Exhaust Mufflers
 

Can anyone suggest something that might work to get the noise level below 90db's... Are there any mufflers that work well for this?

I have Merc 525's with whipple chargers through what I believe are Stelling Exhausts...

Down at LOTO here they are cracking down on anything thats louder than 90 db and right now I'm at 96.5 db and don't feel like getting a ticked everytime I head out..

Thanks...

GGB
They brought my 1100s to 94.7

5 inch IMCO Gattlins got me 90db's with my Merc 700's

who makes the ggb's now

Thanks for the suggestions, I'll have to do something cause I wouldn't want to run the motors at any RPM with the Silent Choice which brings me to one other item.

How hard is it to replace the flappers in the Silent Choice exhaust? I worked over the pneumatic pistons, it looked like they hadn't been used in quite awhile.

I finally got them all to operate , but didn't think twice to look in the ends to see if any of them were still their... LOL....

Presently only one of the four are still around and I'm not sure how difficult or what the procedure would be to replace them. If anyone has some experience or suggestions I'd be interested in hearing them.

Thanks,

Jim

I have Livorsi E-series on my 525's and the do an awesome job!

What do you guys think of the Donkey hang downs vs the Livorsi, GGB, or Imco silent choice. Are the Donkey's quieter at the docks cause they are under water, anyone have any idea what the decible's are of the 525-700 Mercs when running on plane. Thanks Jeff

It looks like the Gibson's just slip into the end of the tailpipe, how do they attach to the existing tailpiece?

Is it through a securing bolt or other attachment of some kind?

Sorry for all of the questions, but if I don't have to do a ton of modifications and is fairly straight forward that would be the best option..

Jeff,
On ours I have tested a few and ended up with the downturns.
No muffler - 113db
GGB - 94 to 95db
CMI old version - 98db
CMI new version - 94-95db
Downturn - 88db

On your new one I would have them put in the silent exhaust. It is a much cleaner look on the transom.

Rick

I like the silent exhaust, but always seem to have a selinoid problem, hopefully they have gotten better. Actually which one's have the least amount of problems, Thanks Jeff

Jeff,
The silent exhaust that NorTech designed. Exhaust exits under #6 transom assembly. No solenoid in that one, no moving parts!

NorTech's design or downturns is most reliable - no choking off of exhaust when running and no moving parts.

That's what I wanted, but Nortech has not done one on a V yet, just the cats. I really prefer this system, nothing to go wrong, quieter, and thats what I'm after. Hopefully Terry will get it handled. Im starting a new thread, boat has started today, Build pics to follow...Terry is trying to get the boat done by end of Sept. :cool: Jeff

here is a 50 with the 'stealth' exhaust....

I guess they can't do them on the diesel V's, but it's obvious that the gas is ok, thats great news for the gas guys, thanks Jeff

They bolt on "normal" Nor Tech pipes but mine were 6.5" Stellings.
I've never seen turn downs on a Nor Tech cat.
But I'd love to see some pics if anyones done it.:D

The ones I have are more than likely CMI's and measure 6", problem I've been running into is no one seems to have anything that will work with a tube that big.

I've put in a call and sent a couple of emails to Nor-Tech but haven't been able to get anyone to respond yet, I'll probably give them a shout again in the AM...

I can't believe this is an isolated occurance (noise level) and hasn't come up before with them....

Then your decision is made....700's!

No it's not the first time.:(
I spent Thounds of dollars to try and be legal.
The GGBs will fit over your pipes mine were a half inch bigger.:D
Here's a pic of the law breakers of LOTO......well mainly Jim.:D :evilb:

This afternoon I spoke with Bob down at Nor-Tech he's going to see if there is something that they can help me with on the "Silent Choice" evidently since this was one of the first 3600's it has them and others do not.

If I can get replacement flapper/diverters for them I should be able to at least meet the idle requirement but that's not a solution.

As for the GGB's I though they folded and were no longer in business, has someone bought their assests or making the same units?

I found some GGB Insert's on eBay and figured I'd give them a try.

If you need any help give me a call.

thanks, i'll give you a shout...i'm gonna give them a call in the morning to get the shipment expedited..it's coming from canada... lol...you'd think i didn't have anything else to do during the day but what the heck i can multi-task with the best of em...good thing i sign the checks..lol...

The 5" GGB Extreme mufflers finally arrived on Friday around noon and had them dropped off at a local machine shop we do a lot of work with.

They had to be expanded to 5-13/16" to be able to slip into the end of the tailpipes so a s.s. ring was welded to both ends with mounting tabs to allow them to be bolted in three places. The first pic only has one bolt installed to align it to drill out the other two.

I was anxious to see if they would actually fit into the ends and they slipped in perfectly. It took about four hours to get them lined up and installed, wasn't in a hurry since it was raining and wanted them to be done without mistakes..lol

Here are a few pics, when I fired up the motors I couldn't believe the difference, not sure if I'm going to love the quieter sound but it will make me legal and keep my neighbors happy.

Made it all of five minutes on the water and then met WP boat on the make channel, they promptly came back and stopped me, it was the same officer wanting to know if I'd made the fix or not. I fired them up for him and told him his "Challenger" and the wifey's 883 was now louder than mine...lol...it still has some sound but nothing compared to before. The wifey likes it because you can now hear what is being said without yelling at one another...

Had to reduce size

couple of more