<VV> turbo non boost

[FrankCB at aol.com]

Dan,
    Yes, the exhaust system UPSTREAM of the turbo must  be without leaks in 
order to build boost pressure.
 
Robert,
    How are you measuring "2-3" psi of boost?  Not  the original stock 
manifold pressure gauge, I hope!  Install an aftermarket  gauge with a 4" dial and 
calibrations showing every psi of boost (my Sears  "tune-up gauge" shows every 
1/2 psi of boost).  Even if you install it  temporarily in place of the stock 
gauge and hang it from the dash at least  you'll see what you're actually 
getting.  The stock gauge is calibrated in  inches of mercury ("in. Hg") and each 
"in Hg" is equal to about a  HALF psi of boost, that is, IF the 40+ year old 
gauge even works!
    Also with the loooooong exhaust piping between  exhaust manifolds and 
turbo it takes a few minutes under full load to build up  boost in the Corvair.  
Get the engine fully warmed up (300+ deg. F on the  CHT gauge) get to the 
bottom of a LONG hill and floor the accelerator pedal and  hold it for at least 3 
minutes.  Four or five minutes is even better.   You should get at least 8 psi 
of boost.  If the piping is insulated  you could get 10 psi, at least as long 
as the piping lasts without leaks.
    Frank "gauges tell the REAL story"  Burkhard   
    
    
 
In a message dated 5/30/2007 10:33:07 AM Eastern Daylight Time,  
djtcz at comcast.net writes:

It was  my experience a turbo exhaust must be so tight that an idling engine 
can be  stopped by clamping a folded shop rag tightly over the exhaust outlet 
with my  hand flat.  I think I read that somewhere and found it to be true.   
It only really matters between engine and turbo, but it's hard to pressure  
test anything but the whole system.
--
Dan  Timberlake


-------------- Original message --------------  

Date: Tue, 29 May 2007 16:32:19 -0400
From: "Robert Hawley"  <iamrgh at charter.net>

[SNIP]



Boost is meager to say the least (2-3 #) and after looking at  the exhaust 


[SNIP]



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