What about this muffler mod? 346xp

[volvo2før]

Have a 346E-Tech with a non-cat muffler mounted. I have tried to modify it myself, but want some feedback on how i shall do it. I have drilled out a extra hole, about 11/16" x 7/16". You can se it through the spark screen how big the hole is, and the deflector is from a 288xp. I have left the stock outlet as it is. How far shall I go with the grinder? Would it be better to enlarge the holes more, or shall I block the stock one and just leave it with the new one on the side.? (Pics)


One more thing, will it gain some more extra power if I match-port the cylinder exhaust-outlet to fit the gaskets and the muffler? (Pics)

 

[old-cat]

Here's the way I do and they make really good power! 266xp deflector, exhaust port opened out to the heat shield size.

 

[volvo2før]

Thank's alot for the response

What is the size of your new side-mounted outlet? Do you reassemble the cylinder before you open the exhaust port/outlet?

 

[old-cat]

I make the muffler side hole oval like a football field, a little more than 3/8" wide about 3/4" long.