[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: Heat crazed mad scientist



I say we take up a collection, and have an independant test done by an
outside source. a dollar per member should cover it! then we elect a
spokesperson to publish an article.  Put the airfoil thing to rest for good.

5 dollars gets you in the "gold" club, thats where your name WON'T be
published as one of the sponsors who doubted those vendors. ;-)

----- Original Message -----
From: <John_Calabrese@ENGELHARD.COM>
To: <gmecm@diy-efi.org>
Sent: Monday, June 05, 2000 11:58 AM
Subject: Re: Heat crazed mad scientist


>
>
>
>
>
>
> "Bruce Plecan" <nacelp@bright.net>@diy-efi.org on 06/05/2000 11:54:51 AM
>
> Please respond to gmecm@diy-efi.org
>
> Sent by:  owner-gmecm@diy-efi.org
>
>
> To:   <gmecm@diy-efi.org>
> cc:
> Subject:  Re: Heat crazed mad scientist
>
>
>
>
> > In order to quantify the flow increase, and thus the talk of laminar vs
> > turbulent flow, a velocity must be calculated from the area, and cfm
flow
> > of the engine at different speeds.  Once the velocity and reynolds
number
> > is calcuated, then you can see whether or not turbulent or laminar flow
> is
> > present.
>
> >What makes this all fall apart is there is no specific velocity in a
> intake
> >tract.  The airflow is in pulses.
>
> You can talk about average velocity at the throttle body, this is the
> subject I am referring to, not the back of the valve.  The throttle body
is
> far enough away that it should se and average velocity without BIG
> perturbations.
>
>
>
>  Either way, in a stock TPI throttle body, there is a abrupt edge
> > where the airfoil goes.  Any time there is an abrupt change in
direction,
> > flow separation will occur, and it will occur easier at higher
> velocities.
> > Flow separation can be avoided or lessened by smoothing out the abrupt
> > changes in the device you are flowing air in, be it a manifold head
port,
> > or a throttle body.  The airfoils'
>
> >Using the word airfoil really is a stretch
>
>  >job is to fill in a dead spot between
> > the two openings, thus making the change in direction less abrupt.  This
> > should increase the flow due to the smaller amount of flow separation
> from
> > the side of the walls.
>
> >So, then using about the same logic here, running with the tailgate open
> on
> >a pickup should inhance mileage, right?.  Trouble is it don't work that
> way
> >(>most often).  The air "bubble" formed behind the cab turns out to
smooth
> .the air flow behind the cab and over the gate then all the turbulence of
> >having it open and reducing the size of the "bubble".
>
>
> Every design has specifics about them.  You cannot compare the throttle
> body and the back of a truck.  Stop looking for an argument.
>
>
> > trying to fill in dead spots in flow that could cause flow separation,
> > vortices, and reversion, all which adversly effect flow rates.
>
> >Which matches what I said.
>
>
> I must've missed that part.
>
> >
>
> > I do have
> > to disagree with grumpy on the fusalage being the same as the intake.
>
> >Hang in there you'll get it right eventually.
>
> > Inner flow and outer flow can differ significantly when boundaries and
> > finite areas are considered, plus everything on a plane is designed for
> > lift and minimal drag....
>
> <>Heard that stuff before, trouble is the engines don't read the same
> >material.
>
> .>Just in what you've said, one might be tempted to think the airfoils
> would
> >have to work wonders, OK, why don't the performance numbers reflect
that?.
> >I'd suggest reading some of Smokey Yunicks old stuff.
>
>
> The only way to test this is to flow the throttle body before and after
the
> installation of a "airfoil".  Performance numbers are the bottom line, but
> an increase in flow potential in the intake may be masked by many
different
> factors in the engine, drivetrain and other associated parts that we take
> for geanted as being constants.  You have to isolate the unit, make one
> change and test it.  An increase in flow is what the manufacturer is
after,
> I don't necessarily belive it will make huge improvements in performance.
>
>
> --------------------------------------------------------------------------
--
>
> To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
> in the body of a message (not the subject) to majordomo@lists.diy-efi.org
>
>
>
>
> --------------------------------------------------------------------------
--
> To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
> in the body of a message (not the subject) to majordomo@lists.diy-efi.org
>
>

----------------------------------------------------------------------------
To unsubscribe from gmecm, send "unsubscribe gmecm" (without the quotes)
in the body of a message (not the subject) to majordomo@lists.diy-efi.org