If it helps, i too was worried about my first trackday and the noise of the bike, mine was a trackday at Oulton, at 102Db, i borrowed a noise tester off Paul (CRM) and got loads of different readings, but to be honest you need it testing at the circuit as there are so many variables that effect it.

NOTE, i still have your noise tester Paul, i'd totally forgot about it till the other day, PM me you address and i'llget it sent back.

As my bike runs a full race micron system, I was a bit panicky about noise and didnt want to waste any money either, so i took the can off took it apart removed all the old packing from it, wrapped some stainless steel wool round the baffle and then re packed all the exhaust, it only took an hour or so and the S/S wire woll was off ebay for a couple of £££, definately not more than a £10 delv.

I also bought a Db killer from gaybay and put that in.

So the big day came and i got the bike nice and warm in the testing queue, and basically hoped for the best, they tested it at 89Db and i think (it is only think mind) that Oulton are pretty strict and people who test elsewhere under 102 tend to test over 102 at Oulton.

I think you'll be ok with a bit of prep work, but a Db killer alone should have you right.

I have a stubby yoshi end can and with a Db killer fitted it makes about 101Db thats tested at Cadwell /Rockingham on the NC30. Unfortunately its at about 8000 rpm which is just where it seems to make the most noise.