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CMI Aft Fire mufflers

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Old 10-13-2011, 08:37 AM
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Default CMI Aft Fire mufflers

I am running a 22' Velocity with a 496 HO and CMI sport tubes. I want to be able to quiet things down during skiing and sometimes cruising. I have tried the CMI sound elimination mufflers and they work great, but are a little to quiet for me. I like the CMI Aft Fire switchable tips. My question is do they quiet the sound reasonably well? I have searched, but not been able to find a video clip of them in opration. Any feedback is greatly appreciated. Anyone have a used set of CMI Aft Fires for sale to fit 4" tips? Thanks.
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Old 10-13-2011, 04:11 PM
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Old 10-13-2011, 08:13 PM
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The Aft Fires work about the same as the Sound Elimination AT IDLE, the Sound Elimination being quieter. You MUST open the Aft Fires when underway, basically no restriction in flow or noise when open. I have both; I liked the Sound Eliminations (for 5" exhaust) but they cut too much power. My guess is that they (the bigger 6" dia. mufflers) are good to about 750 HP.
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Old 10-14-2011, 08:30 AM
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SFOcean, thanks for the feedback. So from your experience the Aft Fires are almost as quiet as the Sound Eliminations at idle? I know they do not recommend running more than idle with the Aft Fires closed. However, I would think a stock 496 HO at a 2500-3000RPM cruise would not hurt anything? I have heard some folks run them closed at higher RPM's. I am not sure if the air cylinders could hold the butterflies shut at higher RPM's though.
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Old 10-17-2011, 04:00 AM
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I don't think it is a good idea to run them closed while on plane, but you could be okay at 2500 or so. Maybe call CMI and see what they say.. 920-722-7084
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