Mr Helmholz - simple model

[Pat Ford]

I was thinking ( rare but it does happen) when a standing wave is set up
the exhaust would be moving slowwer (higher pressure).

where the standing wave was there would be more of a heat buildup
 due to a slightly longer time in contact with the pipe.

the standing wave would be related to the Helmholz model ( the wave could 
 be caused by resonanse(sp?)

so tying the two hotspots on the two  collectors should help? by 
 transffering the presure peaks between the 2

does that make any sense?

I don't know how it works the the local engine guru in Kingston swears 
by it.

Previously, you (Todd....!!) wrote:
> 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...
> 
> 

--
Pat Ford                           email: pford at qnx.com
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