silent choice?
#13
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Loto.... it matters not which you get, switchable mufflers or Corsa Quick & Quiet (y pipe thru hub).... NONE can be used above 3000 rpm as they are too restrictive. Still, I know I can run 45 mph and still be under 3000 rpm.. so you can still cruise and be quiet... just not at WOT..
#16
I have Teague's and they work great but they are not as quiet as thru hub. I have run them up to 3500rpm but I think that is pushing it 3000rpm is probably best. 525 blown motor on CMI exhaust.
#17
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Join Date: Feb 2001
Location: Stuttgart, Germany
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On a 454 Mag you will hardly notice a difference in performance between open and closed mode.....in my boat with the same engine about 50 rpms. I run the Corsa electric system and am extremely happy with it. Dont go the Merc route, too much weight with all the pumps and lines to install and a lot more complicated too.....
#19
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Join Date: Oct 2000
Location: Kentucky - where the women are so fast we have to put a governor on 'em!!
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Does anyone know what actually does happen when you go beyond 3000 rpm with the exhaust through the prop on a reasonably stock merc magnum engine?
Seems like reversion would be more of a problem at idle anyway, since you don't have the higher velocities and momentum of the intake charge that you get at higher RPM's. Isn't that why you get a choppy idle with long-duration camshafts - partially because of the reversion at low RPM's? I know some of it has to do with the weaker vacuum signal to the carb, but I know I read somewhere that reversion is more of an issue at idle.
#20
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Not for sure, but I would assume it is the exhaust pressure overcomes the solenoid holding it open. I believe the "fail" mode is open & the solenoid holds it closed? either open or closed.. the pressure I am sure would overcome the solenoids. It would also probably damage the internal steel (rubber edged flapper) and burn the edges..... Don't think I want to find out though!!