[Tineoidea]

Hi. My Name is Noah, and i am from Switzerland.

I am Currently writing the BOM for a Project.
I will modify a Chrysler Slant Six 225 (3.7l inline six) to EFI with port injection. After reading the Speeduino documentation and consulting the forum, i am under the impression, that 6 Cylinder full sequential injection is not possible yet.

On one of my many google searches i found a board that claims, it has 6 injector and 6 ignition channels. (But they dont mention if they can provide full sequential)The manufacturer claims to use modified Speeduino code.
https://sparkefi.net/ecu/31-speeduino-s ... o-ecu.html

As i have read many times, that more than 4 cylinder full sequential is not possible, i am sceptical. I also was not able to find any reviews.

Has anybody ever heard about, or used this board?
Any thoughts?

Not having full sequential wouldn'd be a deal braker.


Thank you guys for your work. I love the idea of the speeduino project.

[dazq]

Welcome!
Actually More than 4cyl sequential IS possible.
BUT.
The mega has 9 timer channels available.
Each injection ,ignition ,vvt and idle output need a timer.
Soooo in theory you could have 6cyl sequential spark, three channel grouped fuel. But no idle or vvt control.
Or variations there of (you get the idea, mix n match sort of thing)

Last I saw they didn't have a board type in the official firmware so this is likely what the modified firmware is for . This means you have to either always use their firmware or if you want to use official releases then you would need to modify and compile the firmware yourself (which is not particularly difficult just a pest as it would need doing each time )
Have you looked at other boards? Take a look at the 3rd party section in the wiki for other options to the official board types.

[PSIG]

Welcome! There may be equivalent performance options. What specific advantages are you looking for with sequential injection, and for sequential ignition?

[Tineoidea]

Thanks for the replies.
The setup i am shooting for is single smart coil through distributor. Port injection, full sequential if possible. Iac would be nice, but is not a requirement.
I will do some research on other 3rd party boards.

My goals for this build is achieve maximum fuel efficiency. And if there is performance to gain, i wont say no.but efficiency is the important goal. If i got the injection/ignition part sorted out, i might add a low pressure turbo.
I will start with injection only. If that works, i will add ignition. And if that also works, i will add the turbo.
Changing to much at the same time doesnt seem wise, as i am new to Fuel injection technology.

[PSIG]

My goals for this build is achieve maximum fuel efficiency.
…
And if there is performance to gain, i wont say no.but efficiency is the important goal.
…
I will start with injection only. If that works, i will add ignition. … Changing to much at the same time doesn't seem wise, as i am new to Fuel injection technology.

Understood. Know that fuel efficiency is a performance. All performances are based on efficiency, from power to economy and even emissions. Efficiency is required and may be applied specifically to any of the performances. The ability to apply efficiency selectively and as you determine, is the largest benefit to fully-tunable control.

Also know that both fuel and ignition must be employed to achieve efficiency, and rely on each other. So, as you may plan to phase fuel-only, then ignition, you will need to eventually employ both in order to achieve the efficiency you seek.

Efficiency improvements are cumulative. The conversion to fully-tunable control is the largest gain, in order to apply your efficiency tuning to your goals, rather than factory or other goals. Features and functions such as sequential can also be beneficial, but to a much smaller degree. It is a large benefit to convert to full control in any form, even TBI or paired/batch, as the large gain and learning curve can begin. As experience and familiarity increase, the additional capabilities may be added and employed effectively.

My meaning is if there is a choice between delay, cost or effort to an added function, or simpler and quicker conversion, I suggest the quicker path for fastest gains, knowledge and experience. Add functions and complexity as you see evidence for them, and how to best accomplish them with the new knowledge you have gained with simplified control. You may and probably will find that your current vision will change substantially with that new knowledge. Get there as quickly as you can, so you know exactly how to move forward most effectively.

[WesKampProductions]

@Tineoidea can u tell me what crank trigger sensor you are using for the sparkv1.1? I bought one who ever I cant seam to get it to see a crank signal.. also can you share how u have yours wired?

[Tineoidea]

@WesKampProductions:
I am still in the early phases of this project.
So i havent wired anything yet. The crank trigger i want to use is salvaged from a dodge Ram 5.9 engine.

@PSIG

I opted to order an assembled speeduino 0.4.3c board. Using an unknown board with modified firmware, that might not get properly maintained seems to be a bad idea.
The main reason i would like full sequential is
the planned injector location. I want to install the injectors directly into the head. This has been done, and gives the injectors a nice straight shot at the intake valves

But placing the injector as shown has the following problem:


As you can see , some of the the injected fuel is bound to make its way torwards the intake manifold. If ran in paired injector mode, some of the fuel will puddle up in the intake. That would be my guess.
But this might be a non issue. Because the exhaust is on the same side as the intake, the manifold could get hot enough that some of the puddled up fuel will be vaporized. I am not sure about that.

If i interpret dazq s post correctly my setup could work with full sequential injection.
6 timed channels for injection, 1 for the ignition through the distributor and one for an iav (maybe only a solenoid is possible?)

When my board has arrived, i will cobble together a bench test setup and see, if i could get everything to work as intended by me.

[PSIG]

The main reason i would like full sequential is
the planned injector location. I want to install the injectors directly into the head. This has been done, and gives the injectors a nice straight shot at the intake valves
[image]

My intent here is not to "split hairs", but post general concepts. Your injector placement is fine, and should work well, generally. While the intake valve stem base is commonly the target, it should be close enough to get some useful benefit. Typically the aim is at the stem base as the area between the stem and about 2/3 to the seat edge is the hottest part of the valve.

This is the valve heat distribution. While these are exhaust valve temperatures, the intake heat distribution is similar, and temperature is not so extreme. As the heat is dissipated by the valve seat and stem, you can see the target for fuel spray:

But placing the injector as shown has the following problem:
[image]

As you can see , some of the the injected fuel is bound to make its way torwards the intake manifold. If ran in paired injector mode, some of the fuel will puddle up in the intake. That would be my guess.

Targeting the port floor near the valve seat may not be optimal, but as it is an area the valve heat sinks, is still quite hot. And as you say, the exhaust is nearby, so it is not cold there.

It will certainly still run 'fine' as all fuel will eventually be vaporized from the walls and into the air-stream - perhaps not all of it on the on the next intake cycle, but will average across multiple upcoming cycles. You can imagine how this would change tuning of transitions such as Accel Enrichment, if more of the fuel sticks to the walls on the next rev.

This is a good place to remind readers that injector spray angle can be important in this type of vaporization scheme. The intent is to get as much of the fuel on the hot valve for rapid vaporization as possible. A common misconception is that stock injectors firing on valves often have 'old-technology' pencil or narrow spray patterns, and switching to a wider spray or fog pattern inject or will be an improvement.

Unfortunately, this defeats the purpose of the scheme, and vaporization effectiveness and efficiency is reduced, with more fuel missing the valve and wetting the cooler walls. The tight spray patterns are intentional. Multi-hole or wide-pattern injectors are often a step backwards. Again, it will apparently run "fine", but cannot be tuned quite as efficiently as the correct injector pattern for the scheme.

But this might be a non issue. Because the exhaust is on the same side as the intake, the manifold could get hot enough that some of the puddled up fuel will be vaporized. I am not sure about that.

There are far too many factors in fluids and dynamic flows to predict accurately, so we simply apply the best general principles we can. An example of this could be quasi-sequential, injecting twice per-cycle on each cylinder. The benefit to your injection scheme is one injection of half the fuel much earlier than the normal sequential squirt, permitting far more fuel dwell time on the hot parts.

Following is a second injection that also contains corrected fuel from data gathered in the last crank rev (corrections, acel fuel, etc). They combine to provide less lag, greater vaporization and sharper tunability, and why some OEMs are using this general scheme today. Everything is a compromise, and quasi has other concerns, such as injector size and latency (dead-time).

No, it is not necessarily "better" than another scheme, but has other advantages, such as being accurate using only paired injectors (3 INJ channels on a 6-cyl). This has other benefits in the control, wiring, and other simplifications while gaining most of full-sequential benefits and others sequential can't do. I'm not saying to use quasi, but simply getting the info out there, as yet another example of more than one option to achieve desired results. Use the best you can for the specific application and goals. All choices are yours. Use what you can wrap your head around and is effective for you.

[Tineoidea]

Well. What you wrote makes a lot of sense to me. Maybe semi seq could be beneficial in this particular set up. I like the idea of using one of the many design flaws of such an old engine to my advantage. I think i will look into this.

Thank you a lot.