ZR6 motor adding a supercharger?????

[ski4evr]

thanks mikeski

[jonfo]

These appear to be the manifolds you used mikeski. Was it straighforward replacing them? I have put headers on cars countless times, but havent touched a marine engine.


http://revolutionmarine.com/shopsite...tml/index.html

[TRBenj]

Replacing exhaust manifolds with aftermarkets is straightforward. Just gotta check your hoses- both cooling and exhaust outlet could be routed a bit differently or require a different length. On some applications (especially direct drive), overall motor height and width can grow, so you need to be cognizant of space constraints as well.

As far as hp/$ ratio goes, I agree with Mike- you'll see the least amount of bang for your buck with the exhaust. The weight savings is nice though. $900 is about the cheapest you can get into the game... its easy to spend 2, 3 or even 4x that much. At the lower end of the spectrum are manifold style like Revolution Marine, Stainless Marine, etc. I have a set of Dana marine on our BFN, which are still a manifold design, but keep the 4 runner separate well into the riser. Then there are shorty header style, and then longtube header style. CMI, Lightning and Stelling all come to mind. Stainless is better than aluminum (longetivity) but you'll pay for it.

I dont know anyone who has successfully added a good amount of hp to a MPEFI marine engine yet... but that day is coming. A friend of mine has a GT40 dissected with a 393w build planned- though that project is on the back burner. Plenty of warmed up carb engines running around... its only a matter of time before we start playing in the EFI arena. The question is who wants to be the guinea pig?

[stealth71]

Here's a good article explaining MEFI:
http://www.pirate4x4.com/tech/billavista/MEFI/

Looks like it's a speed density tune.

[jonfo]

That is a very detailed article! Thanks for the link!

[Mikeski]

The installation of the Revolution Marine manifolds was very straightforward and easy. The only tricky part was making some new brackets for the oil filter. The elbows exit into 4" hose so I had to replace the hoses between the elbow and muffler. I also cut some "cuffs" out of the old hoses to leave on the muffler to take up the space between the 3.5" muffler and 4" hose. I thought of some other options but this was my quick and easy solution. Not sure if is hurting the flow but it sure is not helping it.

If I was a bit more ambitious I would replace the muffler with some 4" stainless pipes adding another through hull for true dual exhaust through the transom. I would have then needed to replace my fresh air exhaust with the python style FAE. All of that seemed like too much work for a very questionable return. Plus I hate loud boat motors so I chose to keep my muffler. My motor is nearly silent and I like it that way.

The aluminum manifolds have now been on my boat for over 400 hours and still look as good as the day I opened the box. I like the dry seal between the elbow and the manifold, no more rust trace the stock manifolds seem to get after a couple hundred hours.

I doubt there is that much room for improvement with the older style 350 motors. The factory 330 rating might also be conservative, I have heard that the difference between the 330 and 343 is just being less conservative with the rating but who knows?

With the new LS style motors (ZR6, etc) I am sure there is plenty of room for large horsepower gains. It should not be that difficult to turn the 375HP ZR6 into 450-475HP with modifications to the intake, cam, and tuning for 91 octane in the MEFI controller.