well....i started with a half inch hole. I rode it one day...about 20-25 miles. After hearing Ken's before with one inch hole, i knew i wanted a bid deeper and throatier sound...and therefore, would need a bit bigger hole. Then i went to 7/8 hole...so i could use half inch conduit plug to fill it. It sounded QUITE A BIT BETTER...than the half inch hole. But finally, i decided maybe i could even go a bit more. So JUST TODAY...i enlarged with a vari bit from 7/8 to 1 1/8. 3/4 inch conduit plugs just do fit the 1 1/8. Hole. Now it sounds EVEN COOLER....a bit more louder...a bit more deeper/throatier. But i'll admit, i would NOT want it any louder on the road on a long ride. Around town...it is PERFECT. SOunds really cool.
But on a long trip...it might be a bit much. one inch is probably the PERFECT size for sound...for me. But then, i could not have plugged the hole with a conduit plug. So i went to the 1 1/8. i like it...just don't want it any louder.
That said, i'll probably NEVER put those conduit plugs in. it just sounds too cool. ALso, i rode it 85 miles today after drilling...and i noticed with 1 1/8 hole...it is harder to get it to 'pop' if you get on the throttle hard and then back off quickly.....which sometimes makes it 'pop' or slightly backfire after the mod...at certain RPMSs....as i noted here before. WIth 1 1/8 hole, it almost never does that (just to reiterate....this only happens if you grap a fist full of throttle...crank it hard....then slam the throttle shut....and then, only at a certain RPM range...and not every time...so it aint no big deal). 7/8 sounds pretty good. 1 or 1 1/8 better. anything more would be too much on the hiway for me with my windvest and half helmet on.
oh yea, i took it up to 125....couldn't see any difference in performance. and the wife and i swapped off back and forth on her non drilled Rune...just to compare. other than sound, i saw NO .....ZERO difference in performance. Just that hers sounds pretty lame to me now :wink:
She said mine sounded cool riding it...but it is too much sound for her. but then, she doesn't like pipe mods...period. i like having one bike modified...one not modified...to be able to 'actively' compare between them for reference.