- Sat Aug 24, 2019 5:56 pm
#37318
I'm going to try to use the speeduino on the homebuilt RV-4 two person light aircraft I built.
Before you hit reply to say "! DO NOT USE THIS ON AN AIRCRAFT !" I have a fully redundant ignition and fuel system. Aircraft engines already have two electrically independent ignition systems (they have always been unreliable, that's not a new thing) I will not remove one of the existing magnetos. The fuel backup is a 3-gallon-gravity-fed TBI from a manual valve in the cockpit. So this engine will continue to run (a little rougher), even with the electrical master switch off.
The engine that currently powers this aircraft is a mechanically injected Lycoming IO-320 of 160 rated horse power at 2700 RPM. It is air-cooled, horizontally opposed, 4-cylinder, normally aspirated of 320 cubic inch displacement. I am running a dual Garmin G3X Electronic Flight Instrumentation System (EFIS) with integrated Engine Monitoring System (EMS). That means all four cylinders are monitoring exhaust and cylinder head temp and I also have oil temperature (think H20 for air cooled), oil pressure, MAP, outside air temp, fuel pressure, fuel flow and tach.
I'm doing this project to achieve two goals;
- Efficiency; Far better dynamic fuel balancing from mass-flow-trimmed sequential fuel injection. The induction system is very imbalanced, and it is difficult to statically trim injectors. Also, dynamic spark advance is another 5% improvement in BSFC.
- Better and safer starts (especially hot)
- Simpler pilot operation (no mixture knob to manage or leave too lean/rich by accident)
- Better, cleaner, correctly-operating (detonation/pre-ignition) as the engine will always operating at ideal fuel/air mixture for the requested MAF/HP.
Non-goals:
- Speed/Power (it is what it is, I'm not a power wonk)
- Science project... not the place for it. Needs to just work
- Save money
My background... I'm a software engineer by trade. I have built a lot of cool stuff (like airplanes) and I enjoy DIY electronics. Not affraid of a transistor or a solder iron.
All that said... I've done a lot of research and I have questions....
1 - I need way to trim the injectors sequences in flight. Something really simple, maybe bluetooth to my phone even. I won't have to do this very often, but testing and long X/C, I'll want to tweak it while I'm flying.
2 - From clicking around Tune Studio, I have little confidence I can do an adequate job of getting a reasonable base map. Is there anyone here that might be able to help?
I have started a github on this project for me to collect my thoughts as well...
https://github.com/bruceme/aerosquirt/wiki
Thank you and I do look forward to feedback,
-Bruce
Before you hit reply to say "! DO NOT USE THIS ON AN AIRCRAFT !" I have a fully redundant ignition and fuel system. Aircraft engines already have two electrically independent ignition systems (they have always been unreliable, that's not a new thing) I will not remove one of the existing magnetos. The fuel backup is a 3-gallon-gravity-fed TBI from a manual valve in the cockpit. So this engine will continue to run (a little rougher), even with the electrical master switch off.
The engine that currently powers this aircraft is a mechanically injected Lycoming IO-320 of 160 rated horse power at 2700 RPM. It is air-cooled, horizontally opposed, 4-cylinder, normally aspirated of 320 cubic inch displacement. I am running a dual Garmin G3X Electronic Flight Instrumentation System (EFIS) with integrated Engine Monitoring System (EMS). That means all four cylinders are monitoring exhaust and cylinder head temp and I also have oil temperature (think H20 for air cooled), oil pressure, MAP, outside air temp, fuel pressure, fuel flow and tach.
I'm doing this project to achieve two goals;
- Efficiency; Far better dynamic fuel balancing from mass-flow-trimmed sequential fuel injection. The induction system is very imbalanced, and it is difficult to statically trim injectors. Also, dynamic spark advance is another 5% improvement in BSFC.
- Better and safer starts (especially hot)
- Simpler pilot operation (no mixture knob to manage or leave too lean/rich by accident)
- Better, cleaner, correctly-operating (detonation/pre-ignition) as the engine will always operating at ideal fuel/air mixture for the requested MAF/HP.
Non-goals:
- Speed/Power (it is what it is, I'm not a power wonk)
- Science project... not the place for it. Needs to just work
- Save money
My background... I'm a software engineer by trade. I have built a lot of cool stuff (like airplanes) and I enjoy DIY electronics. Not affraid of a transistor or a solder iron.
All that said... I've done a lot of research and I have questions....
1 - I need way to trim the injectors sequences in flight. Something really simple, maybe bluetooth to my phone even. I won't have to do this very often, but testing and long X/C, I'll want to tweak it while I'm flying.
2 - From clicking around Tune Studio, I have little confidence I can do an adequate job of getting a reasonable base map. Is there anyone here that might be able to help?
I have started a github on this project for me to collect my thoughts as well...
https://github.com/bruceme/aerosquirt/wiki
Thank you and I do look forward to feedback,
-Bruce