I have searched several times and most of the results are for people making big HP and not wanting to lose any of it. I am only making like 330hp, so its not as big of a concern to me

What is a concern is price and effectiveness. I want a muffler that quiets the boat down a good bit. I just moved and where I used to boat my straight pipes were no problem, but I imagine here they will be...

Any recommendations??

I have also noticed when looking at mufflers most seem to advertise 10-12db drop. I dont know much about db and how loud what is, but that just doesnt seem like much?? correct me if I am wrong...

Aqua Power Ltd. - Florida. They make a great working stainless muffler that does not seem to have any power losses and much better db noise control than most I have seen and heard.

Best Regards,
Ray @ Raylar

10 db is a lot. When the noise is reduced by 3 db the sound pressure is cut in half so it sounds like you turned off one enine of two that were running. So 3 db is half the noise, 6 db is 1/4, 9 db is 1/8 and as luck would have it 10 db is 1/10th the noise. The problem is your ear and a db meter may not agree with each other because they use A-weighting on the meter. That's story all by itself.

I installed these on a customers boat with a HP500 EFI
[ATTACH=CONFIG]506714[/ATTACH]
You can read more about them here
Also available from Summit Racing

i have Gibson slip on mufflers that help A LOT with the noise. in fact my wife will only go riding if they are on. BUT my htm ss24 with a n/a 565 will run 100.5- 101mph without mufflers and only 98mph on gps with the mufflers. not sure how much hp loss but its noticeable. boat is very consistant and this happens every time.

There is also GCB Exhaust Technologies out of Ontario. http://ggb.ca/index.php?id_category=...oller=category