In the field of motorcycle engine performance the airbox size (volume)
is an important part of the power curve. It is then another element of engine
tuning not unlike porting, cams, and headers. The airbox becomes a resonant
chamber that is generally optimized to offset deficiencies of the other
components. We could expect considerable low end performance improvements with
the 2 liter engines and Solex carbs The fact that the market would rather hear
of "Ram Air" etc. does not change the role of this element. Inlet design needs
to slow the fast moving airstream in order to build pressure. Real air flow
improvements come from properly designed inlet opening, taper and length. The
correct sizing often looks a bit "throttled", but is correct. This is a rather
lengthy topic that is best covered in some of the specialty books on the
subject. This may be the next hot item for aftermarket!
"Ram Tuned Cold Air induction!" Bolt on horsepower and economy for your
Roadster. Only $999.99! ;-)
On another automotive list, someone was considering adding a leafblower as the
forced air system. Hmmmm?
Regards
Calvin Grandy
Vermont
----------
> From: Bob Mann <RWM@RWMann.com>
> To: Dan Neuman <dneuman@stars.sfsu.edu>; datsun-roadsters@autox.team.net
> Subject: Re: Air boxes
> Date: Thursday, December 09, 1999 9:28 AM
>
> A relief vent at the rear of the airbox is unnecessary, and if it were
> to flow substantially, it could siphon from the carb stacks.
>
> The only time you see airbox venting is in very carefully designed (i.e.
> flow visualized/modelled and wind tunnel tested) situations when
> extremely high speeds might cause excess drag, a la F-1 or Sports Racers
> (LeMans, etc.). You will also note that those cases clearly throttle
> the amount of air entering the airbox, via creative nacelle design.
>
> As for the front-to-back argument, static pressure is static pressure,
> thoughout the plenum.
>
> - Bob Mann, '69 2000 Solex
>
> Dan Neuman wrote:
> >
> > Hello All,
> > I wanted to bring up the subject of making an airbox for the
> > roadster. I had posted to the list about how all the 510 guys had them with
> > a big tube leading to a little K&N air filter out in front of the rad. I
>guess its
> > sorta a cold air induction system?? Remember??
> > Everybody said that if you do that you have to cut the back of the
> > box up to make sure the rear carb was not seeeing more pressure.
> > My question is why does the rear carb see more pressure??
> > If you have ever looked at a modern inline four motorcycle they have
>seperate
> > carbs for each cylinder and they look darn like the solex's..four little
>air horns
> > right in a row.. But they are fed by one airbox. ONe sealed airbox. This
>airbox
> > must make the carbs see equal pressure. WOuld it not be possible to do the
> > same thing to a roadster???
> > Do you see where I am going with this?? Make the airbox thing work
> > and then upstream of the airbox add one of those new style belt driven
> > superchargers.....and away I go.....
> >
> > Boy this years AnchorSteam Xmass Ale is really really good...
> >
> > Daniel 69 2000-
> > SF CA
>
> --
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