Hi there you two...it's good to see some more GTS boys in the UK.....
Philip: 250bhp standard,0-100 depends on manual or auto...top speed 100mph until you cut the limiter...
...go for the exhaust and filter ..no huge gains, but feels more lively and sounds the bizz
....don't think about messing with the boost until you've fitted an ACCURATE boost gauge.....and you don't want to go over 10psi with the R33's ceramic turbo....not to be confused with the higher-boosting R32 GTS-t....
....and just scour the forums for gems of advice....
Have fun,
Jon.