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The shape of the throttle plate isn't going to get rid of pumping losses. Worrying about turbulent air "friction" issues during part throttle operation when flow is small is silly. Even if your intake was less restrictive, you'd still have to add more throttle plate in order to re-restrict the motor to maintain the necessary power output. There's some confusion about the origin of pumping loss.
Pumping loss is a result of the energy lost when air moves through the throttle plate, going from atmospheric pressure to a lower, state of vacuum. It's a bigger picture process, but that's where it comes from. It's like uncorking an air tank and letting it spill out into a low pressure surrounding. That energy is lost - not mechanically captured.
Take a mini-turbine of some design and put it at the throttle body and derrive mechanical energy from this pressure change. Then, you've recaptured your pumping loss.
Other choices include using lots of EGR (to reduce manifold vacuum without increasing fuel requirement) or a delayed intake valve closing - such that the manifold can be held at one atmosphere, and the cylinder will only partially charge due to "breathing back out" during the compression stroke.
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