self-learning EFI conversion

[bashr52]

There have been some interesting advances in self-learning, self-tuning, return-less EFI systems for the street car market lately. I saw Holley has a 2 barrel version that will support up to 300 HP, and 4 barrel that will do 6-650. It would be ridiculously expensive and a waste of $$, but wondering if anyone has ever considered converting their older carb fed engine to EFI using one of these kits? It would remove the need to run a secondary return line back to tank, and would compensate for varying engine loads based on prop size, water conditions, climate, etc. The only thing to figure out would be where to place the O2 sensor for proper mixture feedback.

 

[Bt Doctur]

fuel injection systems do not give you that much more in horsepower and unless your planing on driving the boat on the street it wont work

 

[Bt Doctur]

This has to be the BIGGEST bottle of snake oil I`ve ever seen
http://www.fuelairspark.com/fas/ez-...control-system-mercury-marine-inline-kithtml/

 

[alldodge]

There have been several of the Holley EFI systems installed high HP boats, most in the offshore performance boats. They are not Marine certified that I'm aware of

 

[achris]

Wow, I should have got one of these system before I sold my 180hp 4.3 carbed engine. I could have bolted it on and had 650hp. Ah, but then I'd have to have changed the drive. Alphas shouldn't be pushed over 300....

Now........

What the h** is this 'self-tuning'? ALL electronic injection systems, by their very nature are 'self-tuning', they have to be... 'Snake oil' doesn't begin to cover these charlatans.

Steer a very wide berth around these guys!

Chris........

 

[alldodge]

Now in all fairness they come with bungs and O2 sensors. The bungs have to be installed in the exhaust and as the motor runs thru its paces, the computer will optimize the tune. Same thing Holley is doing and it does work. Slap on a 650HP TB on a 4.3 and after tuning it will not make 650 HP, but will be tuned for optimum capabilities

 

[achris]

Now in all fairness they come with bungs and O2 sensors. The bungs have to be installed in the exhaust and as the motor runs thru its paces, the computer will optimize the tune. Same thing Holley is doing and it does work. Slap on a 650HP TB on a 4.3 and after tuning it will not make 650 HP, but will be tuned for optimum capabilities

I did have my tongue firmly in my cheek AD...

 

[Scott Danforth]

To get EFI to work properly on a motor set up for carbs should require the cam to be changed. the lobe center changes for a better MAP sensor reading if you want to get the most out of the motor.

the increased lobe center actually drops peak HP. as BT Doc mentioned, bolting EFI to a carb motor wont give you any more power. if the carb is properly maintained, it also wont give you any significantly better fuel economy.

but hey, if you want to spend $2400 on a system, by all means, go for it. I personally wouldnt as that is a lot of boat fuel money and beer money to spend on zero net gains.

systems like FI-tech, etc which are low $ actually end up in a lot of trash bins and having the carb put back on.

however to answer the question on how to properly add an O2 sensor to the exhaust: it is usually done with a custom riser or elbow or collector on the headers. it should be placed in the exhaust stream where it can sample the entire bank of cylinders, however it should also be protected from the reversion that happens at low speed. this process is usually trial and error by the OEM

 

[bashr52]

I'm not saying bolting on a system that is capable of supporting up to 300 or 650 hp would increase the power of a 4.3 over stock, just that the injectors and fuel flow in the systems are capable of keeping up with an engine that has those fuel demands. I believe the self tuning aspect just refers to the fact it is not a system that you do not need a laptop to map a custom tune on. Even OEM FI controllers have a base tune programmed in that gives the system an ideal fuel map to work toward.

I've never heard of anyone changing out a cam in order to go from a carb to FI. I did not consider the water inversion that occurs, obviously the 02 bung would have to be located in a position that would be out of the path of any water that may be in the system.

I don't have that kind of money for one of these systems anyway, I just was thinking the fact the fuel wouldn't need an additional return line added, and the system is pretty plug and play would be neat if someone was looking to do a conversion.

 

[harleyman1975]

Custom/Performance mods are generally poorly received here for the reason that once a boat has been modified it no longer matches up to the service manual. Now instead of being able to tell someone that "if A happens then do B to fix it" you now have an individual situation with a whole new set of variables, uncharted waters if you will. I want my boat to be dependable more than anything else and i think most here feel the same. if left in stock configuration then one can open the book and follow the instructions with a reasonable chance of a successful outcome.

 

[Mad Props]

I'm also assuming most of this stuff is not USCG approved, which means if your boat goes boom, forget your insurance payout. Not worth it for a lot of reasons.

Personally, simplicity always wins in my book. I'm going to be doing a rebuild on my mercarb tonight and its going to probably take about an hour. I like the fact that with a properly tuned carb, and a functioning pump, thats pretty much it for your fuel system... Not much to go wrong.

 

[thumpar]

I like EFI but not for increased power. It starts easier and there is not need to do much maintenance to it. Some don't like that when they fail they are hard for them to diagnose or make it home but I have had systems go out on EFI and never had one not run entirely. As long as the system is a simple one they diag easy. I would not one of the ones that are not OEM or one of the newer types that have gone way overboard with sensors.