LC Scooby

Just fitted a apexi RSM to my bug eye wrx and just wondered if anyone had a set on figures for the p-loss program on it, with a good guess at the weight of the car the ps figure just seems to high for the power of the car so I just need a guide as to how much to trim the figure on the the p-loss by to get a better result any help would be appreciated, although I should leave it really as when it peaks its around 350ps which is a good talking point down the pub. The car is modded and has dyno'd 300bhp by the previous owner