Turbo boosting issues.

[Rasputin]

I'll make this as clear as I possibly can.

Basically, have been trying to make more than 5 psi with boost controllers with no luck.

Sought some advice from a knowledgable few, and they told me to pull the wastegate actuator hose, plug it up and check that it's boosting properly.

Turns out, even with the wastegate permanently shut (infinite boost), it's still only making 5psi...........


I then decided to do the home jobby cigarette smoke leak down test.

Pulled off the pod filter from the compressor, and placed a bag over it and clamped it up.

Pulled the intercooler pipe off the intake manifold, and bagged that up too.

Blew smoke into a nipple coming off my intercooler piping, and had another scan over the turbo and intercooler couplings.


My spotter noticed smoke coming out of where the Turbine couples to the turbo manifold.

How could this be? We weren't blowing smoke through the head at all. Seems as though the smoke is travelling through the centre shaft housing, and into the turbine side where it's leaking out of the turbo manifold - turbine joint.

Something that really astounds me, is there's no audible exhaust leak...



Turbo is GT2876R, and was "rebuilt" by the previous owner. (has white marks on the blades from where it's been balanced)..

Completely and utterly dumbfounded.


Any help, would be greatly appreciated...


Dan.

[MrRevhead]

I suspect your wastegate actuator is the culprit. If it can be adjusted, adjust it (my ones in the past have been adjustable by un-clipping the rod from the circlip then winding the adjustable rod), otherwise the rod might be too long and is limiting boost.

Pulling the hose from the wastegate only limits it from the max boost the actuator can hold anyway, which means that it is somehow limiting your boost in the first place.

[Hjt]

regulated 5psi wastegate?

[Rasputin]

But if the pressure sender hose into the wastegate isn't connected, shouldn't the wastegate remain closed, and an infinite amount of boost be created?



Dan.


EDIT::: Or are you guys saying that the pressure inside the turbine is forcing the flapper door to creep open on its own accord?

It's supposedly a 4psi actuator, and the boost reaches 5psi with pressure hose into actuator disconnected. It reached 3.8psi on the dyno with it all connected up properly.



I am aware the actuator fitted to the turbo is not the standard fit. Perhaps the turbo is just too big for a 4psi actuator.

[olboy]

Try disconnecting the wast gate altogether and holding it closed with a piece of wire