This the guts of a stock SE slip-on. I removed the fiberglass, drilled 1/2 hole in cat and 5 extra holes in the smashed down part of the baffle. Sounds and feels better.



This what the fiberglass looks like, almost overlooked it.

 

How can you drill half a hole? ;-)

 

there is no such thing a half a hole once you make a dent or divot it's a hole.

 

Thanks.

 

That fibreglass makes quite a difference to sound and power. You can also cut the baffles in half, just where that scoooped-in bit starts, just before the holes (or just after, depending on which end you are looking from).