Turbos setups are a skill that many miss. Hot side piping size, cold side piping size, routing, manifold/header design, intercooler size/design, turbo sizing, turbo placement, and even wastegate size/placement can make a turbo setup good, or shit, and i see many shit. One of the bigger issues i see, is people using low cost stuff, which yes works, but is low on the efficiency range, and spool also suffers. Now with that, you'll never get it to feel like a twin screw style blower, there will always be a delay from throttle mash to boost with turbos. 650whp is pretty easy, for even smaller twin setups, like a pair of 55-58mm's, which should keep spool very quick, and hit the torque curve right too. Many times, turbos setups make less torque, just cause they dont starting making boost till they are coming out of it. A properly done turbo kit, should make the same, if not more torque then a 2.3 at the same boost.