Ok, your numbers are rubbish. There is no way you are making 160whp with I/H/E and some tuning. Especially if you state that a stock STi on the dyno you are using is only making 226 stock which is very low reading (perhaps if you had a high-reading dyno, but that does not matter). Basically a stock 2.5RS in the best of worlds is making 110-120whp. You aren't making 40-50whp with those mods. No way. You WILL need cams, higher compression pistons and headwork at the minimum.
Raising the redline on your car will make zero difference. These cars fall flat after 6000 rpm. If you want to rev you need more cam and more headwork.
I call shenanigans on your dyno plots. Either you setup the dyno to give you the numbers you wanted to see OR you are just not being square.