Lightning -vs- CMI Headers on 496HO

3163 Views 13 Replies 9 Participants Last post by CC, May 24, 2008

MattBMiller

Discussion Starter · May 19, 2008

Has anyone seen dyno numbers for lightning headers posted anywhere? They're about half the price of the CMI's for my 496HO and considering I only boat in fresh water, might not be a bad option. I do not know where the water enters the exhaust on the Lightnings though.

Matt

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Marmaduke

· #2 · May 19, 2008

I think CFM might have some data try and shoot him a PM.

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SC288

· #3 · May 19, 2008

Headers

The link below will show some of the pictures that I took of my Lightnings. I too thought the same thing about the price and obviously decided on the Lightnings. I was very pleased with the quality. I would think that you would pickup around 40 HP. Also the water mixes near the end of the tube.

Mike

http://www.sunsationboats.com/forums/showthread.php?t=1463&page=5&highlight=winter+projects

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SC288

· #4 · May 19, 2008 (Edited)

Headers

Here is a link for the 496 headers. They claim on a 454 Mag 365 HP that going from the log style manifolds to their headers that you will gain 45 HP. I would think that you would pickup around that.

http://www.cpperformance.com/detail.aspx?ID=6300

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Kidnova

· #5 · May 19, 2008

CMI's are good headders but they seem to have a reputation for failure at welded joints after a while. That can lead to disaster if water is ingested

However, I read somewhere that they will last longer, if properly supported. Who knows

Although Lightnings don't have full/32 inch primaries, personally I'd chhose the Lightnings over CMI's. Question is, how much more hp/tq would you get with CMI's as opposed to Lightnings. And is it worth the extra cost.

Bang for the buck, I think KE's are the best choice

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FstBoats

· #6 · May 19, 2008

CMIs ALL THE WAY!

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Canada Jeff

· #7 · May 20, 2008

I doubt the extra cost of the CMI's are going to yield any more hp than the lightnings.

As for your question about where the water enters the lightnings, its the same as the CMI's and many others, throught the bottom.

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dominator scott

· #8 · May 20, 2008

No problems with my Lightnings. Love em.

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waterboy

· #9 · May 20, 2008

Luv my Lightnings!

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CC

· #10 · May 21, 2008

Don't get your hopes too high. My CMIs added MAYBE 1/2 mph. No way did they add 40+ hp to a stock 496 HO. Also the Q&Q kit is poorly engineered and will work only at idle without mods. With mods mine is still only good in quiet mode to 3,500 rpm. That said, I don't regret dropping the 5g on the best headers available because I plan to redo my motor in two years and SC it. Then those headers will do their job. Do you have the factory aluminum exhaust on your 496? If so, it is a very free flowing exhaust system, probably capable of flowing up to the limits of the stock heads. Has anyone seen real speed increases by just bolting on CMIs?

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FstBoats

· #11 · May 23, 2008

CC said:
Don't get your hopes too high. My CMIs added MAYBE 1/2 mph. No way did they add 40+ hp to a stock 496 HO. Also the Q&Q kit is poorly engineered and will work only at idle without mods. With mods mine is still only good in quiet mode to 3,500 rpm. That said, I don't regret dropping the 5g on the best headers available because I plan to redo my motor in two years and SC it. Then those headers will do their job. Do you have the factory aluminum exhaust on your 496? If so, it is a very free flowing exhaust system, probably capable of flowing up to the limits of the stock heads. Has anyone seen real speed increases by just bolting on CMIs?

Almost a 4MPH Gain in my Sunsation SSX
went up 1 size Prop. Stock Prop Im in the Rev Limiter BAD!

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