Further on Re: <VV> Turbo charger problem

[frankcb at aol.com]

Bob,
     Of course you are correct.  Leaks that in UNturboed cars would be INsignificant turn out to be quite significant as far as reducing or even eliminating turbo boost.  So with turbo engines, ALL exhaust leaks UPstream of the turbocharger are significant!
     Thanks for catching my error.  I'll have to proofread my outgoing mail better and not simply depend on "spellcheck" to do it for me.(:-)
     Regards,
     Frank 
 
-----Original Message-----
From: bob mccrum <bmccrum at comcast.net>
To: FrankCB at aol.com
Sent: Sat, 7 May 2005 10:15:59 -0500
Subject: Re: Further on Re: <VV> Turbo charger problem


frank, I have been following your advice to cliff on his not getting boost,
in your last post, you said he should be looking for "significant leaks".
Perhaps you meant "in"significant  leaks?  Kinda changes the whole meaning,
if you know what I mean. The knowledge is awesome.
Thanks, Bob "know more about words than Corvairs" McCrum
----- Original Message ----- 
From: <FrankCB at aol.com>
To: <cliffdar at sbcglobal.net>; <virtualvairs at corvair.org>
Cc: <JVHRoberts at aol.com>; <deltainc at grm.net>; <ronh at owt.com>
Sent: Saturday, May 07, 2005 10:08 AM
Subject: Further on Re: <VV> Turbo charger problem


> 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
> >
>
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