03 cobra not making BOOST

Well I got her dynotuned via an SCT chip and she made 460hp and 489tq to the wheels. The blower is being overspun after 6000 rpm due to the 2.8 pulley. The dynograph starts looking like a gradual sinusoidal wave after 6000 rpm. The car feels alot better now with the tune and it picked up 22 foot pounds of torque. What numbers should this thing run if I drive it right? My best 60' is 1.85........ By the way thanks for the input