[Fot] Header primary lengths

[Joe Curry]

Shane, It appears that the most relevant statement in that article is the
first one "'There are many ideas about header pipe sizing".

Joe C.


----- Original Message ----- 
From: "SHANE Ingate" <hottr6 at hotmail.com>
To: <fot at autox.team.net>
Sent: Tuesday, January 02, 2007 1:45 PM
Subject: [Fot] Header primary lengths


> Amici,
>
> I'm really confused by "rules of thumbs" pertaining to
> header lengths.  E.g., in a recent 6-Pack article by Kai Radicke,
> he states that "..shorter equal-length primaries .. emphasise
> mid-range" viz. longer primaries.
>
> Yet, trolling through the Burns web site, I came across this
> "Reader's Digest Version" of exhaust tuning theory:
>
> http://www.burnsstainless.com/TechArticles/Theory/theory.html
>
> One thing that stands out in the article:
>
> 'There are many ideas about header pipe sizing. Usually the
> primary pipe sizing is related to exhaust valve and port size.
> Header pipe length is dependent on wave tuning (or lack of it).
> Typically, longer pipes tune for lower r.p.m. power and the
> shorter pipes favor high r.p.m. power".
>
> As Kas points out in his book(s), exhaust design can get
> very complex, but the opposing comments (iterated by
> many others) indicates that there are NO rules of thumb,
> that all designs have to be tested on the dyno, and that
> serendipity is your best friend.
>
> Shane Ingate, terminally confused in Maryland
>
> PS Happy New Year!