Mr Helmholz - simple model

[Todd....!!]

Never heard that one, will check with some other buds and see if this is
a true tuning trick!

Sounds logical to me... Now then, where'd I put that Helmholz model so I
can test this theory, lol...

BTW, since we're on the subject of exhaust and tunin it, have any of
you's heard of a crossover BOX?  I believe I heard a Stang with one, it
sounded TOTALLY FUTURISTIC!!  I've NEVER heard a car sound like that... 

It sounded like a car would sound if it were on TV in the year 2030 or
so...

I wanna try n make my Bee sound that wired, that is, if it's efficient n
all...

Thanks again for the tidbit about the crossover tunin!

Todd....!!
-------------

Ord Millar wrote:
> 
> I have heard exactly the same for an H-Pipe.  Paint it, and where the paint
> has blistered up is where the crossover needs to go.
> 
> -----Original Message-----
> From: Todd....!! <atc347 at c-com.net>
> To: diy_efi at efi332.eng.ohio-state.edu <diy_efi at efi332.eng.ohio-state.edu>
> Date: Wednesday, May 19, 1999 6:20 PM
> Subject: Re: Mr Helmholz - simple model
> 
> >The way I was taught to roughly but effectively 'tune' my exhaust system
> >on my 4 stroke v-8's engine's is to bolt about a 2 or 3 foot pipe to the
> >header collector paint it black with some spray paint (preferably BEFORE
> >installing the pipe) then do a run down the strip...
> >
> >After runnin the car at WOT for a 1/4, there will be a point on the
> >'tuning' pipe where the paint has been burned off, and a point further
> >up towards the header where the paint isn't burnt at all!
> >
> >At the point where the paint begins being burnt is where ya cut the
> >pipe.. Whalaa instantly tuned exhaust...
> >
> >I've never heard a technical explanation of why this works or even if it
> >helps or hurts or is just a guess at the correct length of exhaust
> >pipe...