Date: Thu, 11 Jul 2002 13:45:58 +0100
Reply-To: Clive Smith <clive.harman-smith@NTLWORLD.COM>
Sender: Vanagon Mailing List <vanagon@gerry.vanagon.com>
From: Clive Smith <clive.harman-smith@NTLWORLD.COM>
Subject: Re: Custom Van Side Scoops
Content-Type: text/plain; charset="iso-8859-1"
'...not sure how much of a "ram-air" effect they do, but they look
interesting'
There is no appreciable ram-air effect until travelling at about 100 mph, a
quick calculation shows that if you can recover all the dynamic head at 90
mph, it will increase the static pressure by just under 1%. Mind you, I
wouldn't mount them facing backwards!
At 180 mph this will be about 4%, definitely worth having - hence race cars
and aeroplanes paying some worthwhile attention to this.
The more powerful effect of scoops is to pick up the air well above the road
surface where it is cooler - increasing density and reducing charge inlet
temperatues.
Cooling the engine bay.
'...anyone know the actual thermo-dynamics of this?'
This is barely thermodynamics, its more aerodynamics and fluid flow.
However, theres a very good article on the web about soundproofing and
cooling the vanagons - I think its on vanagon somewhere - pictures etc. The
main thrust is sealing the heat exchangers and cooling ducts properly
ensuring the air goes where its meant to. Keeping engine bay temperatues
down is a good idea.
Clive Smith
'88 Syncro Transporter
----- Original Message -----
From: <JordanVw@AOL.COM>
To: <vanagon@GERRY.VANAGON.COM>
Sent: Thursday, July 11, 2002 5:44 AM
Subject: Re: Custom Van Side Scoops
> In a message dated 7/10/02 2:47:46 PM Eastern Daylight Time,
> thoma@MINDSPRING.COM writes:
>
>
> > If there's somewhere I could post a couple of pictures of the passenger
side
> > mold "plug" I'd be happy to so you can get an idea of what the finished,
> > unpainted, fiberglass scoops will look like. I have no idea what to
charge
> > for these things, but suffice to say I have probably 100 hours of design
> > and fabrication work in them up to this point. Actually making a couple
of
> > scoops will probably only take several hours, including about $20 worth
of
> > materials. Let me know if you're interested and what you think they're
> > worth.
> >
> >
>
> actually, Winkler of Germany makes some, which ken wilford (Van-Again)
> sells.. usually most of Winklers stuff is junk, (my personal experience)
> but the scoops they make arent too bad. ive seen some in person. not
sure
> how much of a "ram-air" effect they do, but they look interesting.. i
dont
> think i'd pay the $200+ that they cost, tho.. if the ones youre
> contemplating on making are more affordable, as well as asthetically
> pleasing, id be very interested..
> on a side note - i think the main purpose of the rear vents is a heat
outlet
> - heat rises.. dissapates out the vents.. the introduction of more air
into
> the engine compartment has been a long-debated issue.. moreso with the
> aircooled vans.. (the majority of the cooling the WBX gets is from the
> radiator) i remember reading a old Gene Berg article on the addition of
> aftermarket side scoops to a '67 bus - whether or not it helped cool the
> aircooled engine.. anyone know the actual thermo-dynamics of this?
> chris
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