My Megasquirt EI Installation

Spring has come a bit early to the Midwest and I was able to finish my Megasquirt EI installation that I started in December. These are self-built and relatively inexpensive. No learning curve, as I have built one in the past for my air cooled Porsche (fuel injection and ignition in that case). I ended up using an old slick mag for the pickup. I left the shaft in place and fabricated a 6-1 wheel using magnets and a hall effect sensor mounted on a custom bracket where the points used to be.

I programmed two timing curves, one for ROP operations and one for LOP operations and installed a switch next to the mixture for switching between the two.

We had relatvely low ceilings and a fair amount of chop today, so didn't get to do much testing, but had a few observations. I can now easily get my idle RPM down into the 500's. This made a BIG difference in my landings (FP prop). When I chop the throttle now, I can really slow down in the round out and flare. Examining the logs, it looks like I picked up almost 100 FPM in my initial climb. I didn't get to do any really speed tests yet, however, at 2500' and LOP, when I hit the switch to go from 30 - 35 degrees advance, I picked up almost 40 RPM, which should be about 5 MPH on my setup and on top of what I might have already been getting, if anything, by being at 30*

I can't wait to get to 8000 feet and do some speed runs to see how much improvement I got. I will also do some comparisons against a 25* advance.

The most interesting benefit was the tightening up of my EGT peaks. With two mags, the spread was pretty ugly in most phases of flight (I have a carb). The EI made a significant difference that I wasn't expecting. My next project is to install a Bendix FI, which will let me improve upon that more.

I'll report more results as I do more testing.

Thanks to Michael for posting your test details and results. It was a big help in setting up my initial tables

Larry

Unless you have pictures, it doesn't exist!

Anxious to see further results.

Larry,

In using the old Slick Mag as your timing source, do you maintain the use of the Slick Mag coil as an energy source? If not, do you have a back up source of electrons, battery, 2nd alternator...

Thanks,

Chkaharyer99 said:

Larry,

In using the old Slick Mag as your timing source, do you maintain the use of the Slick Mag coil as an energy source? If not, do you have a back up source of electrons, battery, 2nd alternator...

Thanks,

Click to expand...

The old slick mag is just a carcass to house the crankshaft timing pickup. It really serves to hold the 6-1 timing wheel (round aluminum plate with 5 magnets on 60* radials) that spins on the shaft (it turns at crankshaft speed) and holds the hall sensor that senses the magnets.

The MS box controls everything (it connects to the Hall sensor in the mag) and it is connected to an external coil pack that is generating the spark. I ended up using Autolite 386 plugs (18mm) to avoid the 14-18mm adapters.

I do not have a backup power source beyond my battery. This setup doesn't draw much more than an amp and should run for quite a while on battery power. I still have the other mag, so even a catastrophic electrical failure doesn't stop my engine. While adding a second coil would be cheap and easy (MS could drive both coils) for full EI, I don't like being dependant upon the MS box or the electrical system to insure my safety. I wouldn't have "rolled my own" if I didn't have the security of the backup mag.

Larry

pics??

Any chance you could post some pictures of your pickup setup and overall installation? I'm interested to see it.

Thanks.

N363RV said:

Any chance you could post some pictures of your pickup setup and overall installation? I'm interested to see it.

Thanks.

Click to expand...

Unfortunately I didn't snap any pictures of it when I put it together. You are welcome to call me and I can walk you through how I built it. I made a plate to attach where the points used to be (used the two screws from the points install) and installed a hall sensor in it. I epoxied it into place so that it is secure and protected from elements. I then made a round disk out of 1/8" 2024. I added a small piece of 1/4" 2024 to the center to add set screws (this allows vertical setting for the gap). I then made 6 radial lines from the center (60* spacing) and drilled and installed 5 magnets.

You can spin up the mag on the bench with a 1/2" drill for testing.

It has run without issue for about 70 hours now. Time will tell on long-term reliability.

PM me your number and I can call you to walk through the details if interested.

Larry

Are you using the Tunerstudio software?

darata said:

Are you using the Tunerstudio software?

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I am, although I don't use it in the air. I used it for the initial setup and to modify the ignition map. At some point I will bring the laptop on the plane and make real-time adjustments to timing.

Larry

Very neat! I had the system installed on my racecar and it was very intuitive. Being able to have the system auto tune the fuel map in real time based on a wide band O2 sensor was very helpful. I never thought of it being used in aircraft. Looking forward to reading about your experiences.

Fuel Injection Mega Squirt???

Any consideration on using electronic fuel injection with the "Mega Squirt" system? I see SDS has focused their product line squarely at aviation applications which seems to be like the Mega Squirt system. How difficult is assembly of Mega Squirt board? Are you using mag on 2nd pad for redundant backup?

mmcdonald said:

Any consideration on using electronic fuel injection with the "Mega Squirt" system? I see SDS has focused their product line squarely at aviation applications which seems to be like the Mega Squirt system. How difficult is assembly of Mega Squirt board? Are you using mag on 2nd pad for redundant backup?

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You can get preassembled MegaSquirt boards from 3rd parties. I can get info from my friend on who he used. He is pretty happy with their work. PM me if you'd like me to do that.

mmcdonald said:

Any consideration on using electronic fuel injection with the "Mega Squirt" system? I see SDS has focused their product line squarely at aviation applications which seems to be like the Mega Squirt system. How difficult is assembly of Mega Squirt board? Are you using mag on 2nd pad for redundant backup?

Click to expand...

Yes, I have the MS controlling one set of plugs and an impulse mag for the other set. I don't feel I am giving up that much performance and feel safer that way. Though I may build a second MS to replace the other mag some day. I don't feel the MS has any greater failure risk than the Mag; I just want redundant systems. However, this step would have to involve some form of battery backup. That said, the one MS can easily control both ignitions, with the addition of another coil.

I have installed a complete MS system (fuel injection and ignition - it even controls my water/air intercooler pump) in an old Porsche that I added a Turbo to. The box is relatively easy to build (maybe 8-12 hours to build and test, if your good with a soldering iron) and you can also buy pre-made units that are quite a bit smaller (due to surface mount components). In the end, I just don't know if I had enough confidence in the system to be a true aviation EFII system. While I have had no failures in the Porsche, if they had happened it would a minor inconvenience, not an Emergency. Even with a packaged system, like SDS, I am not sure how comfortable I would be without redundancy in the electronics (dual CPU's, dual pickups, etc.). I feel safer due to the lack of electronics required to keep my prop spinning and I make my money in the technology business.

Unlike the EI that gives me improved performance and efficiency, the Electronic injection really only drives convenience, smoothness, better hot start / idle, etc. While an improvement in many areas, I don't believe it will do all that much for performance and efficiency that I couldn't otherwise get, albeit through manual effort, therefore why take the risk of introducing electronic components and there dependence on available electricity. I found the greatest advantages were in the tunability (better manage rapid MAP changes/acceleration, tightly tune RPM/MAP coordinate fuel mapping, etc. This is huge on a car, but we run our engines in varying steady states that are easy to manage with the manual mixture control, assuming you have a mechanical FI setup of course.

Larry

Larry

lr172 said:

...Unlike the EI that gives me improved performance and efficiency, the Electronic injection really only drives convenience, smoothness, better hot start / idle, etc. While an improvement in many areas, I don't believe it will do all that much for performance and efficiency that I couldn't otherwise get, albeit through manual effort, therefore why take the risk of introducing electronic components and there dependence on available electricity. I found the greatest advantages were in the tunability (better manage rapid MAP changes/acceleration, tightly tune RPM/MAP coordinate fuel mapping, etc. This is huge on a car, but we run our engines in varying steady states that are easy to manage with the manual mixture control, assuming you have a mechanical FI setup of course...

Click to expand...

I used to feel exactly the same way, but the more I've learned about EFI in general and the very specific aviation targeted advancements that Ross has created has made me take another look. Just like the leap he made with the CPI over prior ignition systems, I think these features of the SDS system are going to show performance gains well beyond the "convenience" and "gee whiz" factor of prior EFI efforts. Dave Anders results are impressive from a pure efficiency standpoint and Bill's supercharged Rocket certainly is compelling. Though I have no firsthand performance data yet, its coming. When my Rocket flies again it will be with the full SDS system. And unlike the race prepped or highly optimized examples above, my bone stock engine and "average" airframe build should show what this system has to offer to "everyman".

So while I can't argue against your above quote with conviction just yet, this serves as fair warning that I should be better prepared around the first of the year.

slngsht said:

You can get preassembled MegaSquirt boards from 3rd parties. I can get info from my friend on who he used. He is pretty happy with their work. PM me if you'd like me to do that.

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And remember, if the intent is stand-alone ignition (no fuel injection), the Megasquirt spin-off is the Megajolt ignition controller. It handles RPM/MP advance calculations for a Ford EDIS system, which is stand-alone at 10 BTDC without it.

The assembled controller is a whopping $169:

https://www.autosportlabs.com/product-category/megajolt-ignition/



Lots of ways to trigger it. The EDIS just needs a waveform with 35 cycles and a skip:



I've been flying one of these about 10 months now. The other one is going on at the next annual. 36 tooth gear with one tooth removed, and a Nippondesno reluctor, in aluminum magneto-hole bodies:

Toobuilder said:

I used to feel exactly the same way, but the more I've learned about EFI in general and the very specific aviation targeted advancements that Ross has created has made me take another look. Just like the leap he made with the CPI over prior ignition systems, I think these features of the SDS system are going to show performance gains well beyond the "convenience" and "gee whiz" factor of prior EFI efforts. Dave Anders results are impressive from a pure efficiency standpoint and Bill's supercharged Rocket certainly is compelling. Though I have no firsthand performance data yet, its coming. When my Rocket flies again it will be with the full SDS system. And unlike the race prepped or highly optimized examples above, my bone stock engine and "average" airframe build should show what this system has to offer to "everyman".

So while I can't argue against your above quote with conviction just yet, this serves as fair warning that I should be better prepared around the first of the year.

Click to expand...

I certainly see the theoretical advantages (tighter pulse/flow control, improved combustion due to better atomization, etc.) to it, no doubt at all. I am anxious to see the results of your efforts here. You have solid testing methodologies and I am sure you will put it through it's paces. I stand ready to be converted

Larry

DanH said:

And remember, if the intent is stand-alone ignition (no fuel injection), the Megasquirt spin-off is the Megajolt ignition controller. It handles RPM/MP advance calculations for a Ford EDIS system, which is stand-alone at 10 BTDC without it.

The assembled controller is a whopping $169:

https://www.autosportlabs.com/product-category/megajolt-ignition/



Lots of ways to trigger it. The EDIS just needs a waveform with 35 cycles and a skip:



I've been flying one of these about 10 months now. The other one is going on at the next annual. 36 tooth gear with one tooth removed, and a Nippondesno reluctor, in aluminum magneto-hole bodies:

Click to expand...

I am still anxiously awaiting your announcement to offer and sell those pickup units. They are very impressive. I wish that I had the skills and equipment to make them.

Larry

Dan,

That looks awesome.

Seems to me your design fills a market gap that is not currently available.

The advantage to me seems to be that you've taken away the vulnerability of the pickup on the flywheel.

If it had the added capability of generating its own electrons like a magneto it looks like it would be a bolt on replacement for mags.

Thanks for sharing.

In a quest for 'excess redundancy' I have wondered about a mechanical backup for electronic fuel injection?
I recall one builder used a Marvel Carb for the throttle body, with the fuel turned off. If the injection computer conked, he could turn on low pressure fuel to the carb and continue to fly. One electronic ignition, one mag, one fuel injection system one carb. Even a total electrical system failure won't stop this plane.
I was thinking of something simpler, like a fuel spray bar in the intake, and a manual control valve in the cockpit. If the computer failed, presuming at least one ignition device would still work, so open the fuel valve and adjust it until the engine runs at the throttle setting you have. Super simple...not very flexible operationally tho-
I can't be the only person thinking of this.

lr172 said:

I am still anxiously awaiting your announcement to offer and sell those pickup units.

Click to expand...

It ain't gonna happen. This is an easy builder project, but you do need access to a lathe. If you want to buy something, buy a CPI from Ross.

Chkaharyer99 said:

Seems to me your design fills a market gap that is not currently available. The advantage to me seems to be that you've taken away the vulnerability of the pickup on the flywheel.

Click to expand...

Not a new idea. Conceptually the same as an Electroair.

If it had the added capability of generating its own electrons like a magneto it looks like it would be a bolt on replacement for mags.

Click to expand...

Self generation is not really necessary, and it adds complexity, both in support wiring and internal component count. Complete independence for the duration of any flight requires a 3lb battery, one switch, and one diode... simple, reliable, and less than $50.

Mega Squirt Ignition Component Break Out

Larry & Dan thanks for posting information on your projects, I have read through it many times. Larry, could the Ignition IC components and micro-controller on the Mega Squirt board be separated out and build the board without EFI components?

mmcdonald said:

Larry & Dan thanks for posting information on your projects, I have read through it many times. Larry, could the Ignition IC components and micro-controller on the Mega Squirt board be separated out and build the board without EFI components?

Click to expand...

You mean a MegaJolt? Nah; then you wouldn't get to build it.
;-)

mmcdonald said:

Larry & Dan thanks for posting information on your projects, I have read through it many times. Larry, could the Ignition IC components and micro-controller on the Mega Squirt board be separated out and build the board without EFI components?

Click to expand...

You could leave out the components for the fuel injection, but you won't save much. They are mostly resistors, capacitors and low cost transistors. Buying the bundled kit is a bit cheaper than ordering off the BOM from digikey, as they are buying the components in larger quantities. Therefore, with the missing components, you might come up at a slightly lower cost. You certainly could leave them out and save some assembly time. I think the kit was only $220.

The CPU board is common for all control, so no savings there.

If you like buiding, it is a fun project and I would encourage you to do it. It also offers more options. It can used the EDIS components that Dan used, but many other options are available. The flipside to this flexibility is time in the learning curve. The MJ / EDIS is very straight forward. THe MS will require more education, thought and planning. Be sure to factor that into your decision. One example is that I use two different ignition tables that are activated by an external switch. I have one optimized for best power and one for 35* LOP. Another example is VR pickups vs hall effect. I had big noise issues on the VR setup in my Porsche and wanted to avoid it. I used a hall effect sensor and magnets as it is a digital, not analog signal. MS supports both.

Larry