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Late model Mercuiser ECM Reprogramming

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Old 05-14-2023 | 01:05 PM
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Cool Late model Mercuiser ECM Reprogramming

My friend has a 34' Searay Sundancer repowered with anemic 2020 vintage Mercury Horizon 350-300HP V-drives. 3800 rpm with tabs down just to stay on plane. Definitely lacking torque in the 3400 RPM range. I talked with Procharger and they can quickly assemble the hardware, although to their knowledge nobody has been able to reprogram the late model (approximately 2012 & beyond) ECMs. Does anyone know of a person or company that has "successfully broke the code" OR, anyone working on an alternate laptop programmable ECM with harness adapter to interface with the existing sensors, injectors, etc? About 4 PSI of conservative boost would make this (as well as many other late models) different boats. NOTE: My understanding is that this could be applicable to not only the V-Drive configuration, but any 2012+ late model Mercruiser sterndrive. Anyone with Mr. Wizard like knowledge interested? Thanks for the consideration.
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Old 05-15-2023 | 12:21 AM
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By the time you spend the $$$ and add a supercharger system (of any brand) and get the PCM555 reprogrammed, you would have been better off to sell the current power and install some take out 502mpi's or 496Mags.
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Old 05-15-2023 | 08:47 AM
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Assuming everything is healthy and just a lot of weight on the boat, why not just prop down?
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Old 05-15-2023 | 10:59 AM
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Originally Posted by Griff
By the time you spend the $$$ and add a supercharger system (of any brand) and get the PCM555 reprogrammed, you would have been better off to sell the current power and install some take out 502mpi's or 496Mags.
Rahagel,

This....

Thanks. Brad.
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Old 05-16-2023 | 12:53 AM
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I believe Mark Boos at Precision Marine can program the newer ECMs. It would be worth a call.
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Old 05-17-2023 | 12:18 AM
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sounds to me like you are going to create alot of headache in a heavy sled.
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