EFII - the jury is coming in

[rv6ejguy]

Originally Posted by rmartingt

Is there any confirmation on this? That is, if my RPM fuel value is 165 at 2250 and 170 at 2500, what is the value for 2375? Is it, 165, 170 or 167.5?



So let's say I want to run LOP at 24"/2400 and below, best power above that, running mogas, C/S prop, and I have an AFR meter. How would I do that? I guess detailed tuning would have to happen in flight to make sure temperatures don't hit limits. I guess the timing map helps alleviate some of the concerns?

I've been puzzling over this for a couple days now, and reading all kinds of articles on engine operation. I'm just not really familiar with the details of piston engine operation and theory beyond the absolute basics. Props were only briefly mentioned in school, and when they were they were always turbine-powered; the only engines I ever messed with were .40-class and .049 2-cycle RC ones.

The break points in software for RPM Fuel happen 125rpm before and 125 rpm after the displayed rpm. This is to be sure you are programming the spot displayed on the screen. So 2500 is covered from 2375 to 2625. You should always look at the programmer when programming, not other tach displays. There is no interpolation between rpm break points.

There are 64 MAP points. Using a 1 Bar MAP sensor for naturally aspirated engines gives you about 0.5 inch increments. There is MAP averaging to calm down any scatter.

There are enough small variables that LOP operation should probably be set via the mixture control using either EGT or the wideband. You could cross the rpm and MAP points under other conditions where you might not want to be LOP.

Injectors are batch fired, usually in pairs depending on the system. They are not timed to valve events with this system. OTS injectors are usually flow matched to about 2-3% variance. Along with this, each port flows slightly different amounts of air so this results in the same issues as with mechanical injectors hence the GAMI idea is needed to correct AFRs for individual cylinder.

Some very high end EFI systems allow you to individually trim each injector pulse but they are very expensive and you can imagine how long this might take to program.

[clam]

... I don't have anything to add to the discussion at this point, but rather throwing my name in with EFII crowd. What I have installed to date:

-RV-8, Titan IOX-360, horizontal induction
-EFII dual electronic ignitions, dual ECU installed
-EFII bus manager installed
-EFII electric fuel pump and traditional engine driven mechanical fuel pump
-my fuel pump system is NOT EFII electronically controlled system
-single alternator, dual PC680 battery
-Silverhawk EXP injector servo

I have above installed, but no where near engine start. I will add this one point... if you are contemplating this system and using EFII bus manager, plan electrical system early. I had electrical mostly complete before I made the decision to instal the bus manager. The bus manager looks like a great piece of gear and would have simplified installation had I started with it initially.

[Jesse]

Chris Golden has the plane now and will be working through all of the fine tuning of the ECU's.

Noted thus far is that the GAMI spread is about 1.4gph, so hopefully he can get those things worked out.

Robert said there is interpolation between rpm settings, but in our testing there was none, which agrees with what rv6ejguy said.

It is a smooth running engine, but it will be even better if we can get that GAMi spread tightened up.

[carrollcw]

I recently finished my Phase 1 in an RV7 running dual EFII injection and ignition on a Titan IOX-370. A couple of points:

Do not think that the engine will run anywhere NEAR its capabilities with the stock EFII setup. Unfortunately, you will have to do numerous engine runs before the first flight getting it in the ball park. This stinks for a new engine, but at least the Titan has a 3 hour dyno run at the factory, so much of the break in is completed there.

You have to program each ECU individually. In order to do this, you have to unplug the programmer from one ECU and into the other. This is a bit of a pain.

At some point you will have to start tweaking the programming in flight to get it so the fuel mixture knob is basically hands off in flight pointed at the 12 oclock position keeping all the temps in tolerance. If you have an O2 sensor, this is much easier. Once adjusted properly, you should only have to touch it to run LOP. Adjust your ECU 88 in flight (it is the one that should be controlling the fuel injection curve), land, write down the new settings, then plug in the programmer to 71 and make it match the 88 numbers.

There is NO information on Robert's website on how to adjust all this stuff. However, his system comes from http://www.sdsefi.com/ (Simple Digital Systems EFI). Go to their website for a TON of info on what all the settings do.

Strangely enough, my engine also starts easier while hot than cold. It also runs smoother than any other aircraft engine I have heard, and idles really low. My engine sounds like a car!

My GAMI spread at higher power settings (75%) is 1 gal, however if I go LOP at lower power settings (50%) I am at .3 gal. In trying to decrease my GAMI spread at high power settings, I swapped around injectors to see if that would change the cylinders that peaked first/last and it did not do anything. Thus, all my injectors are flowing the same. There is no way to adjust that save making your own circuit for each injector to try to adjust the dwell time. My understanding is Robert does not have different sized injectors available. However, maybe they are available somewhere. Haven't looked into it yet.

I get anywhere between 4-8 GPH fuel burn when running LOP based on my MP. I am at 16.5 GPH WOT ROP. Also, when running LOP, my last cylinder to peak is usually about 90-120 deg LOP and the first will be close to 200 deg LOP. Still runs great! It takes a lot of leaning to get it to run rough.

The return line is not that big a deal. I added an AN6 firewall fitting to the fuel tank access plate right next to the supply line. However, don't forget, you have to buy the Andair valve which is expensive! About $500.

The biggest thing I hope people understand, is this IS NOT a plug and play system. You will have to do a lot of tweaking! However, once done, there is not a better system on the market!

Feel free to PM me with questions.

[rwtalbot]

Thanks for the real world reviews guys. This system has been given a fair bit of press in recent times and promoted by a few engine builders, particularly Titan Engines. The tuning you describe is nothing like some of the other FADEC products (Aerosance comes to mind).

[jetmech]

EFII MAP and tuning :
Aloha all, FWIW I?ve got over 185+ hours on the full dual efii system fuel/ign on my -7 IO360 Mattituck
Jesse did a good job on relaying his experience with the EFII.
I?ve got to agree you?ll need to do some work to get the fuel map right on out of the box. If you read and follow these instructions from the SDS site you can map it quickly: http://www.sdsefi.com/EM5%20MANUAL.pdf page 21- the wide band O2 data (AFR) logging is a good way to get the most out of the system, very easy way to fine tune the AFR quickly. I?ll do the ground runs and try and set the fuel RPM #?s to give me 12.0 (make sure engine temp is warmed up prior to making adjustments as you don?t want the START or Engine TEMP tables to be in play) then fly the plane and see what the data log has in it at the different fuel rpm?s. You?ll need to make a fuel RPM sheet to write down what you have current and what you add or subtract from the Fuel RPM # that you want to change. I use the mixture knob to add or subtract fuel % real quick and write that change % down on the fuel rpm # I?m adjusting (you can see the % change on the programmer Gauge2 _knob) don?t forget the re zero the mixture knob before you go on to the next fuel rpm # or you?ll skew all the fuel rpm numbers that % of change. Once you have the map built you don?t have to play with the mixture knob at all.
You can use the Mixture knob to run LOP or ROP to you want to play with it in flight.
Just remember to add it to the Takeoff and landing checklist to make sure its centered up
My 2cents
Lee

[rv6ejguy]

Originally Posted by rwtalbot

Thanks for the real world reviews guys. This system has been given a fair bit of press in recent times and promoted by a few engine builders, particularly Titan Engines. The tuning you describe is nothing like some of the other FADEC products (Aerosance comes to mind).

This is a user programmable system so it's not like an OEM engineered and programmed system like Powerlink or IE2 which is fitted and programmed to specific engines. It's also different from aftermarket aviation solutions like the Eagle EMS which is around $11K.

The idea is to give users in Experimental Aviation many of the benefits offered by expensive, factory developed FADECs at a fraction of the price. One of the challenges in programming for a wide variety of experimental engines is the variety of displacements, induction, porting , cam and exhaust system differences. The OEM systems only have to work on one engine configuration and their engineers can spend many hours mapping to that end.

This article may be helpful for some people to better understand the system: http://www.sdsefi.com/aircrafttuninglyc.htm

Information sharing and feedback from users is helping to shape future improvements and developments and hopefully improve initial setups for different engine configurations.

Also, just coming available now is 8 channel data logging to PC capability to further assist in mapping the system.

[rcpaisley]

Here are some general notes just to clarify some of the things discussed:

1. The beauty of electronic fuel injection is that you get the same fuel to all cylinders (balanced delivery) under all operating conditions from starting to full power. This is not possible with any other type of fuel delivery. The benefits of this are very noticeable when operating your engine. You also have a very easy way to tune the fuel delivery at different operating points - also a huge benefit.

2. GAMI spreads are a method to attempt to balance mechanical fuel injection systems. This technique does not take into account that fact that you may have (probably do have) imbalanced air flow to the cylinders as well. GAMI spread information is not applicable to electronic injection - you already have balanced fuel delivery. The GAMI spread that is witnessed with electronic injection is not an indication of unbalanced fuel delivery, it is an indication of the air delivery imbalance. I have had customers suggest that they want to unbalance the injector flow to lessen the GAMI spread - don't do this. This is working against tuning balance. Fixing the air flow imbalance has no simple solution. Unless you are going to engage in an engine designing exercise, you are stuck with the air flow balance or imbalance that you have.
The best that can be done is to have balanced fuel delivery and a high energy ignition to ensure complete combustion even if there is an air/fuel ratio variance between cylinders. This is exactly what the EFII system does.
This will give you the best power balance between cylinders and the smoothest, most efficient engine.

3. EFII tuning. There are only five numbers to tune to dial in the fuel delivery of your engine when it is making cruise to high power levels. This can be done in a few minutes with minimal experience with the EFII system.
Simply use the tuning knob to find out what percentage change you need to the fuel delivery to get an air/fuel ratio of 13:1, change the fuel delivery number by that percentage and you have it. This is done in 250 rpm increments. The ECU will handle figuring out the delivery between those data points. We try to go over all the ECU values with each customer before they tune their engine so that they know where the numbers are, and how to change them. Once you do this once, the mystery rapidly fades away.

4. Flying. Once you have a basic tune up, you don't have to touch anything to fly. The ECU will handle the entire fuel delivery task. After you have a little familiarity with the system, you can reduce the fuel numbers at cruise rpms to automatically lean. You can also go a little bit richer (12.5:1) at max power rpms.

Yes, there are some new things to become familiar with. Yes, there are some big advantages to having the ability to tune your engine from the cockpit.

We have customers from a wide variety of educational backgrounds with a wide variety of mechanical skills. I am always amazed at how well the vast majority of customers get up to speed quickly and painlessly. It is great to see them get to enjoy all the advantages of their "modern" aircraft engine.

Robert

[carrollcw]

Of course Robert is right on point. Just to clarify though, in order to get your air/fuel ratio data, you must have an oxygen sensor installed. The EFII manual recommends it, but if you are going to have any chance of getting this programmed correctly, you MUST have an O2 sensor.

Now, I do not have an O2 sensor installed, YET! Luckily, I have a neighbor that has been running a similar engine with the EFII for years. Thus, I was able to take his programming and enter it into mine. Without his help, there was no way I could have gotten it running smoothly. My next aircraft parts purchase is going to be an O2 sensor so I can fine tune my system.

So, the bottom line, if you're gonna install EFII, also plan on putting in an O2 sensor.

Again, I am a firm believer, there is not a better injection and ignition system on the market today. You must understand however, this is not a plug and play system!

[carrollcw]

BTW, Robert at EFII has been a ton of help. Great customer service! Thanks!

A small recommendation though, you have a lot of accessory parts available that are not listed on your website, such as the fuel flow box and throttle body adapter. It would be helpful if you listed all the accessories on your site. Also, a programming manual would be useful.