How do I get to approx. 400 hp on the Mercruiser 383 MPI reman engines???? Im sure this has been discussed to death in here but I don't find anything specific for the MPI. Seems to be more minded on the carb models.

I cant get the engines in a bench for testing and remapping (im in Europe....) but I can send the PCM555 to Whipple for remapping. I was planning to do this to get it configured to 91 oct (we call it 95 here) but before I do this I was thinking I could put in a new cam and possibly a new intake manifold? I hear this is where these engines seems to be loosing out some power? nothing crazy, all I want is 400 hp each side so I can keep my 23" Rev4 props but get from approx. 4900 rpm to 5200 plus if possible. Also I need to crack the 70 miles mark (im currently 67.....) im not looking for higher numbers really and certainly not willing to go BBC. I love the weight balance in the boat as it is now and I get on a plane faster than my brothers Outlaw 25 with 550 HP Raylar. BTW im running twins in a 28 Pantera. Also posted some refurb pictures in the Pantera forum recently.

Personally I think the exhaust systems are not a must but I could be mistaking. I just don't see the value for money but obviously like the looks! With thru hull exhaust already I don't think a gain would be in there. Basically I was thinking "a" cam of some sorts, intake and throttle body from Edelbrock. They seem to have something that would fit but if this is "plug and play" I don't know, nor if this would bring me to where I want to be.

Any ideas?

Knallan,
I just built a 6.2 carbureted, and Bob Madera from Marine Kinetics was more than a great help, very knowledgeable and fun to have conversation with (you'll learn a lot).
I would give him a call, he'll put you where you want to be, just be ready with pencil and paper.

Jody

I got 400 HP from mine with a new Edelbrock intake, mild head porting of the stock heads, roller rockers, cam from Marine Kinetics and to be safe got some stainless risers from Hardin Marine to compliment my GLM manifolds. If I did the throttle body, my engines ran 411 HP if I remember correctly when my builder tried one. This is also on 87 octane. Left some power on the table there too.

Here's a ton of information:

http://www.offshoreonly.com/forums/d...-new-post.html

Captain Yarrr you seem to have build just what I had in mind. Can you share any details? I see you mention Edelbrock 29135 for the manifold Super Victor EFI for E-Tec/Vortec Heads (BTW is it necessary with new fuel rails?). I have a guy that can do the porting, and all the manual labor I do myself:-) For the roller rockers and cam can you share specs for me to order?

I see in your thread also that you might be considering the 1100cfm 90mm throttle body? surely this would make good sense but im not sure how to work around the IAC and TPS though. Something to dig into.

need more input here!!! anyone?

Anyone out there that can help me on the cams???

I would talk to dustin at whipple and see if has done a combo with a remap and cam swap,the cam can really throw off the fuel map and there is only a few people around that can tune the 555,if no one has done a combo with the 555ecm i would get a reflash from whipple and put on some aftermarket exhaust,probably good for 30-40hp or so

Sorry I forgot to get back to you on this thread. Call Bob at Marine Kinetics. He'll set you up with a good cam for your setup.

like Captain Yarrr I got 400hp out of twin 383's. actually his and mine where dyno by the same guy, Bob Lloyd at Full Throttle Marine in Spicewood Texas, Northwest of Austin. Another that might can help with ECM is Aftermarket Marine in Kenner, Louisiana. The builds are similar but lil different. Mine started as 2001 twin 300hp 350CID MPI in a 29Scarab. Ran 68mph stock, Has run best at 73mph to date. went from 23p mirage plus to 25 mirage. still playing with it ,,,,,,

If you were to "mirror" CaptYarrr's engines, Mark Boos has the ECM 555 tune that would work. Install some 02 sensor bungs and double check the A/F ratio's after you're done.

Bob