Upgrading a stock Subaru Impreza WRX?!?

performance:

springs, or full coil-overs if you're willing spend money(as lowering springs deteriorate stock struts within year or so). larger diameter swaybars huge plus, , tires , rims lot car. 17-18" rims falken azenis 615s make car stick road glue.

if azenis 615s careful because in other dry pavement, pretty unstable. on wet/rainy roads began lose confidence in them. , 615s wont last more 10k miles, amazing tires, , cheap boot. switched falken ziex-512s , not quite sticky 615s last lot longer.

of stuff make car handle better, go there first.

power:

intake, exhaust , ecu mod(considered stage 2) more enough now.

intake: not, repeat not other spt or cobb short ram intakes. our cars finiky intakes work maf sensor. other short ram, silicone hosing turbo, intercooler help, not significantly. manifold not need changed, nor turbo(for now).

exhaust: not new exhaust header, complete waste of money our stock header has been proven flow cars running 500-600hp. if want cheap catless up-pipe, used sti up-pipe. catless , bolt right in, , can pick 1 $60-75. there lot of downpipes out on market our cars, cobb, stromung, invidia make downpipes, research , see work best want. catalytic converter, there no need spew garbage atmosphere breathing 5 more hp. midpipes , axelbacks you, see sounds best , go it.

ecu: there lot of ecu options out there our cars... personal recomendation cobb accessport. easiest , best. along easy changing/updating of engine maps, have handy features boost gauge, voltage monitoring, rpm, valet mode, economy mode , host of other things. expensive, wont require more tuning , unless going go crazy car, work great you.

couple other notes:

research! invested 5 months of exhaust listening before bought mine, , worth it! every part buy, dont crazy first thing see.

take care of car! if you're going push hard, treat right. run gas in it(chevron, shell) always! put best engine , gear oil in it, full synthetic mobil 1, amsoil or royal purple.

, huge note:

tranny very fragile, if you're going pushing more power through , putting more stress on it. don't launch car. trust me, i'm on second tranny , not fun thing change, not mention costly if you're not going yourself. have seen more handful of people blow wrxs gears peices. if you're serious ragging on car time, think getting straight-cut gears or full sti drivetrain(~$6000). tranny first thing fail if abuse car.

luck! enjoy suby!

i've got 2003 subaru impreza wrx , wondering next steps improving hp , performance? information helpful!

Cars & Transportation Car Makes Subaru Next