<VV> Re: Turbo set up--was mileage

Norman C. Witte ncwitte@wittelaw.com
Wed, 17 Nov 2004 17:01:23 -0500


Hmmmm.

I take it the more accurate boost gauge is necessary because I am more
likely to grenade the motor with these performance enhancements.

I am wondering if I am experiencing a bit of mission creep here.  My
original intent was to end up with a basically stock appearing motor, with a
little more "pep" than stock.  I had thought to use the 150 turbine wheel
and the Jet Hot because that seemed like a simple enough deal.  Then the
issue came up of the Safeguard...

This led to discussions about 95 hp heads and all sorts of things, and now I
am headed on to intercoolers, water injection and waste gates.  All of these
are great ideas, but I am mainly looking to make a car that will be nice to
drive all summer, and maybe to be a shade quicker to build boost.

So you're right about the tangled web.

There's a "recipe book" for building a street autocross 140 on the web:

http://clubs.hemmings.com/clubsites/nvce/files/EngRcp3.htm

I'm hoping to do upgrades to my motor to about this level.  Part of my
problem, and it is the problem everyone has who wants a faster car but
doesn't have experience doing this, is that I don't know what to expect of
any given enhancment.  For example, I don't know how much of an effect I
will get from having the exhaust coated.  Will this result in a modest or
dramatic increase in boost?  I would expect the 150 turbine wheel to
decrease boost, but make what it does more rapidly.  How significant is this
change?  No idea.  The problem of course is that I don't own a flow bench, a
machine shop, a dynomometer, or a multitude of parts to experiment with
until I get the combo just right.

Would I be better off sticking with my stock heads in order to build some
limitation into the system?  If that is the case, do I need forged pistons?

Has someone recently put together a 180 hp. motor that sounds like what I
want and works particularly well?

Sorry to keep asking all these questions, but as you said, Frank, "Getting
all these changes to work well together will
require lots of research and planning."  The more radical I go, the less
likely I am to get it right, so I aim to keep my changes modest.  But I
don't want to throw time and money away changing things that may actually
worsen performance because they were not properly planned improvements.

Thanks,

Norm

> -----Original Message-----
> From: virtualvairs-admin@corvair.org
> [mailto:virtualvairs-admin@corvair.org]On Behalf Of FrankCB@aol.com
> Sent: Wednesday, November 17, 2004 2:58 PM
> To: ncwitte@wittelaw.com; virtualvairs@corvair.org
> Subject: <VV> Re: Turbo set up--was mileage
>
>
> Norm,
>     First, you definitely need to add a boost gauge that
> shows every psi (or,
> even better, every 1/2 psi) so you can tell what effect on
> boost level these
> changes produce.  I'd also recommend having TWO cylinder heat
> temp gauges, one
> for each head.  And you should consider using a wastegate to
> keep control of
> the boost level.
>     If you're planning on going over 15 psi boost, then you
> will need the
> forged pistons.  The Jet Hot coatings on the exhaust system
> should be applied to
> the INSIDE of the manifolds and piping to try to limit the
> metal temp.  If you
> don't do this then the stock crossover pipe will overheat and
> disintegrate
> likely where it makes the big bend going from horizontal to
> vertical.  (Go
> ahead, ask me how I know this.(:-)  In addition,
> overtemperaturing the crossover
> pipe between the heads will result in excessive thermal
> expansion and loosen the
> bolts to the manifolds, resulting in exhaust leaks.  To
> prevent that, you
> need either a slip joint or a bellows connection in the
> crossover pipe unless you
> can correctly apply the Jet Hot coating INSIDE the piping.
>     Follow Bob Helt's recommendations ("The Classic Corvair")
> for setting up
> squish/quench spacing in the 95 heads.
>     Regarding the Petronix II and the SafeGuard, I'd suggest
> you contact Ray
> Sedman to see if the Petronix I might be adequate, since the
> variable dwell
> feature of the Petronix II is duplicated in the SafeGuard.
>    Even with the stock 10 psi boost level, you should add either an
> intercooler or water injection to bring down the temp of the
> air out of the compressor.
>  The engine can only take in a certain VOLUME of air in each
> revolution.  The
> cooling will increase the DENSITY of this air so that the same VOLUME
> contains more WEIGHT (mass) of air, and, of course, the
> oxygen that is part of it.
>     Getting all these changes to work well together will
> require lots of
> research and planning.  And of course, you might be limited
> by cost factors.
>     "Oh what a tangled web we weave, when first we try to get
> more power".
>     Good luck,
>     Frank Burkhard
>
> In a message dated 11/16/04 1:50:06 PM Eastern Standard Time,
> ncwitte@wittelaw.com writes:
> Wow.
>
> This is interesting.
>
> So to get to specific cases, assuming that I want a
> streetable but better
> than stock performance motor of the following:
>
> Stock carb with vacuum port
> 180 impeller/150 turbine wheel
> Jet hot coating on exhaust manifolds, exhaust pipes
> .030 over forged pistons
> 95 hp heads
> 95 hp distributor
> Pertronix II
> Flamethrower coil
> Safeguard
> NA vacuum advance
>
> What would you keep?  What would you skip? What would you add?
>
> Norm
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