[Mgs] MGB exhaust system.

[PaulHunt73]

On a chrome bumper the tail pipe is straight so you should be able shove a 
broom-handle through the rear box (or not) to see.

I suspect there are many variations. I vaguely recall reading one box may 
have been baffled to reduce one type of noise by slowing down and smoothing 
out the pulses, and the other straight-through with perforated pipe to 
reduce high-frequencies.  Since partially crushing my middle box 
significantly improved the sound, I rather think that is baffled, the rear 
is definitely straight-through.  That's not an 'original' though (how many 
are today?) but an SS 'direct' replacement.

The baffled box generates some back-pressure which performance boys don't 
like, so go for straight through, but I suspect that is a case of 'Never 
mind the effect on bhp, listen to the noise'.  Go too far in reducing 
back-pressure/increasing flow and engine performance drops off.

PaulH.

----- Original Message ----- 
> Does anyone know how the original mufflers were constructed.  Were they 
> internally baffled or were they a fiberglass packed flow through design? 
> It seems all of the information I can find indicates they were of the flow 
> through design.