Dave

>From the Kitplanes article that Thomas J mentioned,  it seems

that the turbo turbine needs to be oversized by a factor of 2 to
allow for the fact that the

airplane installation has a steady state throttle.   In a car

application the throttle is never held open long enough to allow
the TIT to build up to a hotter

equalibrium value.  Therfore the "average" TIT in a car is a

lot lower than in the steady state airplane application.

Paul mentioned that another way to make the turbine appear

bigger is to drill a hole allowing exhaust gasses to bypass the
turbine, thereby increasing flow

rate and lowering turbine inlet pressure and temperature.
If the wastegate currently seems to have no effect on boost

then maybe you could try removing the wastegate flap all together.

The flap is most likely blocking the flow even when it is open.

Regards, Erik

That is a pretty good idea. Unfortunately the assembly is welded together
so it might not be possible to restore it. I think modifying
the back cover of the waste gate to allow the flap to open 90 degrees
might be a better approach. At least a first thing to try.

I did a 3D of a steel spacer shown here.

Also a large 3 inch exhaust tube could be welded over a 3 inch hole
in the existing back cover to allow the flap more freedom to open fully.

A bit of porting on the waste gate might help.

Paul Lamar

I have been considering that very mod, just breaking off the waste gate
door, or perhaps trying to grind it away small portions at a time and see
how it goes.  After I gather enough experience with the waste gate connected
to the actuator, I will do some testing with the waste gate always open and
see what difference it makes.  If favorable, I will probably start grinding.

Dave Leonard

I would try to save it as is Dave. 
You might need boost at 25,000 feet some day :)

Just get it to open 90 degrees first.
The second thing I would try is a little die grind porting around the
existing openings. You will need the 90 degrees to do that.

Also a second pipe would reduce the back pressure on the waste
gate portion. 

Even better. Perhaps a new 3/8 inch thick SS back cover with one 
3 inch pipe directly located in line with the 90 degree waste gate putting 
a little additional back pressure on the turbine. This would favor the
waste gate instead of the turbine. 

Paul Lamar
 
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