Rex Marine's new Silencers

[rivercrazy]

I recently purchased a set of the new rex silencers that replace the tips in a through hull exhaust configuration. Big thanks out to Shockwave for hooking me up on the install....I have a 2003 Shockwave Tremor with a 496HO. The exhaust is below the water line at idle with a lowered swim step and "S" pipe exhaust routing.
I gotta say those babies really made a huge difference quieting the boat down. I started my boat up in the marina for the first time and was shocked how quiet they were compared to stock. So quiet in fact that I thought my engine didn't start. My starter complained at me for turning the key again with the engine running. Running a vitually any speed now just requires regular voice volumes to hear people talk inside the boat. The flap rattle is also so dramatically reduced, I really can't hear them in normal boating situations.....
As for performance, I'd say overall they are pretty comparable to strait through hull exhaust on this motor. I think I might have lost a maximum of 100 RPM at the most. Boating conditions for the test was temps at about 100 degrees with almost no wind chop and pretty low humidity. Normally, I can turn either a 23P Rev-4 or 24P Bravo 1 right up to the rev limiter fully trimmed out with 2/3rds full gas tank, two passengers, fully loaded (anchors, icechests, gear, etc). I GPS'd the boat at 69.7 at 5,100 RPM with the Bravo 1 four blade (box stock). I normally use my Rev-4 and the best I've seen with that prop is about 71. The best the boat ever GPS'd is 72.8 with a labbed 24P bravo 1. OVerall - I'd say I'm very pleased and think the performance of these silencers are pretty darn close to box stock through transom exhaust.....
Thanks REX for hooking my up with a set from the first production run.....

[77charger]

wow i might have to look into them too.I would like to quiet my boat down some more as of now i think i am havasu marina safe :rollside: :)

[rivercrazy]

LOL! Those just might look like the shit on the backside of a prop!

[rivercrazy]

Heres a few pics:
http://www.***boat.com/image_center/data/520/80test.jpg
http://www.***boat.com/image_center/data/520/80test2.jpg

[phebus]

Rivercrazy, did you have your boat tested prior to the install? I'm curious what sound level you were at with the 496HO with the tips exiting below the waterline. Also it would be nice to know what you were prior to the install vs. what you are now. They look great, and I applaud you for being proactive to the new noise laws.

[rivercrazy]

I never did do any db meter testing on my ride before and after. But I can tell you its at least 2X as quiet as before.
I bet I would have passed the idle tests before the silencers but there is no way I would have passed on plane.
No I don't have to turn the stereo up as loud when were bumpin and runnin....And stealth is a good thing IMHO

[phebus]

With the downward angle the tips sit at, and their 8" length, if your exhaust exited below the waterline before, you should be well below it now, further reducing the sound levels at idle. I wish I could go with the new silencers, but my aqua step pulls down right in front of my exhaust tip, and the extended length wont allow them. I am going to look at mounting my aqua step further out, but if I do, I will have to patch the old holes, etc.

[Essex502]

While I haven't measured a box stock 496HO below water exit I know that above water those damn things are loud. Well into the 90+ db range.
I can tell you that a stock 502 MAG MPI exitting below the waterline WITHOUT mufflers but with 4" tips registers 84 db(A) on my meter at the 39" specified in the test procedure to be used starting January 1st, 2005.

[disco_charger]

I was kind of shocked how quiet your boat was! I could barely hear it before I started my boat. Seems to me that Rex has a winner with this one.

[LHC30Victory]

It appears that Rex has a winner in the Idle category with those mufflers. BUT, what about the other part of the test where the boat is up on plane? How do the mufflers work for that part?
I am seriously considering them but with twin 496ho's, I will be forking out $$$ for two pair and I want to make sure that they comply with the Kalifornia standards before spending.
Anyone have data? anyone want to subsidize a test platform? Are there ANY mufflers out there that will allow thru transom exhaust to pass BOTH tests without robbing a lot of HP? If not why not just route the exhaust through the prop?
HELP :confused: :confused:

[phebus]

I would think that some enterprising person would manufacture "launching mufflers". They could be a slip in muffler with a lever type cam lock securing them in place, and they would be installed for use around launch areas, docks, and slips. They could be restrictive so the muffling effect would be maximized, as they would be removed as soon as you left the monitored area. I realize that they would not be legal, but they sure would serve their purpose. Hell, you could even rent them!!
I can see it now, "Phebus Rent a Muffler". Headquarters: Beaumont
Slogan: "No Muff Too Tuff, Slip One In"

[JB in so cal]

I just got mine in the mail yesterday.
I'm going out to the Zoo this weekend and will be running the boat without them. If anyone has an idea where a db meter can be found (besides the marina), I'd stop by for a pre-test. They get put on next week and I'll be running at Parker the following week.
At least it would give everyone an idea of what a 496 HO puts out with above water, under the swim platform exhausts.
JB

[Havasu_Dreamin]

I was kind of shocked how quiet your boat was! I could barely hear it before I started my boat. Seems to me that Rex has a winner with this one.
Rex does have a winner with these! We have them on our 525 and were at 96 prior to the silencers installed. After installation we are at 88 db per the new CA law that goes into effect on January 1, 2005. The Silencers not only work, but they look good as well!

[Havasu_Dreamin]

At least it would give everyone an idea of what a 496 HO puts out with above water, under the swim platform exhausts.
JB
I know of one Shockwave 25 Tremor with a 496 HO with exhaust under the swimstep but above the waterline that was easily 90+ dbs.

[dicudmore]

I know of one Shockwave 25 Tremor with a 496 HO with exhaust under the swimstep but above the waterline that was easily 90+ dbs.
sounded like 92 to me :D
JB that boat is definitely too loud...
Mine was 92.8 when i got ticketed.
I've sat next to several Tremor's as they were started and they are equally loud

[PHX ATC]

Ignorant question....
I went to the lake this past Tuesday and purposely only had a very light load (me, my buddy, no cooler, and just some tools and battery/starter pack) with 1/4 tank of gas on either side.
My 2003 Nordic 25 Rage has the exhaust exiting under the water with that light load, so obviously with more gas/peeps, etc. it would still be under the waterline.
Anyone have any clue what this would read on the ole dB meter with a stock 496HO?

[phebus]

Ignorant question....
I went to the lake this past Tuesday and purposely only had a very light load (me, my buddy, no cooler, and just some tools and battery/starter pack) with 1/4 tank of gas on either side.
My 2003 Nordic 25 Rage has the exhaust exiting under the water with that light load, so obviously with more gas/peeps, etc. it would still be under the waterline.
Anyone have any clue what this would read on the ole dB meter with a stock 496HO?
Would that be with the Marina test, or a legitimate one?
The Marina tested a friends boat, with the exhaust exiting below the waterline under the swimstep, stock 496HO, and it was 84db. That said, if they were to test it again tomorrow, with the inconsistencies they use in their testing methods, I don't know what it would retest at.

[Second "PLACE"]

I recently purchased a set of the new rex silencers that replace the tips in a through hull exhaust configuration. Big thanks out to Shockwave for hooking me up on the install....I have a 2003 Shockwave Tremor with a 496HO. The exhaust is below the water line at idle with a lowered swim step and "S" pipe exhaust routing.
I gotta say those babies really made a huge difference quieting the boat down. I started my boat up in the marina for the first time and was shocked how quiet they were compared to stock. So quiet in fact that I thought my engine didn't start. My starter complained at me for turning the key again with the engine running. Running a vitually any speed now just requires regular voice volumes to hear people talk inside the boat. The flap rattle is also so dramatically reduced, I really can't hear them in normal boating situations.....
As for performance, I'd say overall they are pretty comparable to strait through hull exhaust on this motor. I think I might have lost a maximum of 100 RPM at the most. Boating conditions for the test was temps at about 100 degrees with almost no wind chop and pretty low humidity. Normally, I can turn either a 23P Rev-4 or 24P Bravo 1 right up to the rev limiter fully trimmed out with 2/3rds full gas tank, two passengers, fully loaded (anchors, icechests, gear, etc). I GPS'd the boat at 69.7 at 5,100 RPM with the Bravo 1 four blade (box stock). I normally use my Rev-4 and the best I've seen with that prop is about 71. The best the boat ever GPS'd is 72.8 with a labbed 24P bravo 1. OVerall - I'd say I'm very pleased and think the performance of these silencers are pretty darn close to box stock through transom exhaust.....
Thanks REX for hooking my up with a set from the first production run.....
Glad to hear it worked for you. What was the total cost to purchase/install?

[PHX ATC]

Would that be with the Marina test, or a legitimate one?
The real deal, not the half baked crap they pull at the marina. Although, I'm going to jump through their hoop if they're out there during the week, when I'm there.

[Tremor Therapy]

My boat has the same set up as Rivercrazy, and when we took our last weekend trip out to the zoo, the testing guy stated we "passed" the idle test. I asked him what the exact reading was, and he didn't tell me....he wasn't being a dick about it, he just moved on to the next guy.
I received my mufflers today, and I am setting up an appointment with Shockwave to install them. I will ask the ramp guys to give me a meter reading the next time out.
The price is $749 per pair, plus about 1.5 hours of labor for the install.

[PHX ATC]

Post some pictures after you get them installed.
Why did you order them up if you "passed" their hokey test? Based on the banter going on here, it seems they've been using 88 dB as their "baseline" for acceptance.

[Dave C]

sounds like the management will really have to stretch-it when they throw you out of the marina :hammer2:

[Havasu_Dreamin]

Post some pictures after you get them installed.
Why did you order them up if you "passed" their hokey test? Based on the banter going on here, it seems they've been using 88 dB as their "baseline" for acceptance.
Nope, the marina is using 86 db's at 10 ft which is not the law in AZ. If it were 88 then we would have been cool because on the db meter the Ramp Ranger used, which he admited he had received no training on how to use it BTW, we bounced around from 87-88. Said we were too loud and don't come back. Total BS!

[Rexone]

The thing is which I have posted prior in the marina thread regarding testing procedure, this procedure must be very precise pertaining to distances. My understanding is the marina is using no measured out standard, just taking 3 steps back or something and that the meter operator didn't even know the proper settings for the meter. Not to mention surrounding barriers, other noise etc etc etc.. I would consider all results out of that scenario to be pretty bogus and meaningless.

[PHX ATC]

Agreed.
I stand corrected (or sit) about the 88 vs 86 dB. ;)

[Essex502]

Ignorant question....
I went to the lake this past Tuesday and purposely only had a very light load (me, my buddy, no cooler, and just some tools and battery/starter pack) with 1/4 tank of gas on either side.
My 2003 Nordic 25 Rage has the exhaust exiting under the water with that light load, so obviously with more gas/peeps, etc. it would still be under the waterline.
Anyone have any clue what this would read on the ole dB meter with a stock 496HO?
Probably not much louder than my 502 underwater @ 84 db(A) at idle from 39" away (CA test)

[Tremor Therapy]

Post some pictures after you get them installed.
Why did you order them up if you "passed" their hokey test? Based on the banter going on here, it seems they've been using 88 dB as their "baseline" for acceptance.
I did so for a couple of reasons....
1) My boat will have visible "mufflers" and hopefully this will get me to the front of the line, and not hassled at any ramp anywhere.
2) Under WOT, my exhaust is not under water, and remember....this is not just an idle test, it is under WOT conditions as well.
3) When LE is cruising looking for a reason to pull you over, my boat will have the mufflers, they will see them (you can't miss them), and hopefully I will be one of the boats they pass right on by.
4) I heard that the fine for this is something like $300 per infraction, and it is not a fix-it ticket. You can be out for a weekend, and get ticketted on multiple occassions!
5) I just wanted to give that little black rain cloud another reason to pass me by! :p

[atomickitn]

hey lhc30victory in responce to your question i am the rigger at dana and have been testing those tips for overa year am realy pleased with the results but they are a pain in the ass ,they only take 1to2 hp all the wile meeting the required laws,in the testing we only lost .5 mphs

[boatnam2]

so when is or does rex marine have any plans to make slip on's.