Flynn

Hi there, I am from England, been aware of this website from Googling turbo related stuff but never had a reason to register until I ran into problems with my own home built turbo. The guys over on my cars specific website are outta ideas, I was wondering if anyone on here might have ideas.


I have adapted a turbo from another engine to fit on my 1.9 diesel turbo engine instead of the standard turbo and it won't go above about 7psi with a welded wastegate. The turbo was sounding broken before and would make even less peak boost so I pulled it and rebuild it but it still won't go over 7psi. The engine is a very simple mechanically controlled engine, it has no ECU, fuelling is adjusted via a screw on the fuel pump.

So far I have tried:

removed intake completely
welded wastegate
removed wastegate actuator and blocked off actuator takeoff
Checked for boost leaks (would have to be a big boost leak to cause this, I have had boost leaks before on the stock setup and they usually don't effect more than a few psi)
Turned up fuelling to max

Here are a few pictures of the turbo and mani setup:

Adapter plate (partially completed):



Fully completed plate on mani:



Turbo on adapter plate on mani:



Note I've had to block off a couple of extra takeoffs on the comp side of things.

I can only guess something is stalling the turbine shaft at higher rpms (engine and turbo) for some reason. Is it possible for a turbo to be so worn that a rebuild kit will not revive it? I am gonna have to make a decision as to what to do because at the moment this thing is slower than standard but I have spend so much £ on it that I need to be sure the turbo is junk.

Matt Cramer

Exactly what sort of turbo is this and what did it come off of? It could be the turbine housing is too big for this motor.

Flynn

Good question Matt Cramer, it came off a 2 litre turbo gasoline engine. The turbo in question, a Garrett GT2052S has been tried by other members on the forum (the Peugeot forum) and is said to be quick spooling and a good match for the engine.

However, there appear to be variants of the turbo for both gasoline and diesel engines, as far as I know those who have used this turbo have all used the diesel variant, I bought a gasoline variant by mistake because I didn't know the turbine housing was a different size.

As far as I know if it makes boost to begin with it should make more boost until the engine runs outta revs. But there is soot from the exhaust which in a diesel suggests there too much fuel to air ratio and the fuel is not getting burnt, even though a high fuel level should equate to higher boost, especially with a welded wastegate. It is a real head scratcher, unfortunately I am much the DIY enthusiast and therefore am really quite out of my depth.

Does anyone think that extra solenoid area I have blocked off might be causing problems?

Matt Cramer

The solenoid appears to be a recirculating valve - if it's blocked off in the closed position, it should be OK. If it's stuck open, that could be the problem as well.

Flynn

Yup, didn't block it off properly. I didn't pay enough attention to it, there is a hole down in that channel:



Air went down there and back to the inlet

I just blocked the outside off by plugging the dome shaped thing so the boost was just filling that and then escaping down the hole.

The final solution was a flat plate:

This has had me baffled for months, thanks for the help!