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September 14, 2012

Hello People,

The code has a set distance it must be measuered from, heres what the code states:


654.06. No person shall sell or offer for sale at retail any internal combustion engine for use on any motorized recreational vessel which, when operated, exceeds the following noise levels:
(a) For engines manufactured on or after January 1, 1974, and before January 1, 1976, a noise level of 86 dbA measured at a distance of 50 feet from the motorized recreational vessel.
(b) For engines manufactured on or after January 1, 1976, and before January 1, 1978, a noise level of 84 dbA measured at a distance of 50 feet from the motorized recreational vessel.
(c) For engines manufactured on or after January 1, 1978, a noise level of 82 dbA measured at a distance of 50 feet from the motorized recreational vessel.

The meter reading should be taken 50' from the boat.
Are these California's standards?
 

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Almost , you have been given a lot of good feedback and info here , the sad reality is these laws don't allow for much compared to what we could get by with for years and that to get any header equipt boat especially one with any compression eve close is not simple and not inespensive as you likley realize , several years back anticipating these laws we tested nearly everything available and could get close on a the two boats we were using with both a set of internal mufflers in combination with a set of Drews We were able to get one boat to 84 DB and one to 86, bear in mind that a late model truck with a Flowmaster is close Decible meters are fairly inexpensive and can be a handy tool in trying to beat this I'll loan you mine if you decide to go forward Good Luck ! Tom
Heres a couple examples ...




 

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I just called Rex the are out of the shotgun tips you guys bought all of them she said HA/HA!! Also I called drew but got voice mail his are $500 and $800 ouch!!!!!! I think I am going to cut the bells off the headers. when I was at my buddys shop that builds drag cars thats the first thing he said that the bell end is making alot of the problem. who else sells the shotgun tips?I could fab up some down spouts but it will look like semi stacks hopefully I can get this fixed without doing that but good idea guys!!!
Can't help you with the Shotgun tips. But FYI: I'm running a pair of the Shotgun III tips, along with a pair of 4" Vortex inserts in a through-transom 4" set-up. The Shotgun's help the noise, and add no backpressure. With OT headers I think you'll still be too loud with just the Shotgun's installed. I added the Vortex inserts, and the noise level went down some more, with no increase in backpressure (I measure it at the logs). I've tried lots of things to try to keep the noise down while limiting backpressure/power loss, and this has worked the best thus far. Unfortunately, I don't have sound pressure level measurements to tell you how much the reduction is. Only my uncalibrated ear....

The GGB inserts look intriguing. I might have to try a set of those in place of the Vortex inserts.....

Good luck.
 

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Can't help you with the Shotgun tips. But FYI: I'm running a pair of the Shotgun III tips, along with a pair of 4" Vortex inserts in a through-transom 4" set-up. The Shotgun's help the noise, and add no backpressure. With OT headers I think you'll still be too loud with just the Shotgun's installed. I added the Vortex inserts, and the noise level went down some more, with no increase in backpressure (I measure it at the logs). I've tried lots of things to try to keep the noise down while limiting backpressure/power loss, and this has worked the best thus far. Unfortunately, I don't have sound pressure level measurements to tell you how much the reduction is. Only my uncalibrated ear....

The GGB inserts look intriguing. I might have to try a set of those in place of the Vortex inserts.....

Good luck.
You measure back pressure? Cool...Never checked a boat motor. Years ago we did some cars, if i remember the rule of thumb was like 2 psi @ wot was where power started taking a hit..Messed with a bunch of bike stuff. Might have just been me not hitting the jetting spot on but a lot of stuff pulled better r's with kind of a crappy baffle and 3/4 psi than open exhaust.
What do you for fittings? I used to use drilled out zert fittings..drill a pilot hole and screw them in and slide a hose over
and stick a none drilled fitting in when done. Ok for a car..not to slick for a boat....although it is the hot tip for keepin grease in them pesky muff bearings:rolleyes:
 

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You measure back pressure? Cool...Never checked a boat motor. Years ago we did some cars, if i remember the rule of thumb was like 2 psi @ wot was where power started taking a hit..Messed with a bunch of bike stuff. Might have just been me not hitting the jetting spot on but a lot of stuff pulled better r's with kind of a crappy baffle and 3/4 psi than open exhaust.
What do you for fittings? I used to use drilled out zert fittings..drill a pilot hole and screw them in and slide a hose over
and stick a none drilled fitting in when done. Ok for a car..not to slick for a boat....although it is the hot tip for keepin grease in them pesky muff bearings:rolleyes:
I drilled & tapped my logs for 1/16" male NPT fittings, per the attached file. I use 1/8" nylon tubing to make the connection. Since the flow is dead-headed, it doesn't overheat. And I can move the nylon tube to other places around the boat (e.g. suction pressure, cooling water pressure).

I should qualify "no backpressure": I really mean minimal backpressure. I measure approx. 1 psig on my 496 Chevy at WOT (4600 RPM with a 9.25" impeller). I measured about 6 psig through some 4" fiberglass ski boat mufflers that I had installed for a couple of years. But they cost me 150-200 RPM.
 

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I drilled & tapped my logs for 1/16" male NPT fittings, per the attached file. I use 1/8" nylon tubing to make the connection. Since the flow is dead-headed, it doesn't overheat. And I can move the nylon tube to other places around the boat (e.g. suction pressure, cooling water pressure).

I should qualify "no backpressure": I really mean minimal backpressure. I measure approx. 1 psig on my 496 Chevy at WOT (4600 RPM with a 9.25" impeller). I measured about 6 psig through some 4" fiberglass ski boat mufflers that I had installed for a couple of years. But they cost me 150-200 RPM.
Excellent:))THumbsUp 1 psig is about as good as it gets....6 is a bunch, i'm surprised they only cost you 150-200 RPM. I tried a set of baffles on my deal that barely cut the noise but they did take some of the 'sharpness' out of it and they cost me 600 rpm.

Guess i ought to start checking pressure. I don't really care for a lot of noise, it's ok for drag racing/short runs but last time out i ran 18 [email protected] 6k+ and it got old.
Thinking that i might put turbo mufflers on my next build. The kind that turn exhaust pressure into intake pressure:shock:
 

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Discussion Starter #47
well I am happy to say I just got my boat out after alot of changes an money to try and quiet it up some. I did the basset stage 1 mufflers and shotgun tips also new headers with out the bell end and we went by 3 sheriff boats and nothing but a wave back!!! as we went by. didnt see the DNR guy but it cant be to bad if the sheriff didnt say boo. if I ever get db tested I will report back with the numbers
 

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Good for you. Glad to hear you get to keep your boat. So how much did it end up costing you performance-wise? RPM/MPH?

I'm originally from the Upper Penninsula of Michigan and if I tried to run my boat up there, the worry probably wouldn't be the cops or DNR. It would be from the civilians........

They might think it was cool for a pass or two, but that would be it.
 

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Discussion Starter #49 (Edited)
yea Im glad it went well goin buy the fuzz. IT is quieter for sure. I was a little worryed when I pulled in to the landing and there was 3 trucks with lights on the top.I guess I dont know what would have been worse the dealin with the fuzz or the wife after all the cash I spent LOL!! I cant say for sure on HP loss yet also i had full tanks my kids and wife/ cooler /big bag of tools just in case . I would have to pull motor and re dyno with headers and look at the numbers to realy know but I stomped on it up river and it feels strong still and with all the extra weight in it. im happy with it so far. I spent some cash for sure I would have to add it up but $2000/ $3000 but I did buy some bling since I had to changing evac from headers to puke tank plus have you gottin any SS bolts lately man the hardware store loves me. money well spent to stay boating!!!!!! just dont tell my wife how much I spent LOL!!!
 

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I just wanted to add that you can get an DB meter app for your smart phone. We compaired it to my buddy's nice DB meter and it worked the same. Sorry I forgot the name of the app but it's not too hard to find. My BBC with Summit Racing open header baffles idles at 90 DB. I haven't ever had a problem with cops so far. I will say a buddy of mine has the supertrapps and those by far work the best. Best thing to do is avoid the cops and if you think your getting stopped maybe try pulling a couple sparkplug wires?? I might try that and see if is makes much of a differance in DB?
 

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Glad to hear that you successfully made for first official sound trip a good one! I love the look of your exhaust, black with chrome tip section!
 

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Discussion Starter #52
thanks !! yea I like them also.they started to discolor from the heat a little I think I may have to buff them up now and then. they do help with the sharpness of the sound at idle and just cruising speed but when you stomp on it not so much.
 

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Discussion Starter #53
I just wanted to add that you can get an DB meter app for your smart phone. We compaired it to my buddy's nice DB meter and it worked the same. Sorry I forgot the name of the app but it's not too hard to find. My BBC with Summit Racing open header baffles idles at 90 DB. I haven't ever had a problem with cops so far. I will say a buddy of mine has the supertrapps and those by far work the best. Best thing to do is avoid the cops and if you think your getting stopped maybe try pulling a couple sparkplug wires?? I might try that and see if is makes much of a differance in DB?
let me know what you get for results
 
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