unless you cat some itr/ctr cams and a s2 Intake manifold, im pretty sure you will LOSE power. this is b/c gs-r's have a dual stage intake manifold. at about 4400 rpm vtec is engaged but air is flowing through the longer, thinner runners in the intake manifold. this is for velocity. at about 5700 rpm, the secondaries in the gs-r intake manifold open up allowing more air into the engine via the shorter, fatter runners. if you convert to the itr ecu, your vtec wont even turn on until 5700 rpm's and i think that your secondaries won't ever open, although I could be wrong about that part. (not sure if secondaries are ecu controlled) hope that helps out some. peace