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  1. #11
    Join Date
    Dec 2015
    Location
    Lake Nottely, Blairsville, GA
    Posts
    1,247

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    Love this thread. Great job on the specs.
    However, my thought process works a little different than yours. The way I combatted the noise of the exhaust on my Sunsport 242 was to increase the decibel of the stereo system. Seriously.

    At one point, I did think about FAE install but it has mixed reviews. Yes they work...when they stay attached to the boat. Referring mainly to aftermarket on older inboards.

    Mufflers are cheap as I know several friends and family included that have had issues with them. My Sunsport 242, which has the ULTRA barrel style muffler, has now decided to implode. The baffles have come loose inside and it sounds like rocks in a washer machine. So, I'm going muffler delete using FAE straight pipes. I don't think it will make it any louder and I honestly love the sound of my inboards.

    I'm at the lake...in an inboard...what's not to love about that sound?

    1983 Supra Rider aka Mischief IV
    1983 Supra Beast
    1985 Supra Rider
    1986 Supra Sunsport Skier
    1987 Supra Marauder
    1991 Supra Comp ts6m
    2012 Supra Sunsport 242

  2. #12
    Join Date
    Dec 2011
    Location
    Vonore, TN
    Posts
    123

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    My muffler is mounted in the engine dog house. 91 comp. silent muffler. Think it may be the only existing one that hasn’t had the baffles burnt out of it. It is quieter than most but at 22Mph has a hum that could drive you crazy too, so may not be for you. Just a different sound. Super quiet at slalom speed though and at idle really don’t hear it running. Will try and find picks.

  3. #13
    Join Date
    Aug 2010
    Location
    NJ
    Posts
    1,393

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    Good point about FAE staying attached. I was also concerned about drag and force on the mounting brackets as I've read a few people have had issues with parts coming loose. I also prefer to hear that my engine is running, but I'll take silent or bubbly if I can't get there with mufflers. That's disappointing about the Ultra Marine mufflers failing (particularly on a newer EFI boat less prone to backfire), I got the impression they were a little better than Centek. It may come down to inherent weakness in any fiberglass muffler and luck of the draw. I've not found a stainless, long, small diameter ski boat style muffler. I think having the multiple partially water filled chambers is necessary to get a significant volume reduction. I considered straight turndowns but think they may increase noise in the boat and the rubber flappers probably have a similar but less pronounced redirection. The silent rider style muffler on the back of the engine would be an option if I could find one with 3.5" in and 3" out, and certainly easier than pulling up the floor, but I'm only found 3" in/out. I won't have room to fit the reducers on there for a 3" in.

    I'm a lifelong gearhead and love the sound of a healthy V8, but as I get older I'm realizing hearing damage adds up over the years. My goal with this project is primarily to preserve what's left of my hearing. I have a few vehicles and have taken steps to quiet them all down and now wear earplugs every time I ride a motorcycle even with quiet exhaust, for wind noise. Hearing loss sucks and can sneak up on you over time.

  4. #14
    Join Date
    Feb 2014
    Posts
    105

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    Do these FAE's actually fall off? Run the Comp at 34/35mph everyday, while skiing, and it hasn't budged in 2.5 years. Have had it over 40mph occasionally.

  5. #15
    Join Date
    Aug 2010
    Location
    NJ
    Posts
    1,393

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    The Gibson muffler tips arrived today. I don't expect a significant volume reduction from the straight through with baffle design, but it's similar to a glasspack you'd use on a car but using water instead of fiberglass to muffle the sound. They are very short at about 6-5/8" overall with only 3-1/2" beyond where they slide into existing 4" tips. They slide about 3" over the existing tips, and the inner baffle goes up into the tips 3-5/8". This means they won't fit the Hardin Marine tips with baffles installed as there is only 2-7/16" from the center baffle to the end of the tip. The slot where the two bolts clamp onto the tips is also too narrow to slip past the bolt holding the baffle into the tips.

    I will modify these to fit by widening the slot to about 1/2" to clear the bolt holding the baffles, and cut down the inside inner baffle to 2-1/4" or less, maybe 2". This will result in 3/16" to 7/16" of open 2.5" exhaust (ID of inner baffle) at the end of the Gibson tip, plus the area of the louvered baffles. Much of the exhaust gas will have to make a 180* turn and the rest will go through the louvers mixed with water. I suspect this will result in fairly significant volume reduction and a much more effective muffler than either Hardin Marine Baffle or Gibson tip alone.

    This may be the hot ticket to get it where I'm comfortable, though it may be too restrictive on the top end. If it is too restrictive at high RPM I will remove the tips and trim more from the inner baffle until performance is acceptable. Given the low HP per cubic inch of the PCM 454 I don't expect any significant performance change.
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    Last edited by cadunkle; 07-23-2020 at 09:12 PM.

  6. #16
    Join Date
    Jun 2010
    Location
    Oregon
    Posts
    328

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    I've had my comp for over 35 years and tried many different ways over the years to quiet the rumble. The exhaust pipes are 3". So is a 2" glass pack. I got 2 -32" glass packs removed the guts. Took the baffle back to the muffler shop and had them flare the ends up to about 2 5/8 ". Raped the fiber glass back on the baffle and slid them into the 3" exhaust pipes. I know this is not Maurine and one would think that it would rust away but, 3 years so fare. The Ford sounds grate and I think it likes the little bit of extra back presser.

  7. #17
    Join Date
    Aug 2010
    Location
    NJ
    Posts
    1,393

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    Very interesting about running glasspacks. I'm surprised they muffle well with the fiberglass saturated. Wet packing permanently reduces muffling performance on motorcycle mufflers, a problem when hosing down dirt bikes or on two strokes when the packing gets too saturated with oil. The constant flow of water probably makes up for it. I suspect 2" would be a little restrictive for a 454 though. Thanks for the details of your solution and experience.

    I modified the Gibson mufflers today, shortening the inner baffle by about 1.25" (2" cutoff wheel on a die grinder) and widening the relief slot where they clamp on (3" cutoff wheel). I made a mistake measuring how far I needed to widen the relief slot for the bolt on the Hardin inserts, and did not wider the slot far enough. They are almost all the way on but seem pretty solidly on there and are clamped tight on both the bolt for the baffle and the pipe itself. I may lengthen the wider portion of the slot a bit to get them on farther. My other oversight was not realizing I needed to make a relief cut on the inner baffle to clean the bolt and nut inside the Hardin tips. I made this relief by cutting the baffle with a sawzall along each side of the slot for the clamp bolts and baffler bolt. I then folded the remaining inner edges of the baffle up (needle nose vice grips) to clear the bolt and nut for the Hardin insert.

    The result idling in the driveway, measured same as before, 20' behind the boat and a few feet to the right is about 75 dB but spiked up to 76 dB occasionally and then in the driver seat is 72 dB. 5' behind the boat and a couple feet to right measures 82 dB.
    No baffles: 87 / 77
    Baffles: 81 / 72
    Baffles+flappers: 81 / 72
    Baffles+Gibson+flappers: 76 / 72

    I'm very impressed with the muffling performance combining these two mufflers. It is very quiet at idle. I suspected this would be very quiet acting as a chambered muffler. I'm curious how it will perform on the water, I suspect noise reduction will increase with more water flow. If they perform as I suspect they will and they don't fall off, I think this will be the hot ticket for my needs. I'll probably be out tomorrow to test.
    Attached Images Attached Images

  8. #18
    Join Date
    Aug 2010
    Location
    NJ
    Posts
    1,393

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    Tomorrow came 11 months later. I haven't used the boat at all until a couple weeks ago when I brought it to the lake house. I forgot my decibel meter, but anecdotally I'm thrilled with the performance of this muffler combination. It still has a noticeable rumble at idle and nice tone at wakeboard speeds, but is much quieter. Still louder than an I/O with exhaust under water but this setup is working for me and worth every bit of effort making it fit. Definitely easier than installing traditional fiberglass mufflers under the floor, which seem to have questionable longevity and can put a lot of water in the boat when they fail.

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