Well I put it on a tank without changing anything else today and there was a reduction of sound but not as much as I would like. I think there is too much pipe prior to the silencer unit. But was still a good improvement. The key to these babies is to get as close to the bulkhead as possible. They sell ones made from 3/4" at lowes that are just straight tubing bent into shape. I may try to do that with scrap material and see how well it goes too.
Just got a new idea, but it on the inside attached to bulkhead, let me try one that way and see how it goes
Just got a new idea, but it on the inside attached to bulkhead