Exhaust Tips - Loud or Stealth?

[RedDog]

My ’98 502 MPI 22 Classic has Silent Choice exhaust plus the silenced/baffled Corsa exhaust tips. The exhaust note is a deep rumble but fairly quite compared to a straight thru tip. I like the loud sound of the straight thru tips but at the same time also like the more conservative/quieter Corsa tips for those relaxation and slow cruise times. All winter long I have flipped-flopped over wanting to change to the straight thru tips. Even today, after partially disassembling to see how easy this may be (it is easy), I decided not to change. I doubt any performance gain would be seen on my stock motor. So the question is, if you had a ride like this, what tip would you use?

Current tips -

http://www.donzi.net/photopost/data/500/408stern1.jpg

[gold-n-rod]

I think it depends on how the noise rules are enforced where you run. Just flipping the CC switch to closed doesn't work if the neighbors have called the water cops on you or they catch you in a drive-by.

If you are not running in a highly patrolled/enforced area, there's nothing sweeter than the unmuffled song of the big block Chevy (small block is a close second). :yes:

All my toys are loud!!!!!

Man: "Nice boat, what kind is it?"
Me, looking at watch: "It's two-thirty." :biggrin.:

goldnrod

[FJB20]

Tiz a Shame ---You Own a Beautiful Donzi on the Water and Get Stopped for Noise but You Can Sit on Your Porch and Have 6 Harleys Go By with Drag Pipes That Rattle Your Windows and Nothing is Done -- Leave the Boats Alone -- Go After the Real Noise

[MOP]

Have you thought of Super Traps, I have been thinking of trying to find ones that would slip over my exsisting through hulls and be held in place by a push button ball lock pin. My problem is not on the water as much as flushing in my yard, but may also prove handy at times. Nights leaving from dinner in our fav spot, plus I have a bud way up on a long creek that runs through a windy marsh flat, you can hear a fart a block away. So any noise and the Fuzz is called!

[Ed Donnelly]

My buddy has traps on his Scarab. We used 1/4 x41/2 bolts. Easy on,easy off. You should put deflectors on the top of the traps to keep the water from splashing everywhere. I am going up to the shop today and will snap some pics of them.......Ed

[Greg Maier]

I currently have straight thru tips w/ internal flappers on the 22. I am planning on purchasing a set of Gaffrig Clamp On Mufflers. That way, I can have loud when I want and with a few turns of a wrench, I can have quiet.

[RickSE]

I've been considering the same modification. Do your tips look like these?
http://www.donzi.net/forums/attachment.php?attachmentid=974

I've yet to start this motor and don't really know how loud it will be with the tips. I've heard that they're starting to check boats on my lake though, so I may just leave it as-is.

[BLACKIE]

Yo RedDog, I could not help but notice that there's a RedWing Sticker on the transom of your 22'. Good man.......As far as your exhaust question, I prefer the straight through sound. Up here on Lake St. Clair they are not too bad about the noise except in the residential canels. It really depends on your luck mostly. But knowing where you run along those rivers and small lakes you might be asking for problems. All it takes is a call to the noise police from one old lady or some over zealous non-boater and your screwed. :smile:

[roadtrip se]

Had the cans from the factory. Put the tips on with the 500.
Switch'em to thru-prop when idling next to the docks, so as to
not to upset the natives.

The tips sound better and look better. Those cans should have "folgers" printed on them somewhere, if you look hard enough!

[RedDog]

Yo RedDog, I could not help but notice that there's a RedWing Sticker on the transom ...

That's an old photo that pre-dates me. What's a Redwing - some type of bird?

[BUIZILLA]

Mufflers are cool...

J :shades:

[Morgan's Cloud]

Exact same engine (and year) with identical exhaust setup in the Magnum.
We agonised over this for quite a while when we did it and chose what we did for a few reasons.
We knew the 502 with straight through was pretty loud and we did'nt want to make any unnecessary enemies.
With the Y tubes still in place and operational any backpressure could be bled off.
And if this near dictatorship government here ever decided to act like it was interested in the environment it would probably go after noisy boats so we beat them to it.
At this point I probably would'nt change to straight through but the choice is entirely yours !

I would imagine though that the sound would get to you after a while at extended low speed running.

[MOP]

Will our current Brethren understand as we do! Been there done that! FMB

[Forrest]

On my Magnum, I decided to go with Rex Marine in-line mufflers (http://www.rexmar.com/page237.html). No detectable change in performance but a little quieter than straight-thru. It just got to the point where the noise from twins with straight-though exhaust, though sounded great, was just a little too much during long cruises. The X-18 and the 16 both are straight-thru and will remain that way. Oddly as much, the 16 with its built 302 F-motor is by far the loudest of all my boats. :biggrin.:

[CDMA]

Forrest,

I have found water to be a great muffler. I have a feeling one of the reasons the ford may be loud has to do with the volume of water pumped by the tiny Alpha water pumps. I always found the less water you pushed through the exhaust the louder it was. I noticed a big difference on my 350 when I went from Volvo, to alpha then back to large raw water pump Bravo.

Chris

[Steven Cohn]

Chris and Forrest,
I too, have found that the amount of water through the exhaust tubes makes a HUGE difference in the Db-A (AKA. rumble/roar) emitted from my twin big blocks. More H2O = lower Db-A. I have an Onan 6.5 genset that is barely audible (due to water muffling). I'd like more, but the law doesn't.
Steven

[olredalert]

-------Went with Corsa inlines on the El Pescador mainly because of spousal abuse problem. She threatened me with bodily mayhem if I didnt have some degree of decorum. I just couldnt face writing the check for 2 sets of switchable exaust set-ups either. Actually I like the sound of the 350s with the Corsas. Sort of a tamed thru-hull big boat sound. The Corsican will remain straight thru-hull. She wont even ride with me in that anyway!..........Bill S

[McGary911]

Forrest,

I have found water to be a great muffler.

Chris

I have straight pipes with external flappers, and here in NJ, on inland water, the marine police requires some sort of muffler, whether or not your boat had them as OE. I've never been stopped, but isn't the introduction of water into the exhaust stream "some sort of muffler"? I doubt this argument would flie with the MP, but it has merit. Guess I'd just have to get another 502 with a dry exhaust to fire up next to me. Then they'd appreciate my "muffler" :idea:

RD, as to your situation? If I could get away with it without getting titketed, I'd keep it loud and proud, for sure.

[RedDog]

Well the verdict is in - about 77% for straight thru and 23% for silenced. So I'm going with what I have - the silenced tips. Buizilla persuaded me with his "mufflers are cool opinion!"

Now if my eBay bid for a set of straight thrus holds, I'll have to re-evaluate my decision yet again.

Thanks for the input

[MOP]

-------Went with Corsa inlines on the El Pescador mainly because of spousal abuse problem. She threatened me with bodily mayhem if I didnt have some degree of decorum. I just couldnt face writing the check for 2 sets of switchable exaust set-ups either. Actually I like the sound of the 350s with the Corsas. Sort of a tamed thru-hull big boat sound. The Corsican will remain straight thru-hull. She wont even ride with me in that anyway!..........Bill S

We all swim in the same pond! That is when they let us!

Phil

[Greg Corey]

Here in Canada, (Ontario) they have passed laws that require any boat built after January 1, 1960 with an inboard motor to have a muffler system installed and in working order. The dB's must be below 89, except when running more than 5 miles offshore. If you are in a competition, the law does not apply. Outboards are exempt. I had to buy the switchable silent choice option for my Classic 18 just to make sure that I don't end up with a pile of noise violation fines.

[MOP]

Curious has anyone tried reverse cones inserted inside the tips? When I was racing Go Karts we used reverse cones with a driver controlled sliding pipe for tuning at speed. I pulled the cones off one afternoon the Kart was so loud our eye balls rattled, had to be at least twice as loud. Might be something worth trying, it would kick the water back up into the exhaust flow that alone would help with noise. Would it steal power maybe but with 4" openings cut back to 3" I would doubt it would do much on most of our boats. When I finally get running I will give it a try, my kid has a metal shop, will be awhile for results. Now I have two exhaust things to try.

Phil

[Greg]

Last year I ran just the straight thrus. Hard to talk and when we put up the top it seemed to hold the noise in the seating area. Put in flappers and that didn't do too much at all. So we fabricated an internal baffle system that cut the noise to a more tolerable level. That was on a 3" system. This year went with a 4" system, silent choice and the Rex Marine anglecut tailpipes with the internal muffler system that Forest showed. (the top one) I looked at the total block off in the baffle, got paranoid and had my buddy cut a 1" hole in the middle. 1 bolt and they slip right out so I figured if it was still too loud then that we could weld in ss washers till we got to a sound level that was acceptable.

[Moody Blu']

straight tips. since when will a single motor be louder then the dual big blocks out there? Ive never had a problem with marine police in NJ. Then again i have a water pump thats directly bolted to my crank and pumps out tons of water. So when i do have a water clog i hear the motor become louder and know right away no water is comin through.