Sean H

i will be down thursday night or friday morning... i will call ya when i get down.....

i just asked about the 5" as there seems to be more options for that than the big ole 6".... i think just going straight with the 5" and baffles (wet) would tone it down a little.... are dave's cmi's inserts or the inline muffler style?

Falcon

If you mean the external drop "s" pipes, I think they aren't a real answer. I was thinking of dropping them inside. I don't like the looks of the external mufflers, especially the large ones with valves. I would rather leave the back clean and exit low on the transom.

Sean H

for us cat owners, most of the external fixes don't work.....

KiloKat

Just noticed this post. As Scuba Steve mentioned above, I have been trying several new muffler combinations on the 36 and 46 Bacardi Silver boats. The 36 now has HPI external mufflers running into 12" long Gibson turndowns. Seems to work great. At idle, where the J2005 test is supposed to be taken, the exhaust is exiting underwater and the only noise that I can hear is the whine of the supercharger. According to people on shore, it also seems to help lower the noise level when cruising - probably because the exhaust is being directed down rather than straight back. Performance still seems to be OK. I'm sure there is a power loss but it really isn't noticeable and personally I'm willing to live with a little power loss in exchange for being able to cruise the lake. Boat still accelerates good - pulled very strong to 160+ before I pulled off after noticing some wave runners about a mile ahead. For the 46, I had Gibson make a custom set of external exhaust using their mufflers with turn downs. Haven't tried them yet but hope to after Ft. Meyers. Will advise.

44MTI

Dave is your O3 boat legal with just the HPI externals you ran last year.You ran it for me at the toad and it sounded pretty quiet, also did you only have the externals or was there something internal I didn't see. I am planning on coming up the next two weekends and would like to not get kick off. Thanks for the help.

KiloKat

I have sold the 40 but yes, it was legal. However, it had 18" long mufflers in the tailpipes before the transom and then a pair of HPI clamp-ons external. As stated above, I'm not sure of the total power loss but it still ran 163 turning out and 148 turning in so I guess everything is relative.

44MTI

WOW, there was a 15 mph diffference between turning out vs turning in.

44MTI

I have the CMI inline muffers, not sure of the length, between 12 and 18 inches as well as CMI clamp ons. It seems pretty tame with this set up and they didn't bother me last year. But I was just concerned that they seem to be a little more strict this year.

KiloKat

Exactly - on the particular 40 "classic" that I had. However, it was a handful turning out so I always ran it turning in. As you know, each boat is different with drive heights, drive location to tunnel, rocker in bottom, etc. But those were the exact numbers on my 40.

KiloKat

FYI - I originally ran the CMI clamp ons externally on the 40 but it wasn't nearly as quiet as with the external HPI's.