like nathy said fatty the 1.8 aint a bad engine if ur just trying to up the power a little , had on in my old s2 and clearly saw the difference
the injectors in the k jet will eaisily cope with upping the power , theres fule pressure reg mods and a mod on the k jet itself , dont know the exact details but seen it done , theres also mapabble 5th injector set ups from the likes of msd ,
just consult a local tuner , they should eaisily steer u in the best direction muck ,
beef