Is your car much improved over stock?
If so, be happy and don't worry about chasing numbers. They aren't all that important.
If you weren't able to dyno it before the mods, most of these cars stock will baseline in the 280-290 RWHP range, give or take a bit. What you're concerned with is improvement gains over the previous state your car was in.
Same setup on different dynos and different days can give you different figures.
How your car performs in the real world is what counts.
things are not as they appear to be.........
2009.5 LiquidRed/OnyxRed, Premium Package
e85 Surprise Package