Go Time
12-20-2015, 12:01 PM
Yesterday, I had the pleasure of spending the afternoon at Sanderson Marine with Lee and Clay as they dynoed my engine and set up my Brucato PCU. I thought I would write this thread to share what I learned about the Brucato SVS and PCU on the 225 Promax.
The engine is a 2014 Promax 225 block purchased new and was assembled essentially stock with factory components. The only powerhead mods are WSM pistons, TRD reeds, and 7600 rev limiter with stock program on Merc 824003 and red Merc 40 amp flex plate flywheel. Heads are stock/uncut. Base WOT timing at 23-24 degrees BTDC.
After realizing that I forgot to tell Lee that the lower unit was a 2:1, which we found out the hard way (rev limiter not actuating correctly…or so we thought), we performed a base run of the engine before SVS. In stock form, the engine dynode a best of 240-242 hp. The stock ECU was very rich and stumbled a bit when rapidly hitting the throttle. Some of this was corrected by switching plugs from NGK BUZHW to NGK BR8HS. This made a big difference in acceleration and crispness of the low end, but no effect on max hp.
After installation of the SVS, and the Brucato PCU, Lee and Clay made many pulls, changing the fuel curves richer and leaner, and varying RPM ranges to help clean up the bottom end. Clay then developed a custom fuel curve from all of the printed data obtained during the dyno runs. The program was then loaded into the PCU, and a couple of final data runs were made. The results were a maximum of 250-252 hp at 7400 RPM and there was far crisper performance in the low to mid ranges.
The whole process probably took half of the engines life! (just kidding) The engine had never been to 7400 RPM that many times. It’s a little unnerving sitting next to it on the trailer and hearing it run like that….actually, it was awesome. Big thanks to Lee and Clay for making the while process a heck of a lot of fun, and getting it right. And thanks to my lovely daughter for typing this up or it would have taken me all day…
The engine is a 2014 Promax 225 block purchased new and was assembled essentially stock with factory components. The only powerhead mods are WSM pistons, TRD reeds, and 7600 rev limiter with stock program on Merc 824003 and red Merc 40 amp flex plate flywheel. Heads are stock/uncut. Base WOT timing at 23-24 degrees BTDC.
After realizing that I forgot to tell Lee that the lower unit was a 2:1, which we found out the hard way (rev limiter not actuating correctly…or so we thought), we performed a base run of the engine before SVS. In stock form, the engine dynode a best of 240-242 hp. The stock ECU was very rich and stumbled a bit when rapidly hitting the throttle. Some of this was corrected by switching plugs from NGK BUZHW to NGK BR8HS. This made a big difference in acceleration and crispness of the low end, but no effect on max hp.
After installation of the SVS, and the Brucato PCU, Lee and Clay made many pulls, changing the fuel curves richer and leaner, and varying RPM ranges to help clean up the bottom end. Clay then developed a custom fuel curve from all of the printed data obtained during the dyno runs. The program was then loaded into the PCU, and a couple of final data runs were made. The results were a maximum of 250-252 hp at 7400 RPM and there was far crisper performance in the low to mid ranges.
The whole process probably took half of the engines life! (just kidding) The engine had never been to 7400 RPM that many times. It’s a little unnerving sitting next to it on the trailer and hearing it run like that….actually, it was awesome. Big thanks to Lee and Clay for making the while process a heck of a lot of fun, and getting it right. And thanks to my lovely daughter for typing this up or it would have taken me all day…