Turbo..

Turbo...
Im using a VNT from a Passat mated to a 1.6TD (JX) manifold using turbo adaptors from Ultimate Engineering.
My aim is to use as many off the shelf parts as possible, so in the future if something breaks I can just buy one and bolt it on... and this way I can use a standard exhaust instead of fabricating something, and everything will bolt together.

Once attached to the manifold the oil feed and return points on this turbo are almost horizontal in a T3 due to the angle of the engine, so no use at all as the oil wont drain from the turbo.

So, the turbo has to be indexed to suit the position in the engine. This was one of the only things I was a bit concerned about, but its really not a big thing...

It involves splitting the turbine housing (exhaust side) from the centre housing, and rotating it until things are where you want them. Obviously its not that simple. Turbos tend to be rusty dirty things, so getting it apart can be a challenge... and cleaning it a bit messy.

Things are a little more complicated with the VNT (Variable Nozzle Turbo) as it has a plate in the turbine housing (exhaust side) with a number of "vanes" that change position depending on engine speed. This helps the turbo spool up quicker and reduce lag... clever stuff.
On the outside of this plate is a moving ring that connects all the vanes together. On the outside of the turbo is a vacuum operated actuator which moves this plate and in turn moves all the vanes together.
This actuator connects to the plate with the vanes on it in one position only (see image).
So change the orientation of the centre housing in relation to the turbine housing we need to move the plate.
Its held to the turbine housing with 3 screws which luckily for us are evenly spaced. So that gives us 3 positions it can be in its simply a case of finding the best one.

In the image below, on the left is the original orientation. The red X shows the position of the actuator connection before and after moving the plate. You'll see its moved anticlockwise by 120 degrees. Effectively moving the centre housing around 120degrees anticlockwise too... which puts our oil feed and return right where we need it.

Its then a case of putting the turbo back together and moving the actuator around the body to put it in the correct position.

Its worth noting that before you remove the actuator to check its adjustment. They are adjustable on a small wheel and locknut. Check how much the arm is away from its stop with the actuator at rest, as you'll need to set it back to this position once youve moved the actuator...

The actuator attaches to a bracket on 2 of the 5 bolts which hold the centre housing to the turbine. In an ideal world you'd just use a different two, but as you can see theyre not evenly spaced so my bracket now bolts to the (unused) turbo mounting hole (top right) and the small hole next to it.
This puts the vacuum connection close to the block, but I think it should be okay...

So, here it is bolted up. You can just see the oil return connection in the middle, and whilst it looks as though its pointing sideways, the engine of upright in the photo. Once its tilted over in the back of a T3 it will be almost vertical.

Here you can see the actuator close to the block. The vacuum connection is on the right of the canister in pointing towards the block.
The compressor housing can now be loosened and turned to point wherever I need it, so i'll adjust that once fitted to line up with the existing chargecooler pipework.