Theo Smit wrote:
> Reading through a car magazine (that shall remain nameless), I came across an
>ad
> for an exhaust company making "synchronized crossover H-pipes" for late model
> Mustangs.
> So, has anyone seen or used these? I know this would be hard to do under a
> Tiger, but that doesn't mean that one shouldn't try or at least think about
>it.
>
> Theo Smit
Theo, and Tigers,
I have some experience with "H" pipes. The Ford Mustang, in their GT and other
dual exhaust options, as well as the Shelby versions, all used "H" cross-over
pipes
as standard. The later model mustangs, being stuck with emissions rules, have
been
unable to use dual catalysts for cost and emission performance reasons, so such
changes, unless done by the factory and certified, are not legal. That's why
you
see after market kits that are probably marked "off road use only", like sure.
The exhaust note is much smoother and sounds better. Loudness still depends
upon
the muffler and the exhaust pipe diameter, just like an organ. There is an
increase in performance as the crossover only exchanges gases when there are
different pressures between the two sides. A good header set is designed to
help
extract exhaust from adjacent cylinders by 'length tuning' for these low
pressure
pulses to help 'suck' the gas from the higher pressure pipes.
In the tuned headers, this is tuned for specific RPM range, again these waves
are
acoustic pulses, and the 'spacing' changes with rpm. So it works really well,
over
a narrow range.
The "H" pipe is similar, but not so effective, and has the same attribute of a
narrow range of maximum efficiency. Their claim of being better than others is
probably substantiated by the fact that most stock systems doesn't have any.
While it would be of marginal help in a Tiger, and improve the smoothness and
resonance of the exhaust note, it will complicate your life enormously if you
have
to do any repair. I built a set in my Hand Crafted Sports Car for the V-6 by
using
two hole compression flanges and short stubs on each pipe, with a removable
center
of the "H". It works fine.
A two inch exhaust, and a good choice of mufflers will change your exhaust too,
until your wife, neighbors, or Allan's friendly off duty cop take notice. {9->
Steve
--
Steve Laifman < Find out what is most >
B9472289 < important in your life >
< and don't let it get away!>
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