Aftermarket tuning solutions for Merc 555
 

I'm close enough to the launch of this to make it public to try to gauge a feeler for retail interest. For some time now I have been working on a tuning solution for the 555 to only be stopped for one reason or another. I finally decided to produce a plug and play solution for the 525 that can be up-fitted to other Merc platforms. This will retain the factory sensors, coils, and injectors reducing the need for extensive swapping on the engines.

My solution is replacing the 555 with a Holley computer and a custom harness. It will also incorporate the cannon plug/14 pin connector. As mentioned before it will utilize all the OEM sensors and electronics helping reduce the cost of the upgrade. I will provide a start up calibration to get started, but for now final tuning will be the responsibility of the end user or installing shop. Utilizing the Holley to NMEA 2000 bridge we will try to maintain Smartcraft functionality, but that is a phase two target.

Thoughts?

I think its a great idea. I did see the alientech and whatever software is available to tune 555s BUT looks like about 20K to buy everything and since its over seas looks like tech support would be a big ZERO on top of fact it looks 10 times more convoluted then mefiburn or holley software. Ive tuned over a 100 mefi 1 thru 4 boats on water, engines on my dyno and mail order tunes but have had maybe 10 people ask about tuning 555pcm so Im NOT will to spend the 8800 eruos or whatever on the tuning software, I t think theres a market for what your doing

Thank you, sir. I looked into the Alientech and a couple other solutions, all required the PCM to be opened and attach leads to the board and dump the bin file. Opening the PCM is a non starter, I think it's a bad idea and it puts me in the drivers seat to tune every PCM rather than allows me to be a solution provider.

I had a piggy back solution but after 18 months the company got bought out by a large capital group and they progress made was scrapped. Grrr

Yep, I seen that cracking the case thing then putting in leads, the whole thing looked like something I dont want to get involved with. Just like installing a holley on a mefi3 boat, same with 555 pcm, the ecu has some value if its NOT damaged it can be sold to offset the cost of its replacement.
Now, a few things to keep in mind though, although holley is easy to tune and navigate, how much time are you willing to give to the customer when they dont have a clue tuning and are having problems? Im saying this as a business owner, lots of people want to buy mefi burn, they will contact me (i dont sell it but its known I tune it) and ask how easy is it? I will ask them,what other efis platforms/ecms have you tuned? if answer is ZERO , I will tell them there is a learning curve and although Bob at mefiburn is a nice guy, hes not going to spend alot of time giving you unlimited support. And Im DEFINATELY not as I have a business to run and need to earn money like anyone else so spending 6, 8, 10 hrs on phone walking somone thru something 1/2 hr at a time turns out to be alot of unpaid time.
so, although Holley is pretty easy to navigate, will you make enough profit off the sale to be able to give enough time to guys with a million questions who like to talk on phone, LOL?

All valid points. My approach to this is most of the tuning and tech related to the EFI will be fielded by Holley as they already have the personnel and tuning classes to assist. If the tech questions come back to the supplied harness then I will be the one to cover those. Ultimately, this is not a novice solution. This is more of an off the shelf advanced user solution or a solution for engine builders and tuners. We (engine builders) have had our hands tied long enough on this package.

Is the Holley approved for marine use?

https://www.holley.com/products/mari.../parts/550-850

Certified to ISO 8846, SAE J1171 & United States Coast Guard Requirements for Ignition Protection & Fire Resistance. Making Sniper EFI the perfect choice for carburetor to marine fuel injection conversions!

HP and Dominator computers are fully potted and socketed.

A HP ECU is what this solution is being built around. Not much need for a Dominator.

Sounds like you are making this work for other merc products that use the 555 too. That would be great. There's a need for this in the marketplace. And there are definitely guys that are savvy enough to make it work on their own.

That sounds like something I would be interested in, how about having a tuning repository like HPTUNERS so people take responsibility for finding and using a free tune so your just the guy that sells the hard parts so you can charge by the hour for tech support.
now that I think about it could you have a unlocked canned tunes for say a stock 502mpi and various other stock mercruiser motors