Exhaust/Mufflers
 

What is the best exhaust system to maintain dB compliance of under 90 without a power or speed loss for a ProCharged 7 psi and Injected motor about 825 HP?

I'm currently working on building some turn downs with mufflers built in. I run on the Chain as well and as you know noise is the hot topic right now. I will try to keep you posted with details. I plan to market my design soon for local guys. I am also building some 850 hp motors so what I design should work for you as well. I am hopefully going to be 50% less cost than what is out right now.

Smitty

You might try GGB. They work well on my 750 HP normally aspirated.

Exhaust/Mufflers
 

I recently tried the CMI Sound Elimination mufflers. Quiet @ idle and open up as exhaust pressure increases. Not quite as loud at WOT. No loss of performance. 540 600 hp motors in 35' Cig.

I run GGB Extremes on my 725 HP, NA 540. They work great, however, as far as I know they are no longer in business.:(

How much for CMI mufflers?

I am running 4" Bola SS mufflers and Drew shotguns. 88dba at idle, takes the bite out of the wot.. breaths freely. Not the prettiest, but it is functional. The noise cops havent pulled me over yet...

I'm running GGB's with turndowns...

600 hp 509 with Keith Eickerts.

Only 83 db's at idle, NO power loss..:D

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I see GGB's website is up again... don't know if their still in the "marine" side of things though...
http://ggb.ca/


Doug

Getting the pontoon ready Bob?

I modified a set of stainless 5" HPI's by cutting 90 degree stainless tubing and welding to HPI out lets.

They are very quiet even at speed all you here is blower wine.

They did however bring our EGTs on our 1300hp engines up to an unacceptable temperature level at high rpm.

I believe the HPI's would work well up to 1000hp or or so as they are similar to my GGBs and they worked real well on my Gun with 850HP mills with no noticeable power loss and acceptable EGT's..

Good Luck, I'm still searching for something that will work on my set up, I would be happy with 100dbs at idle.