Offshoreonly.com - Muffled exhaust concept

Offshoreonly.com (https://www.offshoreonly.com/forums/)

- General Q & A (https://www.offshoreonly.com/forums/general-q-20/)

- - Muffled exhaust concept (https://www.offshoreonly.com/forums/general-q/57048-muffled-exhaust-concept.html)

Muffled exhaust concept

I spoke with both CMI and Corsa yesterday about converting my captains call diverters with no mufflers into some sort of muffled option. In the end they both suggested a similar concept. It looks like I will replace the switchable diverters to an open Y pipe and replace the tips with muffler tips. The concept here is that at idle I'll be quiet, but at higher RPM's where the muffled tips start to restrict the extra back pressure will feed through the down pipe with little or no restriction. Both claim I should not lose any speed with this set-up. Sounds like a winner to me, has anyone tried this? Corsa calls it "Quick and Qiet II", CMI has no name for it as the have just begun to get into the game. My engine is a 496 Mag HO, and my plan is to upgrade to the tips they make for the HP 500/525 just so I can do some upgrades if I want to.

BTW, both said I will lose top end if I just add muffled tips and continue to try and divert all the exhaust out the back.

So I have a near new Corsa Captains Call system for sale with tips if anyone is interested. Only 25 hours and it is the chrome version.

If you have a y-pipe connected to the captains call you have a triple exhaust system now. The Captains Call runs exhaust through the Y pipe and out of the prop at all speeds. It doesn't shut off the exhaust "through the prop" when it is going out through the transom. Just add muffler tips to the Captains Call!
Make any sense?
Sincerely
Dennis Moore

I to would just add CMIs baffled tip to your existing Y valves.

How big is is the butterfly valve in the Y pipe I have? I assumed when it opened it would semi-close the lower outlet. If this is the case I wonder why a guy I run with lost some top end when he re-installed the Corsa muffler tips that came with his new Baja. He has the same Captains Call but had taken the mufflers off before he even ran the boat and went with open tips. His engine is also a 496 Mag HO. I guess that why I'll go with the tips designed for the HP engines not those desihned for the 496. Mybe those are jsut too restrictive. Thanks for the replies.