It appears I'm getting 0.5 Bar boost pressure at best!
This is measured at the turbo (T piece in the pipe between the turbo and the wastegate actuator)
Even getting this is hard work - initially it was registering barely 0.1 Bar until I stopped and revved the engine quite hard. After that it got up to the 0.5 Bar
Any thoughts?
Are you measuring the boost under load, or with the vehicle stationary? You can rev your engine as hard as you like whilst it's stationary and the waste gate arm will not budge, nor will you get a very accurate boost reading. The waste gate actuator arm will move when the engine is under load to ensure that the preset boost is maintained, rather than allowing the turbo to continue producing more and more boost. You can check to see that the waste gate actuator arm is free. Take a pair of mole grips and clamp them onto the flat edge of the arm that pivots on the exhaust manifold. Then push your mole grips towards the bulkhead (opening the waste gate) and it should move quite freely. If it was stiff, or if there isn't no movement at all, the spring has either seized, or the mechanism is jammed. It should automatically spring back towards the turbo. Work the arm a bit t free it up and it might be worth giving it a bit of lubrication. Oil will eventually burn off, but it will work its way into the mechanism and the pivots to free it up if its been a little stiff.
If your waste gate is working properly, the boost gauge will reach a maximum figure (not sure what it is) and it should not exceed that. It should drop every time you come off the throttle or dip the clutch. If it continues boosting then the waste gate isn't opening and you might end up popping an intercooler hose or bursting your intercooler assembly.
As for what 'jmattely' said about movement in the compressor, it's not true that there should be no movement. There WILL be slight (but not excessive) movement up down, left and right. The compressor works on a 'wet' bearing that is made when oil is forced into the compressor housing race, via the oil pump. When the engine is off, there is no pressurised oil in the compressor housing and therefore the bearing "collapses" as so to speak, allowing the spindle to jiggle slightly.
As for the whole 'sluggish' issue, ensure that the insides of your intercooler pipes have not delaminated, or that the inside of the CAF (cold air feed) pipe between the air filter and the turbo inlet has not collapsed. If the inside of the pipe is 'flappy' or delaminated (not always easy to tell), the pipe will be sucked shut and thus the engine will be starved of air, creating poor performance and lots of black smoke. Have you swapped your air filter? Cleaning your intercooler out with paint thinners will also work wonders. The intercooler may have become gunked up with oil (from the cyclone breather) over time, which reduces air flow through the intercooler matrix.
-Pos
