I think a dyno session with custom map is around the $330-mark, and power runs from $55 (ie so at least you can make a call at the early stage to see if you want to proceed with the custom map).
With the spark arrestor, keep in mind now that I drilled mine to buggery to get the sound just right for my liking.
In terms of a louder pipe, within the first week of mine I had a person open their car door wide, then immediately pulled it back in as they heard me coming. I was prepared in any case, but it was good to see it in action. I am a big believer in the safety factor of louder pipes.
With the spark arrestor, keep in mind now that I drilled mine to buggery to get the sound just right for my liking.
In terms of a louder pipe, within the first week of mine I had a person open their car door wide, then immediately pulled it back in as they heard me coming. I was prepared in any case, but it was good to see it in action. I am a big believer in the safety factor of louder pipes.