Would it be worth it?? Exhaust swap
 

So I have been doing a lot of reading on exhaust systems as I'm always looking for upgrades on things...I have a 540 with a 14-71 blower fuel injected and I got to thinking about exhausts. I currently run CMI E-tops and they work perfectly fine no leaks or anything but I got to wondering if swapping to stainless marine gen 3's would be worth the upgrade? I have read that they are good for a power bump on engines but couldn't really find anything on if they would be a worthwhile upgrade for me or not? Looks like the kit is around 7500 bucks plus transom mods as I run 4" tips now that are dry to the tip and I would opt for either 4 1/2 or 5" tails with the new ones and would convert to the dry tip style beauty rings and gaskets on the transom vs the rubber bellow connection like I have now as I've had them fail in the past.

Could probably sell my e-tops/tails for 2kish maybe...they are powdercoated black and the tails are wrapped with exhaust wrap as I didn't want the shiny stuff on my engine...just personal preference.

So basically if they sell...would be a roughly 5-6k upgrade plus all my time modding my transom which is whatever...not a big deal.

What's everyone's thoughts? Worth the upgrade?

I am not the smartest guy on here, but I would not spend the time and money to change out your CMI's. At the same time, I would probably never pay 2k for anything used CMI. The elbow tops are probably the most reliable thing CMI makes, so that's a big plus. You know more than I do about blower motors, but I do know that blower motors handle less than optimal exhaust better than HP NA motors do. AND just say you get into your 40's and say to yourself I don't like crawling in bilges anymore and I just want some nice low maintenance big blocks. Now, the 5" system is less than ideal. My vote is keep it as is.:)

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Stainless Marine Gen 3 is where it's at!!

What is the ID of your current runners ? what HP ?

E-Tops rarely fail. I know of two sets that are 20 and 17 years old and still no leaks. If it ain't broke...

I doubt you’d even see a speed increase. 2k plus all the other screwing around worth it for zero speed increase?

According to CMI's website....1 7/8" primaries....estimated around 950-1000 hp. It dynoed 993 previously but have changed tunes, currently changing EFI setup, and upping boost 2 lbs.

Like I said I have no issues with the current headers at all just was seeing if I could expect a difference by switching? Seems like so far from the posts they won't make much of a difference if any?

Always looking for any kind of upgrade and read reports of HP gains on NA builds by switching but wasn't sure on a SC application?

Thanks for all the replies so far!!

Also that OL is ridiculously bada$$ by the way!! hahaha

OK Steward settle down.:hitfan:
The only advantage I see is easier to install .
you ROI in terms of HP is extremely low here .

LOL thanks for the insight Dan :throw::lolhit:

Agreed! When my CMI's fail (and they will if you believe the interwebz) that's what's going on the boat no question since I'll never have to worry about them again. My big tube CMI's sure are pretty but reliability and peace of mind go a long way... Besides that, I can do both sets of SM's for the price or less of one set of CMI's.

My SM are dry to the tip with external water dumps and they’re louder than any CMI I’ve ever had.

Agree with 302 Sport, CM Gen 3 is where its at. Sound Great!
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I don't see any headers in that pic hahahaha

Let's just say for the future...If I were to switch from my 540 to a 572 or 588 whatever and up boost some more....would they be a worthwhile upgrade then?

I guess what I'm asking is at what point if any would they make a justifiable upgrade over my current e-tops? Or would it only make sense if I had a huge NA mill?

The biggest plus about the stainless marine setups is they don’t ruin engines by leaking. To me that’s worth the price of the engine…

Is there any dyne results on the GEN 3's?

Years ago, on OSO there were numerous guys with big 1100+ hp blower motors that always claimed the SM Gen 3 outperformed the CMI's on the dyno.

E tops or Long tube?

When we flow tested those headers 2 runners were 296 cfm and 2 were 248 cfm, they work but not optimal. I think a 2.25 primary would make a difference. But that's just my opinion.

I had em make me a set out of carbon fiber .
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With these there`s no different length runners, I would think headers would scavange and flow better . I do like no headeraches and just the ease of install is super nice but my headers were leaking so I had to make a change ..

That’s awesome!! You hydro dip them?? If mine ever have to come off the engines I’d definitely be interested in doing that. How many people have asked if they’re carbon?? Any pics installed?

yes , hydrodipped.
Looked cool but it eventually peeled from the heat at the bottom but couln`t be seen in the boat.

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I hated those headers but they did look pretty bad ass.

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CMI 316 stainless Big tubes fail?

What is their weak link? Seawater stays in the tubes, eventually eroding them?

Do CMIs have replaceable zincs?

Hot salt water is not good on 316L. 304 is even worse, even at low temps.
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