External Mufflers - opinions please
 

Well it looks as if the Wisconsin and Iowa DNR have followed suit with Minnesota and are stopping every boat that "looks" loud and doing the 86 dba test. I have been fortunate to avoid their rath but feel my day is coming. I am looking at Corsa external muffler tips, Corsa silenced tips, Eddie Marine silenced tips, and Drew Shotguns. The silenced tips are the cheapest, but do they work and do they rob HP. The Eddies have a steel wool baffle inside the tip and the Corsa's have some sort of Bi-directional baffles inside. The Corsa muffler tips and Drews are basically the same money and will clamp onto my existing tips. In the end, I need to get more quiet but don't want to loose any performance I realized with my engine upgrade. The engine is a 509 with a HP 500 cam and Lightning headers dumping straight out the back.

voodoo,
Sorry to hear that the "boys" have found their sound level meters.. Not good..
In Mich we have to meet 90dba at an idle. So a lot of guys just use turn down pipes. They hang in the water at idle, but are open when on plane. Still pretty load when up and running. I opted to go a different route. I mounted a pair of 4" Borla stainless mufflers on the outside of the transom. I can meet the 90dba, if they check it according to the procedure. The Borla is a straight thru muff with stainless steel wool around the inner pipes. I feel that any time you put something in the flow pattern it will kill horsepower. So some type of straight thru will be better. The type with baffles will hurt the breathing. Not sure if you can meet the 86dba with anything but silent choice type setup. I used to have cans on the back and down pipes and flaps inside that I operated with silent choice air cylinders. That worked pretty good for our laws here. The shot guns will take some of the bite off it, but not much. Your 86dba standard, is that a drive by deal or what..

good luck..


Dick

What I did on my last two boats was to install downturn 60 degree elboes instead of the mufflers. The downturns end about 4or5 inches below the water line when the boat is at no wake speed. I then drilled about 20 -1/4 inch holes on the side facing the transom to relieve the thump and it will be much quieter as long as the boat isn't on plane. And the best thing is that it doesn't reduce HP

with the pipes in the water at idle, don't you have to worry about water being sucked back in or reversion? I had thought about doing this. BTW the 86 DBA is at idle, 4ft. up and 4 ft. back from the transom. I have the Salisbury flappers on the ends of my current tips and the tips also have the valves inside to stop water from washing into the tips. Can you still use the Salisbury flappers if the pipes is under the water?

If you are only looking for low noise level when idling in and out of the marina? Then I would go with the shot guns. No air pumps, solinoids(sp),switches,etc. I always like to keep it simple stupid.

Voodoo,
my friend has run the down turns on his boats with several motors.. He has CMI pipes that are dry out to the transom then the down turns go over the whole pipe. and he has no problems with reversion.. This is a big inch motor close to 600" and roller cam. If you have to meet 86dba at 4'x4' you will have to do either silent choice or down turns.. The donkey dicks as they call them are simple and cheep and dont seem to steal any power. If you want to experiment.. use some PVC to set it up temp.. if it works order some pipes from someone.. CMI did my buddies..

Good luck

Dick

There were some Drew shotguns in the OSO classifieds.That is what I am running but as to date have not been stoped so I don't know if I would make it under the gun or not! :cool:

TEAGUE TCM 450;s is all I have to say :)

They are the best IMO.
they really take the bark out both open and closed.

I feel the drews are more of a visual 'see I have mufflers' kind of thing. Never heard much change of hte 2 boats I have seen them go on.
I kow alot of people have gone with the IMCO Mega mufflers with great success. They are HUGE and you can get them either in clamp on to your existing tips or complete bolt through hull.
Not sure about the hawkeyes down there but if they are going to copy MN and WI then anything switchable is not ok. Just need to know when to and not to switch the teagues :)
When I put mine in I left the Y-pipe but took out all the silent choice acuators and vavles. Cannot see the tips from inside.
Know several others on here that are real happy with the teagues also.
I personally do not like any of the mufflers that have the external valves and hoses.

Teague Tcm 450's are the way to go. I have them for over 1 year with no problems. They sound real quiet when you want them to be. I didn't notice any power loss when open. The down side is cutting 4 1/2" holes in your transom.

I just put on a set of Shotguns on my Pantera with a 525SC. It was pretty loud. Even the water patrol at LOTO thought so:D The Shotguns helped a LOT. I'm guessing it reduced idle and cruise Db by at least 10-15. I'm very happy with them. They also have some adjustability and are an easy install.