If you were wondering why the road going H2 needs such a massive set of cans on it perhaps the H2R can provide you with some perspective....
For perspective, GP proto's run around at 130 db's....Exhaust Sound
The exhaust sound level of the H2R at the time of factory shipment is 120 dB/A using Auto Cycle Union (ACU) guidelines. It is the owner’s responsibility to confirm that noise regulations of closed courses permit vehicles reaching this level of exhaust sound. Changes to the exhaust system may alter performance and sound level.