Has anyone tried a Harley silencer? I don't know anything about them, but I've noticed a few with very small after market silencers that seem to run very quiet (for a lumpy vee twin).
In answer to the original question ... "a lot". My racing comet with Mk IIs and a short tuned 1 5/8" pipe (or was it 2"?) was off the scale on the noise meter in the 80s (and I didn't actually take it up to the right revs). Luckily it was VOC Cadwell and Jaqueline Bickerstaff had the meter, so I sneaked out. After that it was hard work keeping the power and losing the noise. I could never understand why some simillar sized bikes on open pipes were so much quieter than the Comet.
H
In answer to the original question ... "a lot". My racing comet with Mk IIs and a short tuned 1 5/8" pipe (or was it 2"?) was off the scale on the noise meter in the 80s (and I didn't actually take it up to the right revs). Luckily it was VOC Cadwell and Jaqueline Bickerstaff had the meter, so I sneaked out. After that it was hard work keeping the power and losing the noise. I could never understand why some simillar sized bikes on open pipes were so much quieter than the Comet.
H