[TR] Car Harmonics

[Dave1massey at cs.com]

In a message dated 10/19/2009 9:56:11 PM Central Daylight Time, 
pdonnel1 at san.rr.com writes: 
> Does your Triumph have a harmonic? What I mean by that is . is there a 
> rpm
> that your car seems to get quiet? Where it just seems to hum along. The
> muffler resonates right, the engine purrs, the drive train is in total
> balance? Mine gets "in balance" around 4000 rpm.
> 
Car companies spend millions turning out resonance's in modern autos.  But 
I think most of the racket comes from the exhaust system.  The Falcon system 
on my TR6 is particularly bad.  I don't think it is so much the noise 
coming out of the pipe as it is the walls of the muffler vibrating.  The mild 
steel mufflers are made with heavier gauge steel and don't resonate as much but 
the Falcon designers decided that since Stainless doesn't rust they can get 
away with thinner material.  They were right and the muffler has lasted 13 
years but the down side is I will probably replace it for other reasons.  
But that is a round tuit yet to be got.

Dave