View Full Version : exhaust

10-13-2013, 04:41 PM
hi guys, i have a 16 donzi with 302 . my question , what options do i have for switchable exhaust or mufflers

10-13-2013, 05:32 PM
Sounds like you have through transom exhaust, if you have center risers you should not have any issues going either route. Switchable will cost a bit more than mufflers but give you the option, mufflers need to be removed for more noise. I went with external mufflers due to header clearance.


10-13-2013, 11:22 PM
Need to know more on what your setup is year , drive , pics of the risers and back of motor

10-14-2013, 05:58 PM
Very happy with my Corsa Captain's Call...

10-15-2013, 10:07 AM
options for silent choice

basic parts needed are center risers as MOP said , diverters, y pipe and possibly an exhaust bellows for the drive not sure on your OMC setup.

then you need to make it fit if there is no off the shelf system for the OMC. I am not sure if they offered it as an option. you'll need to make sure there is room for the diverter between the riser and transom and that it will meet the y pipe

I had a corsa system on my 1968 ford /volvo aq classic this was the only one I'd ever seen on an old ford volvo aq boat.

basically the system was a modified cut down volvo y pipe, corsa diverters, and a creative hose connecting system.

the system was 3 inch in 3 inch down and 4 inch out so the tips needed to be changed. The y pipe may need to be cut down.

here are a few pics of my old setup to give you and idea I removed it and went staright thru hull.

options for mufflers are abundant some of the Lake George guys have installed the ash can type tips and like the sound and LGPC likes the levels. other have used the slip in and like them too.

some other thoughts


if the y pipe needs to be modified will the flapper system in the pipe be effected.

will the system have enough back pressure to avoid reversion

exhaust exit angle

some people like the mechanical type diverters where they operate mechanically from open to closed over the electrically controlled open or closed system. this way they can have a partially closed system that lets them cheat on testing.

I have considered re installing my corsa system , with the benchseat you are closer to the noise than my 16, so conversations at idle are kind of hard to hear .

BUT Conversation is way over rated ;)

10-15-2013, 11:20 AM
Another +1 for Corsa diverters. I have a custom set in the bowrider that they fabbed up based on my pictures and measurements. Really great company to deal with and the hardware and fabrication is all top notch. They have downloadable forms on their website that outline what measurements they need. Installation took two guys, a full afternoon, and a case of beer. Whacking 4" holes in the back of the boat is a little intense... It's amazing that there is more real estate to plumb the exhaust in a 16 vs. my 21' LXR.

If you've already got holes in the transom that might make it a little more difficult, or at least require some very precise measuring to get everything lined up. In big boats you can cheat a little with the rubber or silicone exhaust couplers and get a 1/4" of flex here or there. With small boats like ours there is very very little margin for error. There is literally less than 1/2" total between the end of the riser and the diverter and the diverter to the thru-hull tip on my installation.

As far as mufflers go there are "slip in" baffles that fit in your tips if they're long enough, but I don't think they're very effective. I'm running the coffee can sized Corsa bolt-ons to quiet her down on some of the lakes around here. Easy enough to take off and let her honk for the Gorge Run...

Blind Horse
10-15-2013, 01:35 PM
I was also concerned about reversion when installing the 383 400 black scorpion in my 18. I have corsa quick and quiet plus (switchable diverters with silencer tips). When I called Corsa, they were very knowlegeable about the backpressure i could expect with various exhaust/engine configurations. You could consider calling Demian Szust at Corsa (440) 260-3136 or dszust@corsaperformance.com if you are concerned about reversion, it is a really important thing to get right. So far his recommendations have been spot on for me and my 383 has not ingested water, yet....

I have been happy with the quality of the Corsa products but I haven't used any of the other brands either.

Jeff Vander Yacht
Bellingham, Washington

2001 Classic 18

10-16-2013, 08:01 AM
one more thought not sure if it is the case on your classic but OMC did some strange things with the exhaust exits on their classics some are in the standard area but some are not I have seen them very wide and low ( close to the waterline stripe on the transon near the chine) on a few OMC boats. that would need some special plumbing