more on mufflers

["Bruce Hevner" <scramblr@xxxxxxxxxxx>]

>When one tests mufflers, can you be sure that  the flow with hot, pulsing
exhaust gas will be the same as a cool, steady flow of air? Or at least
>comparable from one muffler to another?

 

>No it isn't the same, but at least it gives you a point of reference.  The
exact same question could be asked of Cylinder head flow testing (but rarely
is!). 

 

In fact that question HAS been asked has been asked a LONG time ago. I
remember reading about a racer that took a LOT of time and a LOT of $$ to
set up a working valve train to test on his flow bench. I think it ended up
as an exercise in futility and if you'll notice none (that I know of) flow
bench mfgs recommended trying this. It's more important to use the bench as
a measure of change than absolute flow numbers. How much are you improving
is the first order of business, flow numbers second.

Bruce Hevner