EFI kit basic.Whats available
 

Prefer a kit capable of 700hp without an oxygen sensor.In the past whenever i've used sensors they foul too
quick.
Anything available

That would eliminate self tuning, and make it more difficult to tune in general.

Its my understanding that the Holley system uses O2 sensors, but once tuned the sensors can be removed. ICDEDPL would know more

Most stand alone systems can run in open loop (no 02s).
What is your budget?

The whole point of EFI is Closed loop compensation using an 02 sensor. Otherwise what`s the point ?
find a way to make your 02 live. It`s not going to foul out with EFI , water is your only enemy

This may save the O2 sensor
Innovate motor sports 3729 heat sink bung extender hbx-1

Don't have a budget.
By fouling I meant moisture,might just have to go with O2 sensors.

So the Holley system?
I saw MSD make one.

https://www.offshoreonly.com/forums/...-everyone.html

you might find this link interesting,I did

You must have the O2 for tuning. Once done you can generally operate without.....BUT...I highly recommend keeping them active as is a great feedback tool on engine health. Key is having a well engineered sensor location.

I limit my fuel compensation to 15%. so if a 02 sensor takes a dump I`ll know because I can see the compensation percentage on my Holley screens. It`ll peg compensation at 15% but won`t blow anything up .

Location is key, haven't lost a sensor in over 20 years.

Who will be doing the tuning? Ask what ecu they recommend.

I personally don't use 02 correction on my street car, it runs in open loop under load. USUALLY when an 02 sensor goes bad, it shows a lean condition. If using 02 correction, it will dump to much fuel which would be safer than pulling fuel. A 15% correction is around 2.0+/- a/f on a typical boosted engine (12:1 would be 10:1 or 14:1 on a false 02 reading).

I would go with a Motec ecu personally if you or your tuner is comfortable installing/ tuning it.

How about the Holley sniper or the Fast one?

If you run dry pipes I assume then there is no worries about loosing a O2 sensor? (granted do something like ICDEDPPL also).

These things have been used in the auto world forever, and the same basic tech is used in industrial apps all the time. And we put those in some NASTY environments.

Holley hands down. Use the HP or Terminator. You tune it via O2 I initially then shut it down to straight speed density. And you cannot beat the safety nets. Knock retard, oil pressure failure ignition cut, iat timing retard, etc. Anything you would want to tune your boat and keep it safe. Very very good system. I have ran it on a turbo LS for years now and is flawless. Currently setting up two more on my boat. Btw you can tune it without the O2 if you choose.

Letting it tune with O2 then locking it seems safer. An O2 failure seems more likely than an injector failure. But if it goes rich in the o2 failure scenario, then maybe it isn’t a big deal.

They are cheap now and you could replace them yearly.

If you’re not constrained by budget I’d go nicer than the Sniper.

One issue with the Sniper is a fuel smell at idle. I went looking for a leaking line but saw on the internetz that it is an issue. Ironically, the reason I went with EFI was to eliminate the fuel smells.

I'll throw out,big stuff 3

Wet tails.
Always in salt on a lift.Fresh water flush.
I'd guess what kills them is sitting on the lift,ocean front and open tails.

I dont have EFI (yet) but adding Weaind 177 blowers so I want to know A/F ratio. Had some aluminum wedges made so I can put O2 sensors between Gil exhaust manifolds and pipes. I run closed cooling and water dumps back into exhaust pipes 4 feet away from motors and down angle. I'll let you know if they live or not in a month.

Weiand 177's.Destroyed a couple of motors with those when I was young.
EFI and O2's will be your best friend because boost isn't.