I don't think the Si has the electronic throttle, the lesser civics have it because the car runs the throttle butterfly open to eliminate pumping losses and relys on the cam adjustments for the air/fuel mix in the cylinders, that's how with 140hp it can get 44mpg on the highway. Think of it this way, it should respond really well to bolt ons with the better breathing design, and the Dbw really only takes control under cruising, the rest of the time it does what you want, like under acceleration.