I tuned a Pro Street car (more like a Pro Fairgrounds car) that had a blower with a hat with sixteen injectors in the hat. It was all looks and not much performance since the combination was way too squirrly to drive. But we did get it to start and idle so he could drive it around at the car shows. The guy had a ton of money in that car and it was barely useable.

The big problem with using a hat as your throttle body is that hats aren't designed to be very precise. Throttle bodies are machined to very precise dimensions so you can control the airflow and maintain a steady idle. Hats are just cobbled together drag race parts. When you use a drag race hat as a throttle body you have a very difficult time controlling the idle speed. It ends up being kind of a joke of a system for a street car, works okay on a drag race car with a high stall converter.