Ideas

could try with a simple k+n air filter, increases power and air flow into engine, only costs maximum of £80, or you could try a 1.6 corsa throttle body, just increase everything that gets combusted. Or, if your budget is a few hundred pounds, a quick ecu upgrade could do the job for you. If you fancied, you could also buy a 4-2-1 manifold and straight through exhaust system, but then you're talking big £££'s

Best thing to do is simple, although the gains will not necessarily be the gains you looking for. * Do a full "PERFORMANCE" exhuast * Air filter (K&N / BMC) * Throttle body (not going to see any improvements unless you go ITB's) * Gas flowed head * Remap the ECU All of this will set you back a bit and your gain will be anything from 10 - 15 KW @ the fly unless you go ITB's then you will get substantially more although you will then need to have a piggy back chip fitted. ITB's can give you up to 50KW dependant on what ITB's you have and other mods made to your car.

Oh yes..... Remember a free flow is not a performance exhaust!