Just over 100db's? That's LOUD! You mean just over 90db's? Laguna normally has a 92db limit... or were you running on a race weekend?
Agreed...I also have 2bular GT3 8x24 with 2bular decat - don't need a tune with this. I also have ported header - again don't need tune.
If you go with just 2bular exhaust, it's relatively quiet (just over 100 dbl - when you are WOT - at least, that's what Laguna sound checked me at).
I have Charlie tune with BWR setup.
Nice thing about Jim's 2bulars is that he sets up the exhaust for s/c - just let him know in advance.