502's, cam, slight head work, procharged.

Agree 100% Send it To Precision Marine!!!

carbed or EFI?

Stock efi but thinking about switching it over to carb. I would think that the stock mpi intake cost power even at this level.

fixx
 

WEll your welcome for me to even mention that you have a dyno! and you would be willing to dyno his motor for him...

fixx
 

offthefront on here has stock merc efi with prochargers m3 and with the ecm tuned he ran 92 mph with a 353 formula..remember your forcing air into the intake..also fogducker went from 68 to 88 mph with a m1 and a 454 385 that was freshened in a 22 scarab scx??

I machined about an inch off of the lower intake to eliminate the restriction of airflow under boosted conditions. The long runners are for N/A torque. No need for that with a blower. To save time, I used a carbide tipped router bit to do the radiused edges ( cuts right thru the aluminum) and then finished them by hand. Doing this and a small cam spec change, got me 50 more HP and 200 rpm up top.

See pics

My boat ran good with the stock 502's and the prochargers. Im making some changes and i want to dump the fmu. Mark at precision informed that with mefi 1 i cannot run the 2 bar map so i must either keep a fmu, change mefi ecu's, aftermarket efi or carbs. My first choice would be the dominator efi but its not in the budget. Not sure what to do.

fixx
 

go to painless performance,i believe at the bottom of this pagr you will find 2400001 mefi controller that replaces the old mefi 1 ecm,,comes with cable and tuneing software..call them and talk to a tech to see if this ecm will plug into your harness,,worse case you may need a mefi4 wire harness...i have the number to the giy that designed the software for this system when msd owned it..he said if i ever need any info feel free to call him..
http://www.painlessperformance.com/w...sdignition.php

Holley HP ecu and harness -$1500 delivered. Take you about 2 hours to retrofit. Once you completely price out your other options and compare the capability's, the price becomes very reasonable. It's already been proven that the self tuning feature in the boat can be significantly better then a dyno tune by even the best tuner's. Especially if it's tuned in another part of the country.