[eric tx20]

how do the drew shotguns compare to header inserts on noise level, I run headers dry on a 565, last day out I took inserts out and picked up 4 mph, would like to try shotguns but if it is a lot louder I may not be able to use them. they tell me its pretty loud but none of the law around here have a decibal meter yet

 

[GT Jets]

Back in the day I believe the Shotguns were only worth about 12 dba at best, with water I think you could get them to take out up to 15 dba. Both ways they have little effect on HP.

The newer ones are somewhat improved, but have not seen them used, I like the idea of the ones with the insert, but again, have not tried them. I would imagine the HP would be affected more with the newer design unless someone came up with a way to get something for nothing.... Unsure

Wish I was more help...

On a side note, the tap tap tappitty tap will make you slightly insane at idle... :lalala:

 

[mpkardell]

how do the drew shotguns compare to header inserts on noise level, I run headers dry on a 565, last day out I took inserts out and picked up 4 mph, would like to try shotguns but if it is a lot louder I may not be able to use them. they tell me its pretty loud but none of the law around here have a decibal meter yet

FWIW: Link described what I ended up with after years of experimentation.

http://www.performanceboats.com/jet...tage1-mufflers-free-me-law-4.html#post1715714

Well - a link it's not. Copy & paste.

Also, I didn't mention that I added some stainless steel disks/weights to the Shotgun flappers to dampen the oscillations at idle (and help keep them from clicking).