No 7" wide will not change your class. Especially in the STU / STX class.
Hmm ... since you still have a Cat ... I thought you can still stay in the standard ST class ... Battling in STX/STU in our region is like suicide. Crazy mods on the cars in this class and very good drivers. ST is more of a mixture and you can have fun and be competitive.
Back to your original question: I vote new tires as oppose to new wheels. Wheels are nice but the tires are the real kicker for better traction and runs. ... then later save up for stiffer suspension. The SVT suspension is still too soft for the transitions around corners.
Hatch Nation Member: #147
R.I.P - FELLOW FF MEMBER, IZZY, BLK2k3GTS, will always be remembered. We will compete on a different course again one day.