bentherb4

I have done this a couple of times with great results, but this time I am not able to get the full power because I can't do anything with the timing. On the last boat when I set my total advance from 28 up to 32 I gained .15 mpg at a 35mph cruise speed. While this may not seem like a lot I put 3k miles on my boat last year alone and it does adds up. I know other people have stroked MPI engines, and I had one company offer to re-flash my 555 ecms to 383 stroker spec but they wanted 2k for the pair which is a little crazy with no way to really predict performance increase. I am hoping someone knows a way to get about 6 degrees more advance... The engines are 2004 350 mag mpi rebuilt to .30 over and crank switched to a 400 stroker and compression increased to 9.8. My stock ECMs are 865840T01 ECM. There has to be a simple way to trick the computer... Right now it seems like it's only a total advance of 24 degrees at 3200 rpm....

getrdunn

iTrader: (7)

Yikes. Not sure how you'd go about that. I'm sure someone might have a clue. Good luck and will try and research a little myself. A shame not completely utilize those 383's. Always liked that package.

Pliant

Your leaving so much on the table it's a bit scary and im sure those 383's are running very lean. Id dump the 555 and find some new even mefi 4 and a retune would cost that much.

http://www.dynojetcmd.com/cmd_marine_details.aspx Very low cost and well check into it