Exhaust silencing

[Ralph Savarese]

Well the harbor police is now after 11 years of boating in my marina saying I have to silence my Donzi I have 4 in through the transom exhaust and I want to do this with out any power reduction any sugestions . Dapars maybe? Anybody experence have with these. Will they mount between the riser and Exhaust tips?
Ralph :confused:

[David Ochs]

Hi Ralph, Did you get a citation? I have had this happen to me at one particular lake. There is always one young officer that gives me a hard time when I first start the engine. I tell him,"Let it get water through it and it will quiet down". The older officers never even pay any attention to it. It just depends on who's standing there at the time.

[Ralph Savarese]

No nothing yet but the harbor police did mention to me today that it has to be under 90 decebels or $500 first offence or arrest for second offence non repair!So i asked him if i could come buy nextweek for him to check it . I also mentioned that the boat was a 66 and is there a grandfather clause. I am looking further into the law before I make any modifications.

[Ralph Savarese]

Any body with experence with these mufflers please help!

[tamburello]

There was an article about exhaust silencer tips in Powerboat magazine a month or two ago. I have a PDF of the article and can email it to anyone that requests it.

[Rootsy]

the corsa's that come on the new classics are pretty tame... i don't have a clue how badly they hurt performance if at all... you can even listen to the radio and chit chat without issue at idle... definitely below 90 dB but not "quiet"... we have that "law" here in michigan too...

[gjohns6896]

Same stupid "law" here in Decatur! As it were, there are many-a-boats out here running with big blobks sticking out of the engine compartments and straight headers hanging off the engine yet no one seems to care. If I EVER get stopped, even by Conservation Police, I will site THEM as well. I was told that nothing will be done unless someone COMPLAINS FIRST. So, use that against them...saying no one has complained so I do not deserve a citation. :mad:

But I have also heard of the mufflers and how they guarantee a 10 dB decrease in sound but will not hurt performance. But I have only HEARD that.

Good luck, and let us all know what you do and how it performs. We all might need to do this someday if the Democrats keep running things...and those darn tree-huggers with their crapper ELECTRIC cars...give me a BREAK!
:mad:
George

[gjohns6896]

Same stupid "law" here in Decatur! As it were, there are many-a-boats out here running with big blocks sticking out of the engine compartments and straight headers hanging off the engine yet no one seems to care, and with NO water going through them either. If I EVER get stopped, even by Conservation Police, I will site THEM as well. I was told that nothing will be done unless someone COMPLAINS FIRST. So, use that against them...saying no one has complained so I do not deserve a citation. :mad:

But I have also heard of the mufflers and how they guarantee a 10 dB decrease in sound and will not hurt performance. But I have only HEARD that.

Good luck, and let us all know what you do and how it performs. We all might need to do this someday if the Democrats keep running things...and those darn tree-huggers with their crappy ELECTRIC cars...give me a BREAK!
:mad:
George

[HyperDonzi]

i saw in jegs a while back these cone shaped metal screens that are supposed to do exacly what you want, reduce noise w/o a loss in power, ill look for them and tell you pricing.

[rong]

Boy, I kringe every time I see this subject. My suggestion is not to push the subject and not do anything about it until ticketed and then fight it. Every young officer needs to be educated sometimes and a complaint really should be the incentive to ticket. Otherwise what are the specs on that 90 db. At what distance? Are they going to hang a decibel meter off the back of your boat? Haven't heard of this happening yet and hope it never comes to this. I'm sure any souped up engine will be over the limit. Finding the room and product that will work well, not counting the cost is not a plesant thought. Of course a little courtesy helps, as starting your SB at 6am or late at night raises questions as to whom your going to piss off?

[HyperDonzi]

found the insert cones, in the "exhaust" section of a jegs catalog. come in 3", 3.5", 4", (all those are 59.99ea.) and 4.5" and 5" (80 ea)

[BigGrizzly]

Thoes cones DO rob horse power!!! you will loose about 5->20%

Randy

[Rodger]

As someone in a previous reply mentioned, the level of sound is measured at a particular distance; typically 50 feet is very common. 90 decibles is fairly forgiving when measured at 50 feet, unless your running dry exhaust. If they check it, you may find you pass without much difficulty.

[Rootsy]

i totally agree with big grizzly... those cones don't kill much in the way of sound level but they do rob plenty of HP... just ask any NHRA sportsman racer... the dyno doesn't lie.. well very often :D

[RPD]

Just add twin turbochargers... they will convert some of that exhaust energy currently being dissapated as noise into HP...

[HyperDonzi]

twin turbo would quiet that down to a low power sound...
what a new thing, false advertising...

[RT]

Do you have center-rise manifolds? I have Dapers
and extra hose that you are welcome to try, if they work they will be CHEAP! I am in Babylon.
Email me at aws12@msn.com Artie.

[Ralph Savarese]

Thanks for the info guys i am hoping to go down to the harbor police and have them check it this weekend. I guess I will make a decision once I get the results . Does any one know what the regulations ao measuring distantce is or rpm ? Is it suposed to be an idle test or reving?
Ralph

[rong]

Ah, the interesting specs. Maybe what they want it to be. Be careful. Check out the law before going to the harborpolice.

[Ralph Savarese]

That is what i was hopeing someome on this sight would have any specs or know the law.

[rong]

Me too, but regs are dependent on location. I would go to the city office and ask for the recent ordinance's for boating in your area. I believe the restrictions are recent laws. In my area for example, no restriction is in place, although some street beaters get in a boat and they operate by the same rules. They learn and no trouble comes of it. Above the rules are complaints, so if someone is then the rules may not apply. I wonder how much info may be on the web?