Mufflers for 650 Sterlings??
 

After searching, I have been back and forth on what clamp-on mufflers to go with. The engines are N/A Sterling 650's. CMI E-Tops, with 4" tips. I have 2" of clearance betweeen the swim platform and the tips. and 2.5" of clearance between the outsides of the 2 centers exhaust tips. I have heard great things about the CMI Sound Elliminators but Gibsons and EMI look to have a good product also. The Boat is a 2003 Donzi ZX. Thanks

Re: Mufflers for 650 Sterlings??
 

I also have 645 H.P. Sterlings wtih CMI elbow tops, semi-dry exhaust. Wicked sounding, but just too loud. I was able to get 4.5" GGB Extreme clamp ons from OSO Member Lofty while they were available. Sounds great and think there may actually be a little more low end torque, no loss of top end.

Re: Mufflers for 650 Sterlings??
 

HPI is the way to go.Works great even on 1200 HP +

Re: Mufflers for 650 Sterlings??
 

Are you trying to meet any noise limit or just lower it some?

If you are not trying to meet any requirements all of those you mentioned will help cut your sound level. Meeting a noise limit is another matter!

Rick

Re: Mufflers for 650 Sterlings??
 

I have installed several sets of the GGB mufflers and have been VERY pleased with them. They really cut down on the noise level, but did require some fine tuning of the EFI at idle because they richened the motors a little. The motors were Young Performance 750 EFI's.

Re: Mufflers for 650 Sterlings??
 

No noise limits, just trying to tone them down a little.

Re: Mufflers for 650 Sterlings??
 

I wish we could still get them, it is a great product.

Re: Mufflers for 650 Sterlings??
 

sorry, but hpi's will not get you legal on a 1200hp blower motor, I tried them and they will knock off 10 dcb's got my 1150 nortech's down to 100dcb's a long way from 90 dcb limit., go with turn downs , only way to actually get legal and not chock motors

Re: Mufflers for 650 Sterlings??
 

Dude, give me a call!!

Re: Mufflers for 650 Sterlings??
 

do the turn downs sit under water when docked or just above the water line?? how much ?:p

Re: Mufflers for 650 Sterlings??
 

Which turn downs are you using and did the get your db under 90 ? Also what type of exhaust were they installed on? Wet, dry, size, hp of the motors?

I am trying to get the noise down on a pair of 1100's with cmi dry big tube headers. Need any good information anyone has.

Re: Mufflers for 650 Sterlings??
 

1180HP NORTECH blower motors running thru cmi big tubes thru wet and out 6" tailpipes on 36 nortech cat, never could get it legal, nortech now has their underwater stealth exhaust works great, like a turndown only inside the motor compartment, on a v the turndowns I had made work awesome about 2-3 " below water line, yes you can hear blower whine at idle.

Re: Mufflers for 650 Sterlings??
 

I know it's not a direct relation but should give some idea where yours may end up..

I'm running a 595hp 509 with Keith Eickerts and was 94db at idle WITH GGB mufflers....

I added a set of "downtubes" to the GGBs that sit 6" under water when at rest and now I'm at 83db at idle.....I'm not really a fan of the sound at idle but at least it's legal..


Here's a video in the water...
and a video out of the water:) ...


Doug

Re: Mufflers for 650 Sterlings??
 

If it a side by side motor setup I would put the cmi turndowns on, GLH did this on his Tiger. If it's staggered the new cmi sound elim. should work, I have them on but have not run the boat since installing them.

Re: Mufflers for 650 Sterlings??
 

More test results for you, 598 N/A, 750hp -
No mufflers: 112
GGB: 94
New CMI's: 94
Turn downs 7" under water: 86db

Rick