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SDS CPI2

The LOP button is designed to be used when you lean the engine to LOP. This advances the timing (usually 3-5 degrees) and picks up some of the power lost when running lean of peak due to the slower burn rate of the mixture.

Usually see 3-6 knots come back over fixed mag timing, depending on airframe and how far LOP you are.

The amount of advance for LOP is user programmable as are the basic RPM and MAP timing curves. In fact, almost every parameter right down to cranking retard and coil charge times can be changed.

This is the "Last Word" in aircraft EI systems where you want full control of your timing and not a canned curve like most other EIs offer.
 
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If I installed this on my airplane, when I press the LOP button, what will I see?

Lets say I have a 180 hp Lycoming IO-360 with Bendix RSA fuel injection. The injectors are balanced, and I install your CPI-2 product to replace both Mags. Cruising at 8000' at 60% power and have the timing set lets say to 25 BTDC. What about 10,000' or 12,000'?

I'm guessing EGT decline, CHT's rise.....will I see airspeed rise too? How much?

If you are in fact cruising at 25 degrees advance as your baseline, then activating the LOP feature will show you 5+ knots increase in speed, a 5-10 increase in CHT (which will help, because you will be too cold), and a reduction in EGT.

This assumes that you took the 10 minutes to find "your" optimized LOP value for that condition (EGT/altitude).
 
We'll have finally cleared our order backlog for CPI-2s by tomorrow so things should return to "normal" around here. This means more time to devote to the EM-6 project which has been coming along steadily but not as fast as we hoped, due to time spent on building and shipping systems. This also means I'll finally have time to get back to other development projects which have been delayed this summer.

We can deliver CPIs in one day, CPI-2s in 2 days and EM-5s in about 3-4 days with our usual backlogs. 6 cylinder versions are available now if you're tired of waiting for other brands to be supplied.

Thanks to those who've ordered CPI-2s to upgrade from CPIs- we didn't expect much of that.
 
Dual Mag Engines

We have some new parts now to be able to remove the much hated Dual Mag setups and replace with SDS EI units.

The new parts allow mounting of one of our 4 or 6 cylinder coil packs where the mag unit used to be. The 2nd coil pack could be firewall or engine mount tube mounted. This would be applicable to SDS CPI, CPI-2 or EM-5 systems.



4 cylinder



6 cylinder
 
We have 2 different clamp styles depending on stud length and thickness of cover plate flange. These are 7075-T6 and designed to be used with no gasket- RTV only.
 
RV-3B CPI-2 install

I posted a couple photos of Mike Kellems' CPI-2 install on his RV-3B. He's been running CPIs for a while now and decided he wanted the newer system on there. Not much space on these aircraft but he's getting it done.

Photos are down near the bottom of the page: http://www.sdsefi.com/cpi2.htm

Good stuff Mike and thanks for the photos as always.
 
Thanks Mike. Flickr isn't the easiest thing to figure out and you'll have to trim the link afterwards.

Click your photo on Flickr
Click curved arrow bottom right
Upper right, choose BBcode
Right click the link to copy code
Click on VAF insert photo icon
Backspace the HTTP to get rid of it
Right click in the empty box to paste your link
Delete on both ends of the code
Delete everything behind [/URL]
Delete the photo file name just in front of [/URL]
Check if it appears right in the VAF post by clicking preview before posting

BTW, limit max width to 800 pixels, crop that in a photo editor.

Clear as mud, right?
 
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CPI2 in RV3B

Hi Ross,
I couldn't figure out flickr so I went searching and found smugmug. we'll see how this goes.
I highly recommend both CPI and CPI2 to anyone looking for an electronic ignition.
I have about 5hrs on my new CPI2 and am very happy so far with the performance.
I had used the regular CPI for awhile and switched over for the panel space saved.
It incorporates all of the previous features into one small instrument. Auto backup battery switching is reassuring. Preflight checks are a breeze as well.
I am especially pleased with the fit in my RV3B panel. Sure looks good I think.
Anyone with a single place or centerline 2 place A/C will like the size and ease of inflight use.
I would be happy to field questions regarding installation and operation of this system.
Thanks to you&Barry for a great ignition system and all of your excellent customer service!
Here are a couple more photos ?. Mike



 
The LOP button is designed to be used when you lean the engine to LOP. This advances the timing (usually 3-5 degrees) and picks up some of the power lost when running lean of peak due to the slower burn rate of the mixture.

Usually see 3-6 knots come back over fixed mag timing, depending on airframe and how far LOP you are.

The amount of advance for LOP is user programmable as are the basic RPM and MAP timing curves. In fact, almost every parameter right down to cranking retard and coil charge times can be changed.

This is the "Last Word" in aircraft EI systems where you want full control of your timing and not a canned curve like most other EIs offer.

I'm not from Missouri (actually from Victoria), but all of these claims about ignition timing made me skeptical. I have an IO540 9.2:1 running one magneto and an Electroair electronic ignition.

I have a switch that cuts off the MAP sensor so I can have baseline timing or advanced timing. That also provided me a convenient spot to intercept the advance signal and massage it with an arduino controller.

So I wrote a sketch that allowed me to add or subtract ignition timing in flight and test some of the claims.

The first test was to try changing the timing with a rich 'best power' mixture at 8500 PA. Stock timing from the Electroair was 33 degrees. I tried between 27 and 38 degrees with no measureable change in airspeed of 201 knots.

The second test was to go LOP around 180 knots and find the best timing. Baseline was 177 knots at 33 degrees and 180 knots at 38 degrees. Yeah!

So, based on this rather elementary test, it looks like the 'canned' curve is a bit too conservative LOP, thus proving Ross's assertion. But I also had to watch CHTs in the climb, so maybe it was too agressive ROP. I can always turn off the advance with the switch, though.

So maybe I can change the shape of my advance curve with some simple programming... less advance when ROP and more advance when LOP. I can figure this out from the Dynon serial data stream.

Vern
 
Your test results mirror typical experience. We haven't found much difference ROP where power seems to be pretty insensitive to timing (though CHTs usually aren't).

LOP, depending on how much and MAP, typical RVs see 3-5 more knots running 32 to 35 degrees total on PV engines. Really high and LOP, some customers claim around 37ish gives best speed.

If you have a long leg, smooth air and some patience to let things stabilize, you can easily see what timing gives best TAS with the CPI/ CPI-2 under various MAP and mixture settings.

I'd be interested in people's feedback from testing.
 
Angle valve engine timing

I have been testing my angle valve engine timing as a function of mixture, RPM, and MAP for about two years. I am very close to what I consider my best curves. I say curves because the most fundamental thing I have learned is that you need a minimum of two curves, one for ROP and another for LOP. My ROP curve covers everything from starting to climb and high power cruise. My LOP curve covers only 2350 to 2700RPM and below 25MAP. Mostly I use it between 18 and 22MAP because of my typical cruise altitudes. I plan to distribute those curves to a friend with a similar engine soon. If he confirms my data we hope to distribute that data to the community.

If you use only one curve you will be too advanced for ROP or not advanced enough for LOP. Both conditions can be acceptable if you set limits on the advance curve, but it is important to understand that too much advance is merely adding heat to the combustion without increased power. A quick summary of my results would be that an angle valve engine and a parallel valve engine respond very differently to advance changes.

All my testing has been done with the SDS EM5 computer which uses the CPI/CPI-2 ignition software, but adds electronic fuel injection.
 
We welcome your input on the AV engines Marvin.

BTW, the CPI-2 manual has be updated today on the website. We also now list revisions at the bottom of the manual so you can know what was changed.
 
We've got a number of CPI-2s flying now with more coming soon. We encountered 2 installations where there seemed to be incredible amounts of electrical noise in the airplanes and this was often scrambling the data on the programmer LCD and LEDs. The engines always continued to run fine.

If anyone encounters issues with hyrogliphics or blank lines in the LCD or flashing LED indicators, drop me an email or PM and we'll get this addressed at our expense.

Despite extensive testing during development where we sat the controllers right on top of coil packs while they are firing spark plugs a foot away and wrapping the programmer cable around the spark plug wires with no issues, these 2 installations appear to have more noise present than this "worst case" testing scenario. Both of these problem cases have been rectified now with a programmer mod.
 
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Magnet Position Values

In case this was missed on our website I thought I'd post it here:

"We've eliminated the need to set Magnet Position with a timing light on Lycoming engines. For engine using the dual pickup, set A ECU Magnet Position to 97 and B to 88. For single pickup installations, set it to 92."

A few new photos of a dual RV-8 install near the bottom of the CPI-2 page uploaded today.
 
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Good Speeds on an RV-8

Kevin Taylor was kind enough to send us a number of photos of his dual CPI-2 install on his RV-8.



This is running LOP. 188 KTAS. Not too shabby on an AV 360.



Kevin also has the new 2 blade Hartzell composite prop which he attributes a number more knots to. He says he's able to hit over 190 KTAS at altitude ROP.
 
We've had a flurry of CPI-2 orders in December. Thank you to every one who has placed an order. Working to get most of these shipped before the end of the year but some of our suppliers are slow in delivering certain parts at this time, mostly due to shipping delays.

Building up several programmers now as time permits. While the basic boards are machine loaded and soldered, there is still quite a bit of hand assembly required with the LEDs, LCDs and keypads into the chassis:

 
I had a very successful test flight today after the installation of my SDS CPI-2, dual channel controller and optional backup battery.

As expected the system works as advertised and I am happy to remove my two slick mags which were almost due for a rebuild.

Big thanks to Ross and Barry at SDS for being available to answer my many questions along the way. The customer service I've received from SDS has been exceptional.

I also want to shout out to Bruce Estes who installed a dual SDS CPI-2 in his RV-6. Bruce gave me lots of guidance along the way. It was also great hearing about his experiences with the system.

Lastly, a big thank you to Lee Ulrich who has an SDS EFI in his RV-7. Lee finished the install, did some fabricating and helped with the timing.
 
Congrats Charlie and thanks to Lee (of Reno fame) and Bruce for helping out. You guys were all a pleasure to work with and were patient when we had to deliver fixes for your issues.
 
Ross,

Are we going to see a new "Design1" style head for the CPI2? The current one won't fit in my panel, but the short/wide one could be made to fit.

Thanks,
schu
 
Me 3 on a Design 1 type controller for the CPI2. But I?ve already asked Ross and been told it?s not likely to happen soon. So I?ll be fitting the current design in my Rocket.
 
The CPI-2 programmer has a LOP switch on the programmer keypad.

Some folks who want the Design1 programmer to fit their panel space have ordered a parred down EM-5 to do ignition only. This is slightly less expensive than the CPI-2 but you don't have the automatic battery switch over capability.

Unfortunately, we are so busy these days we won't have time until 2021 to look at interfacing the Design1 PGU with the CPI-2. Our priority is to finish the design and testing of the EM-6 ECU first as that is already almost 2 years behind schedule.

CPI-2s are sold out at this time, more PCBs are being produced now. Should have those in hand just before the end of this month.
 
Ross,

In comparing the CPI-2 to the other solutions, the thing that keeps coming up is the battery switch and OV protection.

I don't plan on using a backup battery because I have a secondary alternator in my design, which begs the question, how does the CPI2 deal with an OV condition when the battery is not used? Does it shut down until the voltage levels return to normal? Or does it blow it's internal fuse? What do the CPI1 and EM5 boxes do in those conditions?

Both of my alternators have OV protection, but if I reset a breaker in flight and it happens again for 100ms, I don't want it to take out my engine.
 
The CPI-2 will typically switch over to the backup battery if the primary goes OV. It will switch back if the primary voltage returns to normal.

If you don't plan a backup battery with the CPI-2, I'd say there are few advantages to using it over the CPI if you already have OV protection unless panel space is at a premium.

On the CPI and EM-5, there is no OV protection built in so you should have external OV protection.

With almost everyone fitting glass panels these days, you should have external OV protection also fitted to protect those electronics as well.
 
I appreciate the response, but it doesn't really answer my question. If I apply 40v to a CPI2 that doesn't have an external battery, what does it do? Fry? Switch off? Blow a fuse?

I do have OV protection on both alternators, but still want to know what it does.
 
I appreciate the response, but it doesn't really answer my question. If I apply 40v to a CPI2 that doesn't have an external battery, what does it do? Fry? Switch off? Blow a fuse?

I do have OV protection on both alternators, but still want to know what it does.
From the SDS CPi-2 manual:

"The CPi2 has a built in crowbar and if Mainbus voltage goes above approximately 24 volts for several milliseconds, the crowbar will short circuit and blow the 2 amp fuse on the side of the ecu disconnecting the CPi2 from your Mainbus power. Trip time varies for the crowbar depending on how high the mainbus voltage goes. Higher voltage equals quicker trip time. The crowbar has filtering to prevent triggering from short voltage spikes."
 
I appreciate the response, but it doesn't really answer my question. If I apply 40v to a CPI2 that doesn't have an external battery, what does it do? Fry? Switch off? Blow a fuse?

I do have OV protection on both alternators, but still want to know what it does.

The internal crowbar protects the ECU from primary bus OV. The CPI-2 is designed to use a backup battery for redundancy since it's an electrically dependent ignition system. Crowbar trips, saves ECU which then switches over to backup power and keeps the engine running.

As I said before, if you don't run a backup battery with the CPI-2, there are not many good reasons to choose it over a CPI.
 
Ross,

In comparing the CPI-2 to the other solutions, the thing that keeps coming up is the battery switch and OV protection.

I don't plan on using a backup battery because I have a secondary alternator in my design, which begs the question, how does the CPI2 deal with an OV condition when the battery is not used? Does it shut down until the voltage levels return to normal? Or does it blow it's internal fuse? What do the CPI1 and EM5 boxes do in those conditions?

Both of my alternators have OV protection, but if I reset a breaker in flight and it happens again for 100ms, I don't want it to take out my engine.

I have a secondary alternator as well, but I'm still using the backup battery recommended by SDS with my CPi-2 system. It weighs less than 3lbs, the CPi-2 unit takes care of the charging and switchover, and the mounting bracket and wiring provided by SDS makes installation simple.

I like the peace of mind knowing that if everything else goes wrong my ignition system can stand on its own at least long enough to get me on the ground with the fan still running. For me it's very cheap insurance.
 
The internal crowbar protects the ECU from primary bus OV. The CPI-2 is designed to use a backup battery for redundancy since it's an electrically dependent ignition system. Crowbar trips, saves ECU which then switches over to backup power and keeps the engine running.

As I said before, if you don't run a backup battery with the CPI-2, there are not many good reasons to choose it over a CPI.

Well, one reason is for starting with one ignition and upgrading to two without more holes in the panel, the display looks far nicer, and the remote mount head fits in my panel much better, but I'm still not sure what it would do when OV.

Your message says that the crowbar trips, then switches over to backup power, which would be missing, which leads me to believe it would simply power down, but the manual that sjarrell posted suggests it will blow the 2 amp fuse.

Perhaps I should be even more specific in my question.

What exactly happens when a CPI2 without a battery sees and OV? Does it power down? Power down and blow a fuse? Or something else?

As for the additional weight, I'm building as light as I reasonably can, I've already taken on the weight for backup alt to power my EFIS and boost pump, and EI, I don't want more redundant weight.
 
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Well, one reason is for starting with one ignition and upgrading to two without more holes in the panel, the display looks far nicer, and the remote mount head fits in my panel much better, but I'm still not sure what it would do when OV.

Your message says that the crowbar trips, then switches over to backup power, which would be missing, which leads me to believe it would simply power down, but the manual that sjarrell posted suggests it will blow the 2 amp fuse.

Perhaps I should be even more specific in my question.

What exactly happens when a CPI2 without a battery sees and OV? Does it power down? Power down and blow a fuse? Or something else?

As for the additional weight, I'm building as light as I reasonably can, I've already taken on the weight for backup alt to power my EFIS and boost pump, and EI, I don't want more redundant weight.

With no backup battery, the crowbar will pop the 2 amp fuse and you are without ignition.

I would wire and use the CPI-2 as it's designed. If you run a mag on one side, you don't need a backup battery. The crowbar will prevent OV damage to the board, fly back on the mag and you can fix your alternator/ regulator issue on the ground.

With a dual CPI-2, I wouldn't be flying without an isolated backup power source as if that fails, you're a glider.

If you have a glass panel, I'd advise a crowbar setup on the alternator and of course backup power isolated from the main battery and alternator.
 
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With no backup battery, the crowbar will pop the 2 amp fuse and you are without ignition.

I would wire and use the CPI-2 as it's designed. If you run a mag on one side, you don't need a backup battery. The crowbar will prevent OV damage to the board, fly back on the mag and you can fix your alternator/ regulator issue on the ground.

With a dual CPI-2, I wouldn't be flying without an isolated backup power source as if that fails, you're a glider.

If you have a glass panel, I'd advise a crowbar setup on the alternator and of course backup power isolated from the main battery and alternator.

Thanks for answering.

I do have a glass panel, and I have an external crowbar setup on my BandC 8 amp alternator, as well as internal crowbar on my plane power alternator.

The rub is that not all of these electronics conform to a standard, so the question is which OV crowbar circuit is faster, or rather trips at a lower voltage.

It looks like the CPI-2 doesn't protect itself until 24 volts, so as long as my plane power alternator trips before then, I shouldn't have any issues.

Can you tell me what voltage a CPI-1 will tolerate before it fries? Also 24 volts?
 
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Another reason to use CPI2:

In another thread, Ross writes

We get the question about using the old mag switches for the CPI fairly often. Since they ground to disable, that's opposite to what is needed here. It's easier to replace with toggles although you may have to make a nice cover plate to hide the big hole.

While with the cpi-2, in the manual you get a comment about yellow and grey wires, that when grounded, cause the coil to drop out.

So, if you want to you a traditional aircraft mag switch, the CPI-2 is the better solution.

All that said, couldn't I just get a relay and wire it to the cpi1 to provide power in a normally closed way, then with the mag check, open the relay, which drops the cpi1? On one hand I hate having a relay between the CPI and battery, on the other hand, it shouldn't fail if it's wired normally closed and only opened to do a mag check.
 
Thanks for answering.

I do have a glass panel, and I have an external crowbar setup on my BandC 8 amp alternator, as well as internal crowbar on my plane power alternator.

The rub is that not all of these electronics conform to a standard, so the question is which OV crowbar circuit is faster, or rather trips at a lower voltage.

It looks like the CPI-2 doesn't protect itself until 24 volts, so as long as my plane power alternator trips before then, I shouldn't have any issues.

Can you tell me what voltage a CPI-1 will tolerate before it fries? Also 24 volts?

The CPI-2 will switch over to the backup battery at 16.5V so it's isolated when that happens and that's super quick, like micro seconds. The crowbar acts in milliseconds to save the PCB and that time is dependent on the degree of OV, in testing, typically 24-30V.

I don't have any knowledge of other brands of devices which is the main reason we did our own protection on the CPI-2. It protects itself and keeps the engine running. That's our main concern.

If you have OV protection on the alternator, OV protection on the CPI-2 main power input and the auto switchover to an isolated backup battery, you have 3 layers of protection.
 
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The plane power people say their OV protection kicks in at 17.4v.

Given that the CPI-2 does it at 24-30V, the alternator should kick it self out and the buss return back to battery voltage long before the CPI-2 gets forceful with it's fuse.

That's when I notice that my alternator isn't working because buss voltage drops below 13V, then flip my alternate alternator switch and press on.

I think I'll do CPI-2 without battery backup as it seems the OV will trip in the order I want it to, and I have a second source of power (battery) and a 3rd source of power (aux alt). I don't think I need to give up the weight for a 4th source of power.

Can you comment on cpi1 max voltage? Or using a relay with a CPI to retain the mag switch?

Thanks for being available to answer questions, I feel like I fully understand what I'm getting into now, and can make the best decision.

schu
 
Schu,
I recently went through the whole decision process of dual EI, single EI/mag, CPI/CPI2, EM5. Part of this process was getting comfortable with the concept of dual EI and the resulting electrically dependent engine. Once I decided I could be comfortable with the dual set up I started researching all of the available options. The more I researched the more I became comfortable with letting the CPI2 do it?s thing if something happened to the main power feed. What Ross and Barry have done is create a system that can be easily integrated into an airplane with a basic electrical system, take care of itself, and keep the big cooling fan spinning with as little pilot action as possible. A backup battery is an integral part of the system and should not be left out. The safest route is to use a product as it was designed to be used. If you are not comfortable with this then IMO you should take Ross?s advise and not use the CPI2. A pair of CPI?s or an ignition only EM5 will let you do your own thing with regards to redundancy. I considered this, I even had Ross send me the hardware for each of them so I could do the touchy-feely thing and figure out how to best integrate each into my airplane. In the end the CPI2 won out.
 
The plane power people say their OV protection kicks in at 17.4v.

Given that the CPI-2 does it at 24-30V, the alternator should kick it self out and the buss return back to battery voltage long before the CPI-2 gets forceful with it's fuse.

That's when I notice that my alternator isn't working because buss voltage drops below 13V, then flip my alternate alternator switch and press on.

I think I'll do CPI-2 without battery backup as it seems the OV will trip in the order I want it to, and I have a second source of power (battery) and a 3rd source of power (aux alt). I don't think I need to give up the weight for a 4th source of power.

Can you comment on cpi1 max voltage? Or using a relay with a CPI to retain the mag switch?

Thanks for being available to answer questions, I feel like I fully understand what I'm getting into now, and can make the best decision.

schu

The CPI has been tested to 20V. It may go higher but I suspect the 5V regulator inside would get pretty hot eventually.

We have a schematic to use the standard mag switch to power the CPI on/off.

I recommend you have that alternator crowbar if you have critical electronics on board.

If you have a dual CPI-2, I'd recommend a backup battery as that's what the system was designed around for redundancy. There is a lot going on behind the scenes in software and hardware on the CPI-2 to have seamless switch over and isolation in case of primary OV. Best to use it as designed rather than coming up with untested alternate power solutions.

We are so busy now with orders, support and other development that we are short on time to investigate alternate power possibilities. We like to stick with what we have tested and what has proven reliable in the field on hundreds of flying aircraft. Sorry I've been slow to respond over the last couple days, 50+ emails and 40+ phone calls per day has kinda swamped us and created a big order backlog which we need to start wading through to get back on track.

Thanks to everyone for their interest and support of SDS products!
 
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Schu,
..... What Ross and Barry have done is create a system that can be easily integrated into an airplane with a basic electrical system, take care of itself, and keep the big cooling fan spinning with as little pilot action as possible. A backup battery is an integral part of the system and should not be left out. The safest route is to use a product as it was designed to be used. If you are not comfortable with this then IMO you should take Ross?s advise and not use the CPI2.....

Well put. I agree completely.
 
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