exhaust noise = power
mine is 3", race cat and only the rear N1 muffler, almost completley straight through - its reasonably loud, but I love the sound of it, especially under a bridge or through a tunnel. It had the centre muffler section, but this was removed due to clearence issues getting into my car park at work.
Clint32 replaced the centre muffler section with straight through 3" and tucked the exhuast closer to the chassis
Been through bretho's etc, and under idle its reasonably quiet, no cops have ever looked twice at it. I'd say it would be very close to, or over the legal limit. Sets car alarms off in car parks sometimes
I'd say if you can put up with it, stick with the 3", and maybe get a resonator put in near the diff/cradle, as that will knock a few Db from it
I am thinking of putting the centre muffler back in, on long drives it can get a bit loud, so might whack it back in.
Try a resonator, you might loose a few rwkw, but thats the trade off for a bit quieter exhaust
Chris