as you already have a ported turbo.. Go for a 2.5"..if your only going up to .8 bar your not going to make loads of power.. With those mods mentioned above your really want to start looking to get it up to 1bar, so all you'll need then is an fcd and some sort of fuel control whether it's a fpr/safc/emb etc.. @ trd that's simply not true mate, there's loads of ep's running over 200bhp unforged on tracks with no problems what so ever, also you don't need larger injectors, the standard ones are fine up to around ~215-220 bhp