Last Update: Feb. 8/16
We have been supplying the experimental aviation market with engine management systems now for over 22 years. We offer aviation specific software and hardware for popular experimental engines and we fly what we sell. We are involved with several kit manufactuers, engine OEMs and alternative engine suppliers in joint R&D programs and in product supply.
We have provided aircraft EFI/EI systems for BMW, 3, 4 and 6 cylinder Suzuki, Continental, Lycoming, Franklin, Jabiru, LOM, Rotax, Saturn, Subaru EJ22, EJ25, EG33, EA82, EZ30, EZ36, Rotorway, Toyota, Hirth, HKS, Honda Fit, Honda V6, Rover/ Buick, Verner, VW, Jaguar and Mazda engines. These have accumulated over 375,000 flight hours on hundreds of aircraft and military UAVs all over the world in the last 22 years. Land based systems have accumulated an estimated 25 million hours of operation under widely varied and sometimes severe conditions, including the famous Baja desert races with extreme heat, pounding G forces and punishing vibration levels. We have been flying an RV6A powered by a turbocharged Subaru EJ22 engine for product development purposes now for 12 years. We were the first to have a Gold Championship win at the Reno Air Races with EFI in 2010. We have approval with the UK LAA on the Titan T51 and RAF 2000 gyrocopters and are working with customers in the UK on additional approvals for other experimental engine/airframe combinations. Racetech/SDS has more aviation experience with EFI on a wide variety of engine types than any other company and is the leading supplier of aftermarket EFI/EI systems for experimental aircraft worldwide. Much R&D is now focused on aviation specific improvments for traditional air cooled aircraft engines such as Lycoming and Continental. As of 2012, the aviation market has become our primary one, supplanting the automotive side. We're the only company currently manufacturing dedicated, dual redundant EFI/EI ECUs specifically designed for legacy, Experimental aircraft engines. SDS is the only aviation ECU offering cockpit adjustable, individual cylinder fuel trim for optimized LOP operation (4 cylinder only at this time). Watch this page for the introduction of new features under current development.
Turbo Subaru powered RV6A and RV7. Both equipped with SDS engine management systems. The yellow RV6A is our company test aircraft with over 400 hours on it now.
Jeff Ackland's LS V8 powered P85 is equipped with an SDS EM-5 8D engine management system. Flying in Kansas.
Basic components of generic distributorless EM-5 4F aviation system
Many aircraft engines have poorly designed intake manifolds with different runner lengths, different entry angles and small plenum volumes. This usually results in unequal airflow to each cylinder and therefore unequal air/fuel ratios in each cylinder. This leads to roughness and the inability to run far lean of peak, since one or more cylinders gets to the lean misfire point before the others. EGT spreads of over 200F are not uncommon. There's little you can do about it with a carb and the old fashioned way of correcting it with antiquated Bendix/AFP mechanical injection systems was tailored nozzles but this can only work well at one rpm and power setting. With optional SDS V26 software, users can now trim the fuel amount +/- 10% in 1% increments to equalize all cylinders AFR and EGTs from the cockpit as shown in the photos below:
To change your AFRs in flight, check your engine monitor EGTs and call up these windows in your SDS programmer. Increment or decrement fuel trim with the +/- 1 buttons, scroll left or right to the next trim window with the < or > buttons. It's that simple and makes screwing around with changing nozzles a thing of the past. You can also trim fuel at any throttle angle, MAP or rpm so you are not stuck with an imbalance like you are with mechanical systems. LOP operation is now fully optimized for best power, smoothness and fuel economy and zero GAMI spread.
Recent flight testing allowed the user to get all cylinders to peak simultaneously and the engine would run smooth right to 200LOP. An 11% trim variation between leanest and richest cylinders was required.
Available for 4 cylinder engines only at this time
Not applicable to EM-1 to EM-4 ECUs. EM-2 through 4 ECUs can have an EM-5 board installed to get this capability. Older EM-5 ECUs can be upgraded to this capability for $350US starting in Feb. 2015. For applications revving under 4500 rpm, you'll also get 100rpm increment fuel and spark programming as well, replacing the 250rpm steps on older systems with V26 software. This gives even finer control of base mapping for direct drive engines operating below 4500 rpm. Simple wiring changes are required on older models to take advantage of the fuel trim software, matching ECU output pins to specific injectors.YouTube video showing trim functions
Basic ECU Specs
Size- 8.5 X 4.0 X 1.0 inches/ 22 X 10 X 2.5cm
Weight- 15.8 ounces/ 450 grams (single)
Current draw at 14.5V- 0.3 amps (no programmer), 0.6 amps with programmer plugged in
These products do not conform to any recognized set of standards or certifications for aviation applications.
This ECU is not waterproof and will not function as designed if moisture invades the enclosure or power/ ground connections are interrupted. Failure of this unit may result in a complete loss of engine power.
Use of these products on amateur built/ experimental aircraft is at the discretion of the buyer who accepts full responsibility for any consequences resulting from its use. Since Racetech Inc. cannot control the installation, programming, application environment or use of its products, we accept no responsibility for damage, loss or personal injury resulting from the use of SDS products. By using SDS products, the user understands and accepts this.
If any user does not agree to this disclaimer, they may return the system/ parts in new condition for a full refund.
Cheap Chinese Ripoffs
It's come to our attention recently that a company in China is selling EFI systems named SDS. This same company has also plagiarized ad copy and technical content directly from our website. Be aware that they are not affiliated with us in any way.
Photo of aircraft 3 1/8 panel mount display head (backlit). With V17-25 software, has 4 gauge modes to display, manifold pressure, rpm, engine temperature, induction temperature, battery voltage, fuel flow, injector duty cycle, throttle position, acceleration enrichment, mixture knob position, ignition timing and O2 sensor voltage. Also displays error codes for sensor failures, check engine light feature and allows full programming of the system in flight.
Dual fuel pump module with integrated filter. Original design by Ross Farnham and Trevor Colebank, now copied by another company. The gold standard for aircraft fuel pump modules. Pumps may be reversed to put integral filter on pressure side if desired. See more info at the bottom of the page or click here pump module.
Because people often want different parts or to delete some parts from kits, we cannot put every combination with pricing on our order pages. Please contact us so we can finalize what parts you want, wiring harness lengths, preferred terminations and shipping costs: E-mail:email@example.com
Advantages of SDS Over OE EFI Systems in Aircraft
While there are many automotive engined homebuilt aircraft flying with the OE computer controlling fuel and ignition successfully, many users may not be aware of some potential pitfalls of using these systems. Many OE computers can either shut off the injectors if certain things fail such as a water temperature sensor to protect the engine from a perceived or real overheating condition or go into a very low power limp home mode. Either of these scenerios mean that you are coming down in an aircraft. The designers of these automotive ECUs did not take aircraft use into account during the design phase obviously. Their considerations were likely as follows, in order of importance: 1. Reliability- keep the engine from destructing ( shut the injectors off if necessary), 2. Emissions, 3. Fuel economy, 4. Driveability, 5. Power. Fortunately modern EFI systems, sensors and ECUs are very reliable, generally speaking. Just be aware, that as on your Continental or Lycoming, anything CAN fail equally so on your automotive/EFI conversion, making you an unwilling glider pilot.
Many people have spent countless hours trying to unravel programming code on OE ECUs for use on aviation applications, to undo unsuitable code or responses or security interlocks sometimes successfully, sometimes not. Others wonder what the ECU might do when certain sensors or inputs are modified or disconnected, especially many of the tied in chassis sensors on modern systems, not to mention security and digital key interfaces. What some people have attempted to do in dozens or hundreds of hours with often unknown consequences using OE ECUs can generally be done in minutes with SDS. You know exactly what the system will do without any hidden secrets or repercussions. All OE ECUs were designed to use an O2 sensor for closed loop feedback of the air/ fuel ratios at part throttle. As such, they may not be very suitable for use with leaded avgas. SDS does not require an O2 sensor at all.
People using OE systems often have to use the factory car wiring harness which obviously was not designed to fit their airplane. They try to strip out wires which are not needed, lengthen this, shorten that. Usually they just have a big, stiff, heavy, ugly mess on their hands. With SDS, we build a custom, lightweight, reliable harness for your installation. We can leave connectors off for easier firewall passage and can even provide a harness with no pins on so you can custom tailor each cable yourself. We use tinned wire on all our harnesses so it's not subject to the oxidation that you see in many OE automotive harnesses over time- even inside the insulation.
Typical auto OE wiring harness
SDS wiring harnesses. Note separate harnesses for sensors, options and injectors
Disadvantages of SDS vs. Conventional Aircraft Engine Systems
The big disadvantage of EFI compared to a carb or mechanical injection and magnetos is that electrical power is required for the pump, computer, ignition and injectors. The likelihood of both the alternator and battery failing simultaneously is practically zero with standard aircraft maintenance procedures. Generally, a good battery will allow you to keep essentials powered for 20-90 minutes after an alternator failure permitting diversion to another airport. We consider proper gauges and/or warning lights to indicate an alternator failure to be very important. We have an ammeter, voltmeter, low voltage warning light and buzzer now on our RV6A and also added a backup battery in Feb. 2005.
Advantages of SDS vs. Conventional Aircraft Engine Systems
Virtually zero maintenance, lower fuel flows due to better mixture distribution, automatic mixture control, no carb heat, smoother running, no mag checks, no live mag issues, longer engine life due to proper mixture control and less bore washing are some of the major benefits of EFI.
Why should I consider SDS over other brands of EFI for my aircraft?
1. We have more experience than any other company in this field with an unmatched track record on many diffrent engine types including the 2010 Super Sport Reno Gold Championship winner.
2. Our basic designs are also used in automotive applications so we have a huge amount more hours and customer feedback to quantify reliability than aviation only sytems.
3. We fly what we sell and are actively involved with the aviation market.
4. Our systems are designed to keep the engine running at close to full power even with multiple sensor failures unlike many other systems which may shut the engine down or OEM systems which will go into a limp mode, not allowing enough power to maintain flight.
5. We have the best tech and customer support in the industry.
6. Systems are individually tailored for your engine with realistic base programs and custom length wiring harnesses (either terminated or unterminated for easier installation and firewall passage). You won't struggle making wiring or trying to start your engine like with most other systems which just come in a box.
Quick Aviation Q&A
Q. What about redundancy?
A. On twin plug engines, it is posible to retain one mag and add a fuel nozzle into the plenum as a backup. For pilots who are not comfortable with this idea, we can offer dual ECUs. The dual ECU can also be used on automotive V8 and V12 engines in a split bank configuration, with one ECU running one bank of the engine each. We treat a V8 as 2, four cylinder engines sharing a common crank and a V12 as 2, six cylinder engines sharing a common crankshaft. Each ECU would have it's own sensor suite.
Dual board aviation ECU. Weight is 1.5 lbs.
New aircraft programmer internal programmer selector option for dual ECUs
Miniature toggle switch selects primary or backup ECU for reprogramming. Option available Oct. 30/15
Relay switch box for dual ECUs to switch injector outputs between primary and backup ECU
Q. How about low voltage conditions after an alternator failure?
A. The EM-5 ECU will continue to operate down to 7.3 volts as shown in the photo below when most other electronics and avionics have given up the ghost at around 9 volts
Dual Hall sensor pickup
Q. Are the aviation units any different from the automotive ones?
A. SDS was originally conceived as an automotive system so most of the electronic hardware is identical. The advantage of this compared to units developed specifically for aviation is that we have accumulated several million hours of operation due to the greater numbers in automotive service where conditions are usually more severe. Hardware differences would be things like the aviation programmer, coil packs, dual ECU box, crank sensors/ mounts are different. Software differences include MAP calibration in inches of Mercury absolute, revised acceleration enrichment code which also improves cold starting and special programmed defaults to help minimize the effects of sensor failures. We sell far more ECUs for aviation now than automotive so have blended all the lessons learned into all ECUs. Our strategy has always been to keep the engine running at near full power even with multiple sensor failures-especially important in aviation.
Q. What use is the mixture knob on an automatic aviation system?
A. We recommend the mixture knob be panel mounted in all aircraft to allow the pilot to make a mixture adjustment in case of certain sensor failures. This gives you independent control of the mixture from the programmer. Some pilots prefer to manually lean with the knob once cruise power is set also.
Q. How do I start to tune SDS on my aircraft?
A. All systems have a base map entered if we know your injector flow rate and engine displacement. The engine should start and idle for you first time. The mixture knob allows instant mixture adjustment +/- 50% so you can get a smooth idle right away while the engine warms up. By using the optional wideband air/fuel ratio meter kit which displays the AFRs directly in the SDS programmer screen, you can observe and correct the AFRs at each rpm point with the aircraft tied down while slowly advancing the throttle. Main programming only takes about 10 minutes for most engines. Programming for cold start can take longer as you must have the engine cold at each engine temperature to be able to observe and correct the values. As of Oct. 2014, 8 channel data logging to a PC is an available option.
Some useful tuning information here aimed towards Subaru installations but generally applicable to other auto conversions: Aircraft Engine Tuning Guide
Lycoming Engine Tuning Guide
Tuning guide for Lycoming installations
Low cost wideband kit. Imbedded controller, 4.9 LSU sensor, wiring harness and stainless boss $145. Simple hookup. AFR displayed in SDS programmer. Highly recommended for tuning your SDS. No dealer discounts on this item.
Operation on either 100LL or Mogas is possible as no O2 sensor is required for operation. Automatic mixture control with altitude is standard as is the option to lean manually with the standard mixture knob. Many people prefer to manually lean via EGT once cruise altitude and power is set.
These systems are designed to use either the factory injectors or other standard automotive style injectors. We can supply injectors, pumps and regulators for most aviation applications.
We can supply systems for most 4, 6, and 8 cylinder automotive engine conversions. With SDS you have the option to manually lean or let the computer take care of things automatically. The EM-5 ECU has very low RF noise output and the elimination of carb heat makes operation simpler, safer, cheaper and lighter.
11/20/00 Knock Sensors on Aircraft
We don't usually recommend the use of knock sensors for engines powering aircraft. Generally speaking, air cooled engine have too much mechanical noise to be able to filter it out and "hear" the knocking. The second problem on opposed engines especially, is placement of the sensor. Most auto manufacturers spend countless hours determining optimum placement. You probably can't. The third concern is that the engine needs to actually knock before the ECU retards the timing which isn't good for it. Fourth, if you have the sensitivity set wrong, the ECU may retard the timing the full 25 degrees because of mechanical noise. You would lose over 25% power and this could cause an accident. Extremely high EGTs could also damage the engine. Finally, if you are running on 100LL and have reasonable manifold pressure limits, compression ratio and ignition timing, the engine won't knock in the first place. SDS does have knock sensor capabilty which may be useful for liquid cooled automotive engine conversions where factory knock sensors exist and careful setup procedures sre followed.
Wiring and Modifying Systems
We get many aircraft owners who either want to do their own wiring harness or modify our systems in some way. Over 75% of the people who do these things have problems or burn up the ECU. Our advice is DON'T. Unless you do wiring for a living, this is simply a bad idea. People want to put cannon plugs at the firewall to make engine removal easier. Why? There are only about 5 connections to the engine and four are quick disconnects. How often are you pulling the engine? Even a total hab case can disconnect these plugs in 10 minutes. Every time you add another connection, you add another potential place for a fault to occur. If it ain't there, it can't fail. Some of the wiring that we have had returned to us is an absolute joke for an aircraft. Downright dangerous. If you modify the wiring or the system, don't bother calling us if your pride and joy ends up in the trees. Our system has proven to be extremely reliable if installed and operated as designed. Please use your noggin here.
Here is an example of some actual aircraft wiring returned to us. This is just waiting to break or short to ground. Proper strain relief and insulation is imperative for reliability.
We highly recommend that all EFI harness wires be run separately from other wires which carry high current/ voltage or any type of pulsing current signals. It has been shown that wires run parallel to each other in this fashion can lead to EMI and inductance coupling which may cause ECU running problems. Generally run the EFI wires through one side of the firewall and all other wires through the other side.
For Lycoming, Continental, Jabiru and Rotax four cylinder, dual plug engines, we can supply these lighter weight coil packs which save about 1.25 lbs. each over our standard coil packs.
Small style injector bosses available with steel or aluminum bases. Threaded for 1/8 NPT fuel inlet fittings. Suitable for Lycoming, Continental, Rotax and Jabiru installations. Require TIG welding to attach to induction tubes.
Production bosses in steel and aluminum for Jabiru, Rotax, Lycoming and Continental engines
Available with top feed or dual side feed tops
Billet 80mm throttle body to replace Bendix RSA-10 and AFP FM-300 servos when converting to EFI. Horizontal mounting.
Air horn accepts 3.5 inch SCAT hose, 3.5 inch ID K&N filters or 3.5 inch ID Silicone hose couplers. 6061T6 construction, stainless steel shaft riding on sealed roller bearings, 7075T6 throttle arm, brass butterfly, accepts OEM Bosch TPS, O-ring sealed air horn to body and flange to sump. Under 2 pounds and only 3.625 inches high. Integral throttle stop. Stainless hardware.
Billet 45mm throttle body designed for engines in the 60-120hp range. Common applications would be VW, Conti O-100, O-200, Jabiru 2200, 3300, Subaru EA81, Suzuki 1.3/1.6, Rotax 912 etc. The body is 6061-T6, throttle arms are 7075-T6, shaft is 304 stainless and blade is brass. Arms are available for either vertical or horizontal mounting. Optionally mounts a genuine Bosch TPS. The engine side has an O-ring groove for sealing and is mounted with AN3 bolts. Air side snout is 2 inches OD to take common K&N filters or SCAT tubing. Weight as shown with TPS is 240 grams. Can be anodized for a slight extra charge if desired.
Here are a few photos of the 45mm TB anodized
60mm generic throttle body available for engines up to 200hp.
We stock top quality Aeroquip and Earls fittings, filters and hoses now
Genuine Walbro pumps, made in USA
Quality Borla AN6 fuel pressure regulator, made in USA
New fuel block with integrated fuel pressure regulator. 1/4 NPT inlet, four 1/8 NPT outlets plus one 1/8 NPT port for fuel pressure tap
Same block as above but with 1/4 NPT inlet and outlets for externally mounted regulator
The Gold Standard
Racetech dual pump module. Mounts twin genuine Walbro pumps. Anodized 6061T6 body resists oxidation and corrosion, 7075T6 fittings are double O-ring sealed (genuine Viton) for ultimate strength and reliability, straight flow path without restrictive banjo fittings, integrated sintered bronze filter which is easily inspected, cleaned and replaced. Mounts drilled for AN3 bolts- unthreaded, a variety of 1/4 NPT ports available for different fuel line connections and pressure measurement, stainless steel hardware. Price $625US with pumps for up to 300hp. $680US with pumps for up to 400hp. Approx weight as shown- 3 lbs./ 1370 grams. Supplied with 4 1/4NPT plugs. No dealer discounts on these items. This is our original design and others have copied it now.
Module shown with optional fuel pressure regulator mounted to avoid mounting the regulator firewall forward.
Regulator and mount kit $255
Note we use only genuine, made in USA Walbro pumps, genuine made in USA Borla regulators and US made filters and AN hardware- no cheap Chinese copies/ ripoffs. Body designed, machined and anodized in Canada. We support jobs and industry in North America as much as possible.
We can supply many individual components and kits for EFI/ EI conversions. We believe each installation is custom and will tailor systems to your individual needs. Because of the variations in airframes and parts/ installation preferences we don't publish all kit prices here. It's better to contact us via email to work out what you want and need for your particular installation. We can quote you from there. E-mail:firstname.lastname@example.org
How good is the spark on SDS ignitions some might ask? Here's a photo of an actual, badly oiled up plug removed from an SDS equipped engine. The ignition was still firing this one consistently with no misfire.
More info here: CPI
Lycoming 320/360 ignition kit includes Magneto cover(s), single or dual Hall sensor and mount, hardware, automotive plug adapters (1/2 reach) and plugs plus drilling block, drill and tap to mount magnets into OE flywheel, panel mount kit, MSD 8.5mm wire sets and wiring harness also included (not shown). Fits engines with 8 7/16 ID flywheel only. $1185US. Wiring harnesses can be custom tailored to your needs and any items not desired can be deleted from the kit. Note, you must drill and tap your own flywheel for the triggering magnets.
Rear coil mount for 4 cylinder Lycoming engines. Mounts to magneto studs.
CPI-6 coil pack, crank sensor installation on Mike Robinson's Lycoming IO-540 powered Rocket
We have more parts currently under development for the Lycoming kits for a wider range of fitment and coil mounting options. Watch this spot and the CPI Page for more information.
Aircraft/ Engine Forums
Jan. 15/15 Service Bulletin Regarding Vertical Power VP-X and SDS
It has come to our attention that the VP-X electronic switching/ circuit breaker box does not use average current draw over several seconds to trip breakers like conventional thermal breakers do. It may trip during normal operation due to peak current transients over only a few milliseconds. This can lead the pulsing current of the ignition coils and injectors to trigger the breaker far below nominal current levels. We believe this could cause a serious flight safety issue and engine stoppage. Be sure to set the breaker values on the VP-X far higher than the nominal current draw on these circuits. Be aware that average current draw can increases with rpm and load so ground running may not allow complete testing of this condition if static rpm is lower than flight rpm and engine shutdown could occur in flight. Breakers are to protect the wiring, not the device. We recommend each 4 cylinder coil pack have a rating of at least 15 amps assigned when using the VP-X, each 6 cylinder coil pack at least 20 amps, 4 cylinder injector power at 15 amps, 6 cylinder at 20 amps and 8 cylinder at 25 amps. These are only recommendations, use this information at your own risk and these values should be thoroughly tested prior to flight at WOT and maximum rpm the engine will see in flight.
Oct. 20/15 Service Bulletin Regarding Thread Sealant on Fuel Fittings
RTV (silicone) must NEVER be used to seal threaded fuel fittings. We recommend Permatex High Performance Thread Sealant for use on pipe thread fittings. This must be applied SPARINGLY to ONLY THE MALE FITTINGS, NEVER THE FEMALE ONES. Once sealant is applied, screw the fitting in until tight. Never unscrew fittings without throughly cleaning all traces of sealant from inside the fittings and threads before re-assembling as this can dislodge sealant which can clog passages further downstream leading to possible fuel starvation. Never apply sealant to joints with flat crush washers or O-rings.
Aircraft Related Tech Articles and Projects:
Racetech's RV6A Project
Suzuki G13 Hall Sensor/ Magnet Mounting Instructions
Auto Engines in Aircraft Part 2
Racetech's RV10 Project
Subaru Powered Dragonflies
Suzuki Powered Snark
C-85 Powered Dragonfly
Metro/Tracker Powered Jenny and Spad Replicas
Thoughts on Redundancy
Auto vs. Certified
EJ22 Intake Manifold
EJ22 Alternator Mount
Vacuum Pump Mounting
Cylinder Head Flow Benching
13B Powered Lancair 235
Justin Mace's Continental Powered Dragonfly
Bill Baxter's EJ 22 Powered Glastar
EJ22 Powered Europa
John Petrie's EG33 Powered KIS Cruiser
Gordon Wardstrom's Rover Powered Bearhawk
Joe Block's Lycoming Powered Glastar
Subaru EG33 Intake Manifold
Subaru vs. Lycoming (the unabridged version of the April 2005 Kitplanes article.)
Deadstick Technique for RV Pilots
Backup Battery Considerations
Auto Aircraft Engine Tuning Guide
Lycoming Engine Tuning Guide
EFI vs. Carb
SDS products are manufactured, supported and sold by:
Racetech Inc. E-mail:email@example.com
CLICK ON LINKS BELOW:
#5-304 Noorduyn Park
Calgary, Alberta, Canada
Phone 403-671-4015, Fax 403-453-7687
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