I wouldnt expect much of a gain in HP from the TB alone its more of an efficiency thing I suppose. Being that much larger it will flow better and ensure your sucking as much air in as possible. I would think there should be an improvement in throttle respose as well, something that is usually in the complaint column on the crossfire. Paired with a better intake is most likely where you would get the most out of it. I am getting ready to do it, I wish I had some way of measuring the difference myself (flow numbers would prob be more significant than HP) But I don't think dyno time for a ~100$ part is in the future for me. Maybe at a group meet or something, I'd really like to see the real numbers as well.