Well, you've hit on a sore spot with me. Unmuffled engines might gain
2-5 mph on top end, but at the expense of annoying most people at idle
speeds. Ironically, since the exhaust is aimed away from the offenders
cockpit, it is usually of little to no concern to them or their crew.

Most if not all of these boats can elect to install a diverter which
outputs the exhaust under water at low speeds, but for various reasons
(cost, reliability, desire to be a dickhead, etc) elect not to do so.

In the motorcyle world, I'll buy loud pipes save lives as a arguement,
even if its a weak one. In the boating world, with only a modest gain in
performance, I'm guessing some people just need to "compensate for water
shrinkage", but that's just my opinion.

BTW the the pooor idle performance you've observed is a sacrifice to get
higher RPM at top end through more radical valve timing.

Bob Dimond




In article , "Doug Kanter"
wrote:

Dave: No comments from the peanut gallery.

I'm using the term "speedboats" to describe boats which sound like they have
(and probably do have) a pair of 400+ cubic inch motors in the back? In
order to achieve their purpose (speed), is it absolutely necessary for them
to be as noisy as they are, or are they just designed that way, in the same
way some morons alter their motorcycles because "loud pipes save lives"?
And, when they're idling, why do they sound (and smell) as if the engines
are only firing on half their cylinders?