Exhaust silencers

[crf311]

I put a set of the rex inserts on my OT headers, but would still like to get it a little lower. My question is ,anyone running both inserts and clamp on silencers on OT headers? If so how much sound did it knock off? I'm not worrried about losing a couple of RPM's. Thnaks

[sleekcrafter]

I have 4 mufflers in my Basset OT's, two in each side. I knocks the bark off really well, but I will not pass the idle test, Imm looking into thw Silent "E" series mufflers by Northstar Marine, sold by Livorsi. They are designed for wet exhaust, but I'm considering trying them with injected headers, being dry at idle to 1500 rpm. Here is a link for the muffler showing a cut-a-way view. this seems to be the best performing muffler for exhaust above the water line, bar none.
http://www.livorsi.com/catalog_pdf/***boat.pdf
http://www.livorsi.com/images/catalog/e_series/ESERIESTRANSOM.jpg
http://www.livorsi.com/images/catalog/e_series/ESERIESCLAMPON.jpg

[crf311]

Thanks, I was looking at those last night. Also looked at a set on ggb.ca. GGb showed a jet with OT headers with both a insert and clamp on but didn't say much about it. I guess I'm getting old. When I was building my jet I wanted it loud, but now that I have used it a couple of times I would like to be able to speak to others in the boat without screaming.

[FASTRAT]

Thanks, I was looking at those last night. Also looked at a set on ggb.ca. GGb showed a jet with OT headers with both a insert and clamp on but didn't say much about it. I guess I'm getting old. When I was building my jet I wanted it loud, but now that I have used it a couple of times I would like to be able to speak to others in the boat without screaming.
when i lived in Cal...i ran Supper Trapps...u can adjust the noise level by adding or subtracting the baffles without any power loss...i had n/p hearing people in the boat...just my .02 cents
fastrat

[Rexone]

Keep in mind the Northstar muffler is pretty heavy for OT exhaust and also it's very quite at idle but as soon as it opens gets pretty noisy. Hate to see you spend a bunch of money and have them crack your headers due to weight. I'd think header braces with those would be a must.

[Heatseeker]

I know someone who's running the GGB mufflers on a hydro. Without baffles, he's at 93 db @ idle. Engine is mild, 9.5:1 w/ a lopey cam. He only lost about 100 rpm on top.
From what I've been told, Supertrapp is no longer making the adapters for 4" collectors. And they rob alot of power when you get the dbs down to legal ranges. The above boat lost 300 rpm on top when at 95db @ idle w/o baffles.

[sleekcrafter]

I do have header braces presently, your right, about the weight issue hanging on the headers. I think some of the collector could be trimmed back to reduce the stress as well.
http://www.hotboatpics.com/pics/data/500/7363100_0342.JPG

[Rexone]

From what I've been told, Supertrapp is no longer making the adapters for 4" collectors. And they rob alot of power when you get the dbs down to legal ranges. The above boat lost 300 rpm on top when at 95db @ idle w/o baffles.
Correct... we used to sell quite a few of those.

[Rexone]

I do have header braces presently, your right, about the weight issue hanging on the headers. I think some of the collector could be trimmed back to reduce the stress as well.
http://www.hotboatpics.com/pics/data/500/7363100_0342.JPG
It appears you have flared collectors from the pic. I believe the Northstars are designed to clamp on a straight 4" tube. I would check with Tom Beson (at Northstar, the manufacturer) too to see how applicable they would be without much water passing through. Easier to ask before buying than trying to return used silencers that didn't work out for some reason.

[sleekcrafter]

It appears you have flared collectors from the pic. I believe the Northstars are designed to clamp on a straight 4" tube. I would check with Tom Beson (the manufacturer) too to see how applicable they would be without much water passing through. Easier to ask before buying than trying to return used silencers that didn't work out for some reason.
Rexone, thats in the works now, A friend of mine is in contact with Mike at Livorsi on this issue. As far as the differences in pipe diameter that will be addressed when the time comes. I have full access to a machine / fabrication
shop to make this work. I if it comes to having Basset HP mufflers in the collector as well as the Silent "E" mufflers so be it, as of now I'm on borrowed time for the noise laws. Here in Illinois, they have one of the stiffest penalties for excceeding 90 db, $1500 and up to six months in the pokey. Iowa and Wisconsin are more strict on the noise 86db and a choice of ticket prices between IA. and WI ranging from $100 to $300. they are targeting "stock" Jet boats with log manifolds, saying the are too loud.
At a meet on the Mississippi, we sound checked al our boats, not one would have passed, even at idle with the exhaust under water. Some run mufflers and some not, the DNR uses a PVC pipe contraption, basically an "S" pipe, and sticks it over the exhaust pipe when it is submerged, and administers the test with the meter in the end. This noise thing is way out of hand, my boat just looks loud, there for I feel I will be a victim of a noise ticket shortly when they prowl about. I'm not as loud as some stock jetboats with log manifolds, on plane,but I cannot pass the idle test.
That being said, I realy have no I have no other options, without extreeme corking of the motor, seems they (the DNR) olny care about the idle tests. And the fact that my Southind Tunnel Dragster has no provisions for a wet exhaust / thru transom system.

[crf311]

Mike,will your power silencer clamp on to a 4" OT header? My OT headers are the flare style but I can cut off the flare. When I installed my inserts, which purchased from rex, I slide them up in the collector and drilled a new hole to secure them in place.

[Rexone]

Mike,will your power silencer clamp on to a 4" OT header? My OT headers are the flare style but I can cut off the flare. When I installed my inserts, which purchased from rex, I slide them up in the collector and drilled a new hole to secure them in place.
No they are designed to transom mount (tip replacement). They would not be quiet enough anyway without running full water through (water inj would not get the job done).

[Rexone]

Rexone, thats in the works now, A friend of mine is in contact with Mike at Livorsi on this issue. As far as the differences in pipe diameter that will be addressed when the time comes. I have full access to a machine / fabrication
shop to make this work. I if it comes to having Basset HP mufflers in the collector as well as the Silent "E" mufflers so be it, as of now I'm on borrowed time for the noise laws. Here in Illinois, they have one of the stiffest penalties for excceeding 90 db, $1500 and up to six months in the pokey. Iowa and Wisconsin are more strict on the noise 86db and a choice of ticket prices between IA. and WI ranging from $100 to $300. they are targeting "stock" Jet boats with log manifolds, saying the are too loud.
At a meet on the Mississippi, we sound checked al our boats, not one would have passed, even at idle with the exhaust under water. Some run mufflers and some not, the DNR uses a PVC pipe contraption, basically an "S" pipe, and sticks it over the exhaust pipe when it is submerged, and administers the test with the meter in the end. This noise thing is way out of hand, my boat just looks loud, there for I feel I will be a victim of a noise ticket shortly when they prowl about. I'm not as loud as some stock jetboats with log manifolds, on plane,but I cannot pass the idle test.
That being said, I realy have no I have no other options, without extreeme corking of the motor, seems they (the DNR) olny care about the idle tests. And the fact that my Southind Tunnel Dragster has no provisions for a wet exhaust / thru transom system.
Damn those are some tough noise laws, worst than Ca. This noise ticket crap is sure getting old. :mad: friggin retard treehuggers

[sleekcrafter]

This was another set that faired well on the db tests,http://www.imcomarine.com/pages/images/gat-72.jpg
c
They are the IMCO mega mufflers
http://www.imcomarine.com/pages/images/mega-704co.jpg
These are Gatlin mufflers that may do well with out water
http://www.imcomarine.com/pages/images/gat-72.jpg

[Heatseeker]

Something I forgot to add in my earlier post above: Make sure you secure those mufflers GOOD! The hydro I talked about popped one of those mufflers off at the delta. $180 replacement cost!!!
Nail 'em down tight!