[Vwdiesel] Fish-tail

[Mark Shepherd]

Greetings all.
Just renewed my exhaust on my QuantumTD waggon. Cleverly, both the waggon and the sedan need a 6" extension piece to allow for being 5" longer than the fastback. 

I am just going to wedge apiece of old exhaust onto the end of the muffler, however I seem to remember being able to change the sound of the exhaust in the 1970's and earlier with fish-tails etc. 

Anyone remember the theory of squeezing the end, other than the need for back pressure for gassers? 

My old 'Q' with an Audi engine had a pleasent rumble... What makes a rumble ?

Mark