Loud Exhaust? Now That's The Ticket!

While it's always nice to be noticed, I usually prefer to fly a little bit under the radar. My Formula's Silent Thunder swim platform has an integrated muffler system that uses water to muffle the sound of my boat's exhaust. Blackjack's 454 Magnum sounds fine as it is--enough rumble to know there's something decent underneath the swim pad, but not so loud that you can't talk to your passengers at idle. And it's plenty loud enough when we're up on plane.

Other guys like to hear a real healthy exhaust note, since they believe it adds to the feeling of high performance. And there are also other folks who like to let everyone know when they're coming...even when they're down the lake a mile away. To each his own, I say--until it becomes overkill, or is so obnoxious that people start wincing when you pull up to the dock at the local watering hole and they can't hear each other or the music playing at the bar.

The fact is, a lot of municipalities and law enforcement agencies are cracking down on boats that are too loud. Grand Haven, MI, for example, is just one town that has gained a reputation among performance boaters as being particularly unfriendly, and maybe a little too zealous in it's enforcement of the law. Different areas have different requirements, so it's important to know what noise decibel levels are acceptable and from what distances it is supposed to be measured. Boaters and manufacturers haven't been standing still. One of the easiest solutions is to port your exhaust underwater with some down-tubes; of course, everybody hates the look of this solution, but it's possible to set it up so it could be removed easily, if needed.

Last year, Mercruiser came up with an OEM solution, with X-haust, a fully integrated sterndrive exhaust noise reduction system. X-haust was developed primarily to bring the HP600 SCi and EU662 SCi sterndrive engine packages into compliance with some of the more stringent noise regulations, especially those of the European Union. Mercury says the muffler design flows exhaust through two separate chambers connected by three attenuator tubes before exiting the exhaust outlet at the bottom, reducing sound pressure waves without sacrificing engine power or performance. The transom-mounted muffler is completely submerged when the boat is at rest. Since it's introduction last year, I have heard little feedback about the system or its effectiveness, but that's no surprise, since I doubt there have been many takers in the U.S. market.

For those who are looking for an add-on solution, a number of options are available. Custom Marine's Sound Elimination Systems mufflers offer proven sound reduction technology that will allow most boaters to operate in areas where sound emissions are restricted. Designed to reduce sound emissions to levels as low as 85 decibels the mufflers are engineered to lower overall sound without restricting exhaust or creating unwanted backpressure, which can keep your high performance engine from running its best. Made from 304 series stainless steel, they can be installed on any exhaust system with tailpipes ranging from 4" to 6" in diameter.

Custom Marine also makes a "silent choice"-type system; External Sound Choice silencers allow the operator to muffle high decibel sound waves emitted through the exhaust with simply a flip of a switch and a butterfly valve system. For safety, they are pneumatically operated, eliminating the risk of electrical spark hazards. You can also find other manufacturers who offer similar systems.

Like everything, there's a time and a place for the display of epic brute power. Way out on the lake or ocean, in a race or poker run, or even the occasional loud rumble at dockside can be enjoyable - within reason. Using your smarts and a good exhaust control system can keep your passengers, fellow boaters and law enforcement officials happy. In the long run, your wallet will thank you, too.