as others have said do it properly, run a 4" dump or at least a 3" split dump. you dont want to get to tuning time and they say that all the money you spent is a waste cause you were a tight arse with your exhaust
I have a bf tornado, I managed a 13.6 stock standard. I now have 3.5"exhaust, injectors, pw cooler. 300kw and I ran 12.4 they dont need much to get them moving along. a 12 second street car is still pretty fast
im 21. bf 11 tornado also had a turbo vy ss befor and a ca18 datsun 1200 ute. when I got the f6 thought it was slow. but recently had a new exhaust, injectors pump and cooler and got 308rwkw so its a bit quiker now