Re: Thanks-Exhaust Info!

[jlandry@domain.elided (John A. Landry)]

In Linda Tripp's secret telephone recording, Monica and Steve Stegmann
<stegmann@domain.elided> were heard saying...

>Someday I'm gonna measure the backpressure on the glasspacks and the
>turbos.

Steve,

I know almost next to nothing about fluid dynamics except that I've *heard*
(don't remember where... maybe here on the Digest) that the surface friction
of a pipe is the single biggest factor the exhaust flow has to overcome.  On
that assumption, have you looked inside a glass pack lately?  All of those
little "scoops" or "fillets" stamped inside the inner tube look awfully rough
to me.  I really don't know and it doesn't matter to me.  I don't like the
sound of glass packs any more and that was my biggest factor in my muffler
choice.  However, were I to have wanted that sound, I would definitely have
shopped around because just like with turbo mufflers, all glasspacks aren't
equal.  When I was shopping for mufflers, I noticed many glasspacks have a
smaller inner core tube than the inlet or outlet.  This seems to be a common
practice with cheap mufflers... turbos included.  The better more expensive
ones feature an inner core that is the same size as the inlet and outlet.

I'll be the difference in back pressure between a good turbo style muffler and
a glasspack are so negligible, you'd have to have some pretty expensive
manometer to even come close to measuring it.  I mean, what sort of back
pressure does a good 2.5" exhaust system run... 1.5 to 2 psi?  Not worth
arguing about.

To each his own I say... but just make sure you guys by quality parts so you
won't be disappointed a couple of years down the road.

Take care,

John L.

PS: Did you get the Clevite book from Hoff?  When are you heading to the
desert?
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