy turbo outlet pipe and cross over pipe.
Shown assembled.
Other parts you will need
*Full exhaust system
*Other bits that I can't think of right now but will add later!
*Remove the air filter assembly including ducting and pre filter if fitted.
*Remove the alloy air fliter adaptor from the inlet manifold.
*Remove the air filter housing mounting brackets from the inlet manifold and rocker cover.
*Remove the exhaust manifold and complete exhaust system.
EXHAUST MANIFOLD
Assuming the exhaust manifold studs are in good condition (best practice would be to replace the studs and flange gaskets, I reused both) give the the studs a light smear of copper coat anti seize and bolt the new exhaust manifold in place. At this stage leave the heat shields off.
Notes; GU exhaust manifold will bolt straight up to any TD42 head.
TURBO
Loosely bolt the turbo to the exhaust manifold (again best practice is to fit a new gasket) with 2 nuts.
Things get a bit more complicated here but are still well within the abillities most with basic mechanical knowledge and competence on the tools.
Turbo oil feed
Most naturally aspirated TD42 engine blocks were not drilled and tapped for the oil feed required to feed the turbo. The oil feed line on TD42T taps into a drilling on the front LHS of the engine block, if you fit the turbo onto the manifold with the oil feed pipe attached you should be able to see roughly where that drilling should be. If the drilling is there just remove the blanking plug and fit the banjo bolt with copper washers.
If like me you were not that lucky then you will need to get a custom braided hose made up. I purchased and fitted a T-piece under the oil pressure sender unit on the RHS of the block and ran the braided hose around the front of the engine securing it to the oil pipe that feeds oil to the vacuum pump (red arrow in photo shows the pipe - Photo from "Modded GU"). I used a piece of string to measure what length of hose I needed and got my local hydraulic hose supplier to adapt the right length of hose to the original but now shortened turbo oil feed pipe.
Now for the messy part.
If your lucky (I wasn't) there will be a big blanking plug in the LHS of the engine block roughly inline with exhaust port no.4 and just above the sump, if you have this go down to your local Nissan spare parts and buy the screw in oil drain fitting and fit it here.
If you don't have the blanking plug then you will need to drain the engine oil and remove the sump from the engine. Before you remove the sump have a look at where the oil drain pipe from the turbo comes down and mark on the sump where the fitting will need to be welded/brazed in. It needs to be up high in the LHS of the sump. In the last photo of the previous post you can see where 'Modded GU' has welded his fitting in, I had mine brazed in a similar position but used the original screw in fitting that would normally be screwed into the block.
Refit the sump, from memory there is no gasket, just a bead of silastic.
The oil drain pipe will need to be extended or a length of hose fiited to allow for the extra length of the required to get the drain down to the sump.
Coolant feed
From the factory GU TD42T had the turbo coolant feed pick up bolted (banjo type bolt) to the lower thermostat housing, indicated by yellow arrow in first photo. You can see in the second photo (non turbo thermostat housing) an undrilled boss on the thermostat housing casting, yellow arrow again.
The easiest way to pick up a coolant feed is to do what 'Modded GU' has done and replace the heater hose pick up with a T-piece (indicated by red arrow in photo). You will need some sort of step down to get the diameter down the same as the turbo feed pipe so using a T-piece with a female thread for the horizontal (when fitted) outlet will make life a lot easier. The feed pipe will then need to be cut down and a suitable piece of hose fitted between the pipe and the T-piece.
Photo by Modded GU
Coolant drain
The coolant drain needs to be connected to the return heater hose indicated in the photo below. It doesn't really matter where but I would put it near the back of the engine bay. Cut the heater hose and fit a T-piece, preferably use a T-piece with a female thread in the bottom of the T so you can adapt down to the same size as the turbo coolant drain pipe. The pipe will need to have the banjo fitting on the end cut off and a length of braided hose fixed to it, I got my hydraulic hose shop to do this for me.
If you are working on an early GU with a naturally aspirated TD42 you may find as I did that there is already a small T-piece in the heater hose near the firewall. The T-piece on mine was not being used for anything and was blanked off with a rubber cap, I simply removed the cap and fitted the hose straight on and secured with a hose clamp.
Once you get this far most of the hard work is done. You can now properly fit the turbo to the exhaust manifold and fit the heat shields. The inlet ducting from the turbo to the inlet manifold can now be fitted and secured.
Air filter
The air box from either a TD42T or a ZD30 can be used, the base of the airboxes (filter housings) is the same and will fit neatly in the front left corner of the engine bay, but you may need to drill one or two holes for the mounting bolts.
If you have the TD42T air box and ducting as shown in the first post then you can just bolt it all together. The plastic ducting will have a fitting that the PCV hose can connect to, though you may need to source a length of oil resistant hose.
The photo above shows where the PCV hose attaches to the inlet ducting if you have a TD42T airbox and ducting. This is a very rare GQ Safari Autech with factory fitted TD42T.
My kit didn't come with an airbox or plastic ducting so I found a ZD30 airbox with airflow meter housing still attached(some say the ZD30 airbox lid has better air flow) and made my intake ducting from parts I purchased at QLD diesel spares. From memory I needed a 3" 45 degree rubber elbow (to fit onto the air flow meter housing), a 3" to 2.5" steel reducer which I painted black, then a 2.5" 90 degree rubber elbow to connect the reducer to the alloy turbo inlet pipe.
That still left me with nowhere to attach the PCV hose. To get around that I utilized the now unused airflow meter sensor hole. I made a blanking plate to cover the hole and had a fitting welded to it for the hose to attach to, it required a 90 degree fitting.
The photo above shows the position of the AFM sensor that I replaced with a blanking plate and adaptor for the PCV hose. Unfortunately I did not take ANY engine photo's of my TD42 after I turbo'd it.
Inlet ducting
Fitting the alloy intake ducting between the turbo and the intake manifold is pretty well self explanatory so I'll just add a few notes instead.
There are 2 different intake manifold adaptors, one has a overboost pressure relief vale that will vent at about 14Psi (first photo), the other does not (second photo). If you plan to wind up the boost from the standard 7Psi then the adaptor without the valve is preferable. Don't worry if yours does have the PRV, it's not difficult to find screw in blanking plugs to replace them, try hydraulics stores for them.
You will notice on the piece of ducting that sits over the rocker cover that it has a hose barb screwed in the front of it. On TD42T engines the hose that connects here goes to the injector pump aneroid/boost compensator. Naturally aspirated TD42 injector pumps don't have aneroids so this is the perfect location to hook up your boost gauge.
Exhaust
If you're going to the trouble and expense of fitting a turbo to your Patrol do yourself a favour and fit a 3" exhaust including dump pipe at the same time. While it is possible to connect the turbo to the standard exhaust it will be so restrictive and choke the engine to the point that you will be left wondering why you wasted your time and money fitting the turbo. Let it breathe and feel the full benefits of the turbo.
Replacing the standard dump pipe (the first bit of exhaust that bolts directly to the back of the turbine housing) with a 3" DP will let the turbo start to spool up/start creating useful boost pressure at much lower revs. The standard DP has an internal diameter of under 2". My turbo'd TD42 with 3" exhaust had useful boost from 1200rpm.
Photo of standard DP to be added tomorrow. I'll also put up a pic of the "racing" exhaust I made!
If you are fitting this turbo kit to an early GU then an off the shelf GU 3" exhaust is a perfect bolt up fit.
If yours is a GQ then you can still use an off the shelf GU 3" exhaust but it may need small modifications to stop it hitting the floor over the back axle.
Above is a complete 3" mandrel bent exhaust WITH dump pipe available new on EBay (from Scotts Rods) for $699
Tony
Obviously this thread is a work in progress, I'm putting in as much detail as I can remember and finding and modifying photo's as I go which all takes time.
Thanks a million Tony. This will be a huge help for me mate and I can add photos later on too. If you need more posts added then delete this one. I'll read this properly tomorrow!!!