Greg and everybody
No clue whether this is right from an engineering point of view, but I
can't resist:
Perhaps the loss of power could be in the tuning of the pipes. The
negative pressure of one exhaust wave pulls the next wave out, and so
on, thereby creating less backpressure at the cylinder, thereby creating
more horsepower. If the wave isn't there to pull, i.e. it's in another
pipe, the power is lost. Oboy, lots of variables here; diameter of
pipe, length of pipe vs. length of exhaust wave, etc. etc. ad infinitum.
Any engineers out there wanna comment?
-S.
Hutmacher, Greg wrote:
>
> Yeah, I read the same thing in the TR250/6 Comp Prep manual. On page 22, it
> states that "When the two tail pipe systems were fitted they always resulted
> in a power loss of at least 8 horsepower. These tests were conducted with
> full racing, fuel injected engines." That raised my eyebrows also because
> conventional wisdom for street racing was always to go with the two outlet
> system. I was wondering if Kastner's results were unique to the fact that
> they were running 2 ½ inch diameter pipes with NO mufflers at all on a full
> race, fuel injected engine. Perhaps a stage 2 street engine with mufflers
> would yield different results. Anybody know?
>
> ----------
> From: Scott Decker [SMTP:sdecker@bellsouth.net]
> Sent: Sunday, January 31, 1999 10:27 AM
> To: Triumphs List
> Subject: General exhaust question
>
> List:
>
> I was browsing thru the Competition Prep manual for the GT6 and
> found an
> interesting tidbit that I'd like to throw out for comment. Kastner
> states
> (basically) that making a dual exhaust exit cost his car about 6
> horsepower
> versus a single exhaust exit. I'm certainly not questioning the
> master, but
> is this normal? There are many dual exhaust systems available for
> the GT6,
> and they are in common use today on street and race cars. Surely
> I'm
> missing some basic exhaust knowledge here. I'm interested because I
> am
> about to purchase and install a street/race type exhaust system.
> Reply to
> the list or me personally.
>
> Thanks for all the good advice and comraderie in advance.
>
> Scott Decker
> 70 GT6+ KC79034L
> Braselton (Road Atlanta), GA
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