"Excessive exhaust noise" - MoT failure point

not as such, no. ISTR the regulations at brooklands called for something
like an expansion chamber of 8x the volume of the engine, or something like
that, and fishtails on the tailpipe.

 

yeah, and that, too.

 

Just a postcript - finally got the MoT on Friday, Tax on Saturday and
got chance for a good blat[1] on Sunday up and down the A50.

The success story was to fit a short length of pipe in the back of the
cans with a blanked off end. The sides were then drilled with 49 1/4"
holes to equal the cross sectional area of the original 1 3/4" outlet.

Thanks for all the guidance along the way.

Chris D
[1] one baffle fell out (and was retrieved) on way back - I obviously
need to bolt the things in rather than allow a single self-tapper to
fall out