You may "say" you're joking, but it is probably true.
A while ago I was running ecu, stock turbo, 13psi, and usual mods. On my mechanic's dyno it made a solid 183rwkw and felt strong. A week later I went to a dyno day and it made 214rwkw (same fuel, etc). Now that was a joke, dynos are only good as a tunning tool. On dyno days it is good to compare your car to others, as they are all run on the same dyno, by the same driver, on the same day. That is the only time you can compare figures, otherwise a peak power comparison ain't shit.
The Mafia: So once you upgrade your turbo, take it to the same dyno and compare and evaluate the result, but don't be disappointed if you take it to another dyno and "mysteriously" loss 30rwkw.