[scoubidou]

You have the perfect setup for an IMAC plane and the BMB canisters are tuned for big load and low noise. If you're goal is making noise then:

1) Replace 3 blades prop by 2 blades to let the engine turns the prop over 6000 RPM like Menz 30x12 0r 32x10 or other small wooden props.

2) Replace the cans by Bolt on Pitt mufflers.
Daniel