[200q20v] Boost terminoligy

Neil Swanson neilsphoto at yahoo.com
Mon Jan 21 13:34:43 EST 2002

Hey guys

Something that I think is getting tossed about a bit
and may have some scratching their heads is the very
term "boost.

You just need to think of boost as pressure in the
intake tract, well into the cylinders as pressure
rises there too of course.

But  boost in itself?, say my new wizbang ECU lets me
run 25lbs boost.   Thats just a number, pressure in
the intake and has nothing to do with the quality of
the air.
 Can that air make HP?  Better yet can it make torque?
  25lbs of boost can make power, can make detonation
too.  So can 15lbs of boost.

As the intake air temps go up, and they do thrashing a
K24 or an RS2 outside their design ranges  power goes
down because the "quality" of the air goes down too.
Lack of oxygen in the heated air.  I used to refer to
it as "crap air".

No I didn't say that right.  Less air mass is what I
think I mean to say.  It isn't the volume of air
you're pumping that makes the power.   Was that more

I wish IC upgrades for 200s and S4/6s were available
and easier to install 'cause past experience on other
turbo cars has proven to me that with a good IC
everyday is January in CT, well in regards to charge
temps anyway.

I was big time into tuning the 2.3 Ford turbo in my
Xr4ti a few years back.  When I did a turbo upgrade I
kept the exhaust housing the stock size (.48) after
driving others'  cars with the next step .63 exhaust
housing.  But on the cold side I went to a Buick Grand
National  wheel and housing.  Stock turbo was good for
240hp worth of flow, The GN housing could provide for
320hp, but I never had the fuel system to handle the
air so I never saw the 320hp.  The 320hp number would
have arrived at @22psi boost.  The turbo was in its
sweet spot at that pressure ratio.  i forget exactly
how  TEC quoted the specs but it was something like
"32lbs/hr (minute?) at a PR of  1.5bar (22psi). " Rule
of thumb is if you have the fuel you can figure that
32lb number times ten for possible hp so 320hp was
possible with that turbos capabilities.  Of course
everything else has to be up to it.

NAC,  few years ago I had the great chance to go crew
with a friend who was in search of, and got the
following year into the 200mph Club at the Bonneville
Speed Week in a Merkur Xr4.  HUGE air to air IC and a
HUGE air to water IC.  His turbo was rated at air flow
sufficient for 800hp. Just add fuel!  And he did.
Three pumps and BIG lines.

 Other turbo cars ran hundreds of pounds of dry ice
over the rear tires that  with all the heat shed would
make nice hot cups of tea after a full on 7 mile pass.
  BTW the Xr data logger showed rear wheelspin still
at 180mph!!!!!

Anyway boost in itself doesn't mean hp, just consider
it when throwing numbers out there.

Thanks for your time

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