Hi,
If you are going for speed..
1) Daily or track only?
-A track car is NOT for daily ride. So if you want to make your car a daily ride..read on..
2) How Fast you want to go?
-180/220/240/260/280kmh? Remember the faster you go.. the more you have to spend on the next no 3 and 4..please put in mind a wira dont have ABS, stability control, traction control and all other high end things..When a 5 series BMW whack a corner.. please don't act the same by tailgating it..
3) Car safety aspect
-Higher performance car demands better parts in terms of quality. Twin pot, good brake pads, reliable abs, performance bushing, Hi performance tyre, good rims..and the list goes on..
4) Engine reliability
- More power means more things to upgrade..cam, piston, bearings, upgrade air intake, better exhaust flow, programmable ECU and the list goes on..
4) Long term maintenance
-High performance car needs higher maintenance..Cant use cheap engine oil, racing spec engine oil and gearbox oil is almost a must.. wear and tear things..cant use cheap tyre..cheap brake pads..
*So, personally i suggest to change your gearbox to manual..upgrade air intake (please don't use imitation), upgrade extractor and piping + muffler, get a sport clutch, upgrade braking system, make your car weight less (use fiber hood etc), good adjustables and lower ur car height, hi performance tyres and light rims. You should at least feel noticeable difference. This all already cost you nearly RM10k..And if you still have some dough left... go for hi cams and ECU :)
What Izso comment is right.. u might go for engine swap.. but still need to upgrade ur car handling and safety...