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Exhaust Gains

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Old 02-28-2008, 09:42 PM
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Originally Posted by R Addiction View Post
Or your dreammeter is not accurate
come to think of it my dreammeter needs to be re-calibrated this winter
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Old 02-28-2008, 11:50 PM
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I was thinking of changing my e-top CMIs to big tubes on my 540s, but after looking at the price I decided to wait until I really needed to change. After talking to CMI directly, even they said I probably wouldn't notice the difference.
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Old 02-29-2008, 01:06 AM
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What about Dana marine or EMI exhaust for the HO ?
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Old 02-29-2008, 09:49 AM
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First of all, the stock exhaust on a 496 isn't all that bad to begin with. Especially if you have the aluminum manifolds (as my 03 does). I picked up 2-3 mph with my Baja Hammer when I changed from stock to GIL, but the stock 7.4 exhaust is junk, so anything would have been an improvement.

I'll asnwer your question this way - I've modified everything from the block to the K&N intake filter and I'm running slightly ported stock manifolds.

Hey Clay, when are you going to "blow" these engines?
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Old 02-29-2008, 10:16 AM
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Most of the gains from switching 496 exhaust to aftermarket is from the removal of the "turbulators" that reduce the outlet about an inch. Supposed to be worth 10-12hp just for removing them. Do a search in the tech forum, there are a couple threads there. Doesn't cost anything to try.
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Old 02-29-2008, 11:48 AM
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Hey Clay, when are you going to "blow" these engines?
Hey! I love a good supercharged engine. You just need to make sure that everything else will stay together, i.e. forward gear, full hydo-steering, etc.

I plan to leave my current Bullet alone. I spend most of my time with the key off anyway!

In the next couple of years I will step up to either a 35-foot Playboy or a 38-foot Topgun. I will have super-charged engines in my next Cig!
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Old 02-29-2008, 12:18 PM
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Removing the turbulators wont do anything for the feel of your boat. 8hp on the dyno, yes. Seat of the pants and GPS, no......i dont consider 1mph to be anything worth writing about. Would i go ahead and remove them? Of course. Its too easy. The aftermarket exhaust will get you mid twenty hp. Some of that from no turbulator and the rest from better flow. CMI's do sound great on the HO's, but I would go for the gusto and get the intake done too. Aluminum raylar cylinder heads, roller rockers, and cool gap intake for sure....those three with cmi's would be a nice little 500efi-like package. Dont waste money on just exhaust for these motors.
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Old 02-29-2008, 12:30 PM
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We are a lightning header dealer (Amongst other brands) and gave had good luck/worth while gains on the 496HO. With that said, good results/gains are 2-3MPH and a few hundred RPM.
Do they work better than stock? Yes
Do they sound better than stock? Yes
Do they add performance? Yes
Are they worth the investment? That's up to you...

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Old 02-29-2008, 12:51 PM
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1 free mph sound good to me. They sound better too. I like the Raylar package, it's a well engineered kit, but combined with the price of cmi's you'll spend $10-12K per motor for 75hp. 525's are about 500pshp, and 496Ho is 425pshp. The 650 kit might be more worth it. I would lean toward whipple for the most bang for the buck. If you can make the motor live under boost. I've been hearing good things about that lately.
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Old 02-29-2008, 12:54 PM
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1 free mph sound good to me. They sound better too. I like the Raylar package, it's a well engineered kit, but combined with the price of cmi's you'll spend $10-12K per motor for 75hp. 525's are about 500pshp, and 496Ho is 425pshp. The 650 kit might be more worth it. I would lean toward whipple for the most bang for the buck. If you can make the motor live under boost. I've been hearing good things about that lately.


no....the 496ho is 425 crank hp.....even worse
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