Further on Re: <VV> Turbo charger problem

[FrankCB at aol.com]

Cliff,
       At least 2 things to consider.  First is that it takes TIME and LOAD 
to build up boost.  A stock Corvair turbo car driven from stop light to stop 
light will rarely whow ANY boost.  To show boost, get the car fully warmed up 
and on the open highway.  Run it up a LONG hill at FULL throttle for at least 5 
seconds (preferably longer) and you should certainly see some level of boost 
develop.  Secondly, even a SMALL exhaust leak can eliminate any boost at all.  
You could have a cracked exhaust manifold inside the shrouding (as I did) that 
would leak away enough exhaust to eliminate boost.  It sometimes takes 
careful and prolonged searching to find the souce of the leaks.  It may well be a 
number of rather small and seemingly significant leaks that are affecting your 
turbo.  Keep looking.
       Incidentally, I would recommend at least temporarily replacing the 
stock manifold pressure gauge with a much large "tuneup" gauge that shows vacuum 
and pressure (up to about 10 psi).  These have markings at every ONE psi (mine 
has every 1/2 psi) and so give a much better indication of just how much 
boost you are actually getting, if any.
       Let us know what you find out.
       Regards,
       Frank "tracer of lost boost" Burkhard

In a message dated 5/6/2005 11:10:55 PM Eastern Standard Time, 
cliffdar at sbcglobal.net writes:

> Frank
> 
> I get none of the indications that I would expect when getting "boost," 
> (spin up of the turbine).
> 
> 1) A boost in horse power
> 2) A turbine whine
> 3) Positive pressure on the manifold gage (it tested ok)
> 
> I have taken it out on the freeway numerous times trying to get the "boost"
> 
> I have also removed the turbine and and partially disassembled it, all looks 
> good with the right clearances (I have the GM Corvair shop manuals).
> 
> I can find no leaks in the exhaust, and tried with the muffler off to 
> eliminate a clogged or a wrong muffler.  I've run out of ideas, other than the 
> wrong exhaust housing.  Still trying to find out what identifies the early and 
> late housings.
> 
> You have a manual?
> 
> Appreciate any ideas.
> 
> Cliff
>