dyno dynamics dyno's read WAY different than the more common Dynojet.

so that 240whp on that DD is more like 280-290 whp on a Dynojet.

As far as what you're boosting, in my LS, my 18G would hit 8 psi by 3400rpm, even with the 2" elbow and 2" downpipe, HF cat, 2.25" exhaust. so, 14 psi doesnt seem to far out of the norm.

also, 14 psi is about double what that greddy wastegate is designed for anyway, so you're probably just leaking boost through there. You're probably just spinning the thing too hard, and it cant keep up with the extra air.

thats my two cents, even though i could be wrong.

lets do some math.

14.7 psi for atmosphere + 14psi that you're boosting = 28.7 psi. so lets just say you're making 275whp on a dynojet. 275whp / 28.7 psi = 9.58 whp per psi. 14.7 psi x 9.58 whp = 140.8 whp if you were N/A. sounds about right. so if you boost 10 psi, thats 24.7 psi x 9.58whp = 236.26whp. play with the numbers. i really dont think you're far off.