SDS EFI in 2020

[airguy]

Originally Posted by Ralph Inkster

Greg,
I'm using the delay relay you suggested for the Bellenger power.

PM sent.

I've had zero trouble with the delay relay on mine, it seems to be a good reliable unit.

[David Carter]

Originally Posted by Ralph Inkster

To make the Ballinger display on the SDS control head, it had to be set to the 'Extreme range (gas)', the SDS O2 sensor input has to be set to 'AEM (new)' format. AFR display values on both units are not exactly same but within a couple tenths of each other, example 15.2 on Ballenger vs 15.3 showing on the SDS.

Ralph - I'm not quite understanding the reason for the Extreme range vs. the Standard range. Is the Extreme range needed because you expect to operate outside the 9 to 16 AFR range provided by the Standard setting? My understanding is that 9 is way too rich. With 16 AFR being around 50F LoP, I could understand possibly wanting more range on the lean end.

Extreme gives you a 14-point AFR range vs. 7 points for Standard, but at the cost of sensitivity. A 1.0v change in the A/D output from the Ballenger is 1.4 AFR in Standard or 2.8 AFR in Extreme.

I'm building an Arduino-based closed-loop mixture controller using the Ballenger box & a linear servo to push-pull the mixture knob. I'm trying to decide how many presets I need, two or three. RoP, LoP, and maybe Takeoff. Thus my question about AFR values during takeoff. It sounds like a small detail, but the answer changes the switchology required, and thus my panel layout.

Thanks!
David

[Ralph Inkster]

Good luck with your Adrino system, sounds interesting, sounds like a lot of work!

The reason for me using the extreme scale was to adapt the Ballenger output to read on my SDS panel control head. It also came in handy during testing & setup as I did explore leaning values higher than those I decided to be safe and workable for me.
In my case, displaying the AFR is 'displaying the result' of the SDS EI/EFI tuning. It is not used as a controlling factor in the running of the engine as in 'closed loop' systems. The SDS (Aviation) system use OAT/TPS/RPM/MAP/CHT data to run the engine.
Ross has a chart on his website that shows general AFR ratios to power output that might help you, but AFR is only part of the operating story.

[rv6ejguy]

We'll be implementing a 3% price increase effective Jan. 1/21 to cover an increase in aluminum billet and other parts prices we've had from vendors over the last year plus we've been supplying a few extra bits in the kits which we hadn't been charging for.

For early 2021, we'll be coming out with some new parts to make installation easier for vertical induction engines.

Our system time to build is sitting at about 2 weeks right now on EM-5 systems, about 7 days on CPI-2 and 4 days on CPI.

[rv6ejguy]

We'll be closed Dec. 24-27. Open 28-30. Closed 31st for inventory.

Closed Jan. 1-3 and ready to roll again Jan. 4.

We have an order backlog stretching into the first week in January plus many of our suppliers aren't open much during the next 10 days either.

Thank you to all our customers who've chosen SDS products. We really appreciate your support. Thank you also for your feedback to improve our offerings. There will be more new stuff coming down the pipeline in 2021.

Happy holidays and may the best of health be with you.

Be sure to get flying if you can- that is our temporary escape from the worldly problems and stress we face on the ground these days.

[rvmills]

David and Ralph,

Here's another few data points on STD vs Ext range on the Ballenger:

I started using the AFR400V1 when it was the only choice. I found that when leaning on X-Cs, I could lean past where the AFR held at 16.0. I conducted a lot of tests to balance my injectors, for which the STD is fine...peak is in that 14.7-15.0 range, and I was fine tuning the injectors with EGT and FF, not with AFR. But these tests were a pretty solid validation that the AFR works well...peak was very close to book stoichiometric values. I also tested well into the LOP range, to see when speed fell off, and when the cylinders began to run a bit rough. Again, the primary references were EGT and FF, and with the AFR400V1, the readout was a solid 16.0 for several turns of the mixture, so it was no longer providing any additional test detail or data.

When the V2 came out, I bought it, and moved the V1 to a racing Glasair, replacing a failed system in that plane (different mfgr). Noting that the V2 does have lower sensitivity in Ext mode, I wondered if the reading would jump around more in that mode. After many tests...its hard to say...maybe a bit. But I am now able to read AFRs above 16.0 as I lean, and with balanced injectors, have leaned into the 17s and 18s before rough running occurs. Speed does drop off significantly there too.

I typically run in the high 15s (15.5 to touching 16 occasionally), which is usually a bit less than 50 LOP. Good power and speed, cool CHTs, lower FF than ROP, for sure. After all this testing, given where I run, the STD mode would likely be sufficient. However, if you want to explore the fringes of LOP and see where AFR is, the EXT mode is pretty effective.

Ralph, have you noted more jumping in the numbers in EXT mode?

David, good luck with your closed loop mixture controller. It will be interesting to see the results. Will it use AFR to set the mixture? If so, you may need to dampen the slightly fluctuating readouts. As for Takeoff AFRs, during Reno Racing, Andy (SDS user and our current Sport champ) and I discussed takeoff AFR. I had my AFR 400 V1 on a TIO-580 with 2 mags, standard FI and mixture control, and an automatic waste gate. We both used an AFR of about 10 to provide plenty of cooling. Neither of us was running anything close to full throttle on takeoff or climb, to keep temps low till we were in the chute and racing. In my RV (IO-540, standard FI, 1 mag, 1 EI), full rich sea level takeoffs are in the 10s, and up in Reno, I'll lean to high 9s low 10s. I've seen 8s if I had the mixture in too far, and then corrected. Ran fine, but its not a very efficient place to run.

Hope those numbers give you some data to work with. With that closed loop system, are you trying to replicate the magic that Ross has in his SDS? I'm sure you've thought of this, but be careful how lean you allow the linear actuator to pull the mixture at high power. Cool project tho.

Someday Ralph and Bill are gonna make me a Ross SDS guy too...just a few projects in the mill ahead of that!

Cheers,
Bob

Originally Posted by David Carter

Ralph - I'm not quite understanding the reason for the Extreme range vs. the Standard range. Is the Extreme range needed because you expect to operate outside the 9 to 16 AFR range provided by the Standard setting? My understanding is that 9 is way too rich. With 16 AFR being around 50F LoP, I could understand possibly wanting more range on the lean end.

Extreme gives you a 14-point AFR range vs. 7 points for Standard, but at the cost of sensitivity. A 1.0v change in the A/D output from the Ballenger is 1.4 AFR in Standard or 2.8 AFR in Extreme.

I'm building an Arduino-based closed-loop mixture controller using the Ballenger box & a linear servo to push-pull the mixture knob. I'm trying to decide how many presets I need, two or three. RoP, LoP, and maybe Takeoff. Thus my question about AFR values during takeoff. It sounds like a small detail, but the answer changes the switchology required, and thus my panel layout.

Thanks!
David

Originally Posted by Ralph Inkster

Good luck with your Adrino system, sounds interesting, sounds like a lot of work!

The reason for me using the extreme scale was to adapt the Ballenger output to read on my SDS panel control head. It also came in handy during testing & setup as I did explore leaning values higher than those I decided to be safe and workable for me.
In my case, displaying the AFR is 'displaying the result' of the SDS EI/EFI tuning. It is not used as a controlling factor in the running of the engine as in 'closed loop' systems. The SDS (Aviation) system use OAT/TPS/RPM/MAP/CHT data to run the engine.
Ross has a chart on his website that shows general AFR ratios to power output that might help you, but AFR is only part of the operating story.

[Ralph Inkster]

Hey Bob!
You developed a Texas twang yet?

I was getting an AFR jumping reading in both normal & ext modes with the Ballenger & AEM systems but found out was being caused by a flaky OAT temp sensor wiring connector that was causing havok with the RPM/Fuel map. Generally I sense that as the old Bosch 4.9 sensor in the AEM system was giving me leaner readings than the new Ballenger setup is now reporting, basically fooling myself that I was running leaner than I actually was. Maybe I can stretch my LOP settings further towards the 17 to 18 AFR ranges in the future, I've been settling for the 16+ range for now.
Nice thing about my current settings is that I can instantly loose a gallon per hour now without notable drop in power & NO temp changes!
Life is good, kinda.

Seasons Greatings to your bunch!

[rvmills]

Ralph,

My AFR bounces around in a manner very similar to what I saw in your video with Ross. I basically mentally average out the numbers to estimate what the AFR is. Seems plenty good for normal ops, and I still stay well rich of peak for racing. In Reno, my CHTs will start to get hot if I run leaner than about 11. By hot, I mean over 400-405...so "conservative hot", in racing terms. Hoping the new AFP servo will let us run closer to best power (12.5). Might add water on the cylinders too, to see if we can lean to a bit more power.

It would be great if we could dial in a steady AFR with the Ballenger (or any other), but I wonder if a single sensor in the left pipe can do that...I figure its getting exhaust from 2, 4 and 6, and the exhaust AFR might actually fluctuate a bit given that. With balanced injectors, they should be pretty close to each other in terms of AFR, but each is a different distance from the sensor. Of course, the exhaust pulses are extremely fast, so I'm just not sure. Ross, perhaps you may have some thoughts on that.

I'm with you on the benefits. For me, ROP to LOP leaning (say best power to hi 15s) drops FF about 2 gph, with little change in speed. Going into the 16s and 17s results in a speed loss, and into the 17s to 18s into very low CHTs (sometimes <300), an audible roughness in the motor, and a pretty marked decrease in speed. After that it gets pretty quiet

Merry Christmas Amigo, and tell that Great Scot howdy for me. I may have said Y'all once or twice, but fixin' hasn't crept in yet...well, except when I'm fixin' the plane!

Cheers,
Bob

[rv6ejguy]

Happy New Years to everyone and thank you for your support in 2020.

We are booked up through to the 3rd week in Jan. now so please be patient if you've recently ordered.

Closed on the 31st for inventory, back to it on Jan. 4.

[AdamB]

Originally Posted by rv6ejguy

Happy New Years to everyone and thank you for your support in 2020.

We are booked up through to the 3rd week in Jan. now so please be patient if you've recently ordered.

Closed on the 31st for inventory, back to it on Jan. 4.

Happy New Year, Ross!

Looking forward to getting my Engine with ECUs from Darren at Aerosport in early 2021!