Coop,
Too get pressure in the chamber.
Take that long piece of 1/2 that comes out of the "T" on top
Cut it in half and pinch one end down so you have about a 1/4" opening. that will act kinda like a stinger.
Then just use a coupler to rejoin the pipes.
This should give you pressure and quiet the pipe as well

If you look at the ones the guy on ebay is making. he reduces the final exit down to 1/4" pipe I think
That would give you pressure as well

Good luck