I wonder how effective a twin scroll turbo would be? Fabbing up the header pipes in order to pair the cylinder pulses to each side of the turbine inlet would be a royal pain, but the Porsche engines that use it make crazy power with minimal lag time. Hyundai's new direct-injected turbo four uses a twin scroll and is thumping 274hp from 2.0L (along with 269 ft/lb torque @ 4500) I know DI and quad valves contribute to those figures but it is a 75hp boost over the stock 2.4L DI engine. A good flowing custom intake manifold (like Chris posted) along with a properly plumbed twin scroll w/a2a IC would be real trans killer