Does Neptune have this capability?
I’m wanting to use the stock fuel system (injectors, rail, pump, tank, etc) for low loads and have a secondary fuel system (separate injectors, rail, pump, tank, etc) engage while the loads increase (boost increases).
This is so I can continue using 87 octane for normal driving and E85 for when I feel like moving a little faster.
The actual plumbing of the secondary fuel system isn’t a concern. I’m just trying to figure out how to control it.

Maybe I could use the nitrous settings since its activation can be based upon engine loads, RPM, speed, etc?

 

Not really. You're limited in that area since the ecu hardware remains stock. The NepTune/Moates hardware only adds tuning capability to the stock setup.

You'll need some way to drive the additional injectors.

 

How does E-manage do it then?

 

Emanage has its own native additional injector driver. NepTune/Hondata/etc simply replaces and emulates the stock ROM, enabling you to add soft features. If you were actually to use one of the outputs on them, you would just be switching injectors on and off with no actual control over the pulses.

What you're trying to do seems like a lot of extra work and system complexity for not a ton of benefit. If you are really that committed to running a dual-fuel setup, maybe the best solution would be separate tanks and pumps to a single rail and set of fuel injectors. You could use map switching and a switched output to flip flop between fuel sources and tables... Theoretically.

Using modern injectors should afford you the flexibility to handle that on a single set.

 

If I went with a dual fuel setup, I'd like the transition to be blended for smooth operation.

 

With Neptune, the switching between fuel maps can be as easy as pushing a button or even easier by setting it to switch maps when certain requirements are met (minimum Rpm, load, throttle position).

 

You can use a fuel sensor to signal a map switch, but there is no map blending available. If you need more advanced functionality like that you should probably be looking toward a true standalone EMS like Haltech, AEM, etc.

 

x2 You are going to have to go with a stand alone EMS if you want a true 2 stage fuel injection setup. AEM, Motec or MegaSquirt III, these EMSystems can allow control for up to 12 injectors, fully sequential, both fuel and ignition.

I am bench testing my MSIII on a 4 cylinder two stage fuel injection system right now. I have ITB's with two banks of injectors. The MSIII has a few different configurations that you can choose from for blending the two banks.

 

I had an idea like this and figured out a possible way (not ideal, but could work) of controlling 2 separate rails/fuel systems with the s300. The injector driver's acceptable range of resistance is 8-12ohm's.
the stock injectors are ~12ohm.
In order to trigger a 2nd injector off of the original signal you need to keep the total ohms between 8-12. The 2nd "circuit" (injector/resistor) will need to total approximately 35ohms in order keep the total ohm the injector driver sees above 8ohms. (ie a 10ohm injector + 25ohms of additional resistance).
Run the common (+) of the secondary injectors to a relay that is triggered by one of the s300's nitrous/aux outputs.
Then use one of the other s300's nitrous/aux outputs to trigger a relay for the secondary system's fuel pump to turn on a bit before the 2nd set of injectors are triggered on the other nitrous/aux output. Tune the fuel/ignition maps according to when you activate the 2nd set, as total fuel requirements will be drastically different. Make sure to apply strict lean protections within the software. This would be mean that both sets of injectors are operating.
You could use the 3rd nitrous/aux output to trigger a relay to disconnect the primary injectors (+) feed, while simultaneously bypassing the added resistance on the secondary circuit if you want to run solely on the 2nd set when WOT/high boost.
This is just an idea I had and I've just been too lazy to try it.

 

In theory that sounds like it would work. However, that is a shyte load of work considering there are stand alone EM units for around $500 that already have everything you need to fully control a 2 stage fuel injection system.

 

True. Was just an idea I had floating around for Hondata. The only staged injection system I've tuned was running AEM.

 

I agree 100% but adding to that, I don't see the value in it when there are huge injectors out there that can still maintain a reasonable idle. Staged injectors are knid of old hat for most applications, IMO.

 

The op was wanting to run 2 separate fuel sytems. One for 87 octane, one for e85. And be able to transition between the two at wot or a certain load.

 

Right. Sorry, I thought you were talking about strictly staging injectors on a single fuel system. I understand what OP is going for... still don't see the value in it, aside from "hey, look what I pulled off" factor.

 

You're overly complicating that. I can't imagine you're pushing more than 900hp and would be remotely close to needing dual MPFI systems. A meth injection system would be much cheaper and less of a nightmare to tune. Xenocron has staged meth injection systems for like $400, and they work very well.

 

Ok, lets put it perspective for people. Say for instance you live in a town where the closest e85 station is 150+miles away. You daily drive the vehicle or like to cruise it around, but you're close to or above the detonation threshold of the 91 octane with your build. You occasionally go the place where the e85 is sold and fill up your second tank. You dont want to waste the e85 just cruising around.... makes good sense. Methanol is a good option. Although it is much more expensive than e85

 

It's still irrational to use such a complex and obsolete system for such a simple problem. Even direct port nitrous foggers are obsolete.
Nobody said you have to use methanol in a meth injection system. you can use E85. you can use water. you can use heet, or windshield wiper fluid. its only purpose is to curb detonation, which it will do if it's tuned properly.
I'm one of maybe 5 tuners here who have extensive experience tuning meth injection, I'm telling you, there is no reason to use two MPFI fuel injection systems.