100 Dba
 

Just took a reading and i'm at 100 Dba with my open exhaust. Currently I am looking at the following (3) systems:

Eddie Marine switchable - Replaces existing tips

Rex Marine switchable - Replaces existing tips

Drew Marine automatic - Bolt on

They all claim anywhere from 10 - 14 Dba reduction at idle, which gets me legal. Out of the three, which is the recommended?

I don't have any of those systems that you mentioned. I do have experience with the Teague system though. I don't know if you have considered them or not, but the pricing is quite attractive.

I have Shotguns and like them, but I doubt they will get you quiet enough to be legal if you're at 100db. Thats pretty LOUD for a single. Did you take an ambient noise reading prior to the 100db reading???

How far away from the boat are you taking your readings from?

My shotguns only dropped me from 96 to 92. Which is really a lot. I would wonder about any 10 db claims in the 100 territory. I assume your running dry pipes.

Pantera 24,

This will sound cheesy, but it worked really well for a friend of mine.

He went to Home Depot and bought some 4 inch PVC pipes and fittings for a total of $30 for 2 engines. Not the heavy weight schedule 40, but the lighter weight pipe. He had a 45 degree bend and 6 inches of pipe on one end that slid over the tail pipe. He slit the pipe a couple of times and put a hose clamp on to hold it to the tail pipe. He then put another couple of inches of pipe on the back of the fitting and attached his exhaust flapper to that pipe. The end of the pipe has to be below the water when the boat is at idle. He said all he heard was bubbles and the water swirling behind the boat. He can also remove them in just a few minutes (4 hose clamps). No performance difference noticed.

I am going to build a couple. If they work well I will use them as templates and send them to CMI or some other exhause company to make out of metal.

Steve

I took the reading after zeroing the gauge for ambient noise.

I took the reading 3' up and 3 back form the exhaust.

I'm running wet pipes.

The piping you described sounds like it would work, I would assume the DNR would know what I was doing.

I'm trying some Drew Marine Shotguns Friday, I'll post the results.

Kirk

Take a look at some transom shots of boat picks. I have seen many people do this. I know of several people in MI that have done this, Mr Gadgets friend Steve H. comes to mind. Cheap and effective. I have Teague Switchables, I went from 95 to 89 ish. I would recomend them in a heart beat. BUT when they outlaw switchables I will go the pipe route.

You won't make it with shotguns. They'll only drop it a couple of dbs.

Kirk,

I'm using Teague switchables. They recommend running up to 3000 rpm closed. Was that you at West Marine last Sunday?

Mark

Would anyone be interested in sound level meters.

The Brand spanking new fountain 35" next too me in the marina, has stainless 90* elbows(factory) that take the exhaust a cpl inches below te waterline while not on plane..... I was thinking of doing somthing similar with 45's on mine.

i have the eddie marine switchable and love them...
can't believe how quiet they are once the water starts flowing good..

Don

Fabrication
 

I have the equipment and materials to fabricate the same thing that you guys are making out PVC, except mine would be stainless tube with orbitally welded joints.

If there were serious interest, I'd be willing to fabricate a couple sets as templates or demo models and I could post pictures.

Each boat would be different due to the distance from the tips to the water. I would expect that a clamp on style would only be for a prototype. The real tips would need to be welded or bolted to your existing tips or fabricated to completely replace your existing tips. Clearing steering rams and the drive in the up position may pose a problem.

If there is enough interest, I'd consider making them.

Kirk call George up he's got a set of like new used electric selectable tips for sale,I believe they are Gaffrig by Lovorsi.

just my .02 I've got the shotguns, and at idle (650rpm) they do the job very quiet, but.....go to 750 rpm they get loud quick!

Re: Fabrication
 

Gil marketed a cast version at one time. When I did my exhaust last year I tried to find some, but they had dropped them due to not enough interest. Maybe the current rash of noise enforcement would help rekindle the interest?

-Greg

The shotguns work well around dock, and in no wake zones. They are adjustable as to how fast they'll open up. But, I don't know if you will get a 10db drop. That's a huge change in the volume of noise.

I am curious as to actual before/after with the noise meter with the shotguns.

Hey Steve -

I spoke to George. I picked up a set of Shotguns already prior to speaking with him. Hope all is well with you.

I'm planning on installing the shotguns tomorrow. I take actual befor and after readings and post them here. Even if I'm not legal, I'd like to be a little quieter around the docks and channels. Also, if its not rattling their teeth, maybe the DNR and cops will leave me alone.

I'm just a little 24' boat trying to have some fun!!

I bought a pair of cyclone clamp-ons from cp perf. ended up taking them off because I thought the damn thing sounded like regular thru-hull when I was running gil dry pipes. I think they're alot quieter than shotguns. I'm selling them on ebay right now

I couldn't find them on Ebay. PM with a price. I tried the Shotguns.....4 Dba lower only.

My new readings were 96 Dba without and 92 Dba with....

Thats exactly what they did for me, even with very strong springs.

pantera e-mail me and we'll chat or item#2426776261 [email protected]

You have to remember that for every 3db of change that is either a doubling of noise or halving it, depending on which way you go. To knock 4db out is a big jump. Still not enough to make it legal.
I am running Borla 4" x 16" mufflers with the old style Drew's, with totally dry exhaust. Works quite well. I intend to buy new ones and that will decrease the noise even more, because the holes are in the bottom of the Drew, which is dragging in the water at idle. Now for those late nite excursions when stealth is very important.. a switchable is necessary.
And when measured with my Radio Shack meter, by Michigan law, 1 meter back and 1.5 meters up (3'x 4.5') I see below 90dba. That is at 700 rpm. When in gear I can get it to idle around 550-600 rpm and the officers leave me alone.

Hope this helps.
Dick

Pantera cp performance has the cyclone silencers also for higher HP as well up to 650 for $479

Thanks Homan,

I'll look into them.

Ive heard the ST 450 teagues there good!!

I got around to measuring my boat this past weekend...

110db open, 102db with the Teagues closed.

We have the solution that you are looking for. We are running a 20% discount through the end of September. Give us a call we will get you to the right db level without losing any HP. 1-866-843-1900.

Did a sound check on my 502's last week....the F302 came from the factory with a swim platform and 330s so the 3" stock pipes were about half under water on the transom. I opened it up to 4" dia when I put the new 502's in....and put the drew shotguns on it at that time. I measured at 88 db at idle 3 ft behind with both motors idling at 650 rpm. Maybe could get a tad lower if you and the passengers went to the rear of the boat when they take the test....but the slots in my shotguns are already underwater anyhow about an inch....