Accoustics is a high and arcane science. I'd rather start with the stock
and make it variable as I imagine quite a bit of math went into that air
hat. But do what you want. Not every shape of a given volume will resonate
well. But the accoustical math for resonating columns of air, or tubes, is
out there. Like for pipe organs etc. I've considered before a telescoping
intake tube leading to a K&N. The intake would shorten up as rpms rose. My
brain always gets stuck on making it telescope and airtight at the same
time; don't want no dirty air. Maybe that is your starting point.
A solenoid costs about as much as a used electric door lock solenoid from a
junk yard. The butterfly would not be a big deal.
Season your cornflakes as you see fit. I take it you already have a PVC
po-boy on your truck?
Marty
Jon Smith wrote:
> I don't see how ppl would loose a significant amount of power due to the
> "Bose Chamber"... but if so, would it be enough to warrent the time and
> expense of fabbing up a solenoid? May be easier and cheaper to mod it up
> somemore to make up for any loss ;)
>
> not tryin to piss in your cornflakes, just stating my humble opinion...
> _______________________
> Jon Smith--Raleigh, NC
> jon@fast4x4.net
> www.fast4x4.net
>
> > I posted this replying to the spark plug thread and there was no
> > response. So now I'm giving it its own subject. C'mon guys, its
> > not _that_ boring. Don't leave me hangin'!
> >
> > I was taking a better look at the underside of the stock 4.7 air
> > hat and I think I know why you guys lose a bit of low end with
> > the intake upgrades. They have a 'Bose chamber' in the air hat
> > which will make the intake resonate at a lower frequency than the
> > normal intake of that length would resonate. This will cause the
> > intake to have its peak ram effect at lower rpms. As some of you
> > may or may not know, as the intake valves open and close, the
> > charge accelorates and brakes like a slinky or traffic. Given a
> > certain desired resonance, when the valves open again, the air
> > waiting outside is a pressure wave and not a rarefied valley.
> > Longer intakes lower this resonance, shorter raise the resonant
> > frequency. The frequence of the pressure waves is rpm dependent.
> > Those Bose desktop radios with incredible bass response for the
> > speaker size use the same principle. I know that some companies
> > are experimenting with variable tuned intakes that change
> > resonance continuously with rpm.
> >
> > I was thinking of sticking with the stock air had but put a
> > solenoid driven butterfly valve that closes the entrance to the
> > chamber at higher rpms and see what happens. This should push
> > the resonance back up where the higher rpms can make use of it.
> >
> > Marty
> >
> >
> >
> >
> >
This archive was generated by hypermail 2b29 : Fri Jun 20 2003 - 11:54:40 EDT