Mercruiser 502 dyno run

[Espen Hilde]

Hi!.Just came home after the dyno run, evaluating the
 502mpi magnum Mercruiser
 with procharger kit.We tested the engine first without the charger and the
air fuel ratio  
at part load was not good because of the progressive rate fuel regulator
 not gave the same fuel pressure
 curve before boost as orginal .In the boat this results in sooted
 sparkplugs, high part load fuel consumtion.
 Mercruiser has used a modest 25degries advance at high rpm,that is maybe 
 why we can get away with
 the 5psi boost without retracting the advance. At about 4700 the fuel
ratio
 increased suddely to 11to 1
 this is all the injectors could give at 11.8ms.(previous 10.6ms)This
resulted in a sudden
 fall in HP output.With the procharger(sentrifugal compressor,intercooler)
 the max hp was 575 hp. We started at max fuel pressure at boost at 4 bar.
We lowered the pressure in two steps 0.2 bar at the time and picked up more
hp 
each time air fuel ratio was about 13.2 -1 at max hp.
 We found out that to make this engine run right trou the powerband we have
 to have access to the ignition
 and fuelmaps of the ecm.We allso have to change the MAP sensor to a
 2BAR.And alter the settings innside the ecu to work with the 2 bar sensor.
 any information that can lead us to our target to adjust this engine to
 suite our modification and fit 
 the colder climate in norway is appreciated.
 Thanks in advance
 Espen Hilde