The idea was to get a greater volume of air into the airbox at high speed to increase peak power.
Whilst at 120+mph they do this - the overall pressure (which is what they wanted to increase) didn't change - well not until the filled the frame rails with expanding foam. Kawasaki make the frame open for a couple of reasons - the first is obviously weight, second is ease of manufacture, thirdly the route to the airbox is through the frame - it doesn't matter what you do with the airbox - if you don't make the route from the front to the stacks a sealed system then you will never increase the pressure beyond a certain point. Vivaldi ended up filling the frame rails. MSS, Hawk and PSG-1 didn't and made as much bhp but more importantly more torque. What they did do was change the internal structure of the airbox slightly rather than removing the lid and using the tank as the lid (which they found never sealed properly due to the anti-vibration rubbers, removing them made the alloy tanks crack).
Hawk and PSG-1 made a two piece carbon airbox with a quick release top. This kept the pressure the same and increased airspeed into the throttle bodies. It also used the standard air filter shape so race versions were easily available rather than having to make one off's.
They look good but give Rob a call at RJS and ask him just how much work it REALLY takes to get one working anywhere near properly. Kit ECU, sensors, brackets, etc that unless you happen to have access to a complete Vivaldi bike is basically guesswork nowadays. There aren't any diagrams, parts fische, etc.
They made it up as they went along testing, racing then binned them afterwards and went to Suzuki!!
I did have 3 full bikes in my possession at one point and about £500k of parts and even then all 3 bikes were different despite coming straight from Vivaldi!!
They're a talking point to have - just don't expect BSB spec power on the road - or decent throttle response either for that matter.
