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Sales phone number 403-671-4015


Last update March 17/24

***Please note that SDS Aero products are only for use on Experimental/ amateur built aircraft. Not for use on certified aircraft.***

SDS CPI (Coil Pack Ignition)(Aviation Applications)

Programmable aircraft electronic ignition system. See new CPI-2 here: CPI-2 See automotive CPI info here: CPI

Keypad/ module

Lightweight, simple, feature packed, easy to use, programmable aircraft electronic ignition

The CPI is a programmable, stand alone, crank triggered, distributorless ignition system for 4, 6 and 8 cylinder engines. The primary target market is aviation engines equipped with carburetors or mechanical fuel injection. Comes complete with coil pack, crank sensor, magnets, wiring harness, vacuum hose, manual. Compared to older aircraft electronic ignitions, the CPI is smaller, lighter and has more features. The CPI is user programmable (in flight if you wish) via the integrated keypad. No PC required, no extra cost, 3rd party programmer, no scheduled maintenance to perform. Easy to advance timing when running Lean of Peak for maximum power and fuel economy.

Kit prices start at $875US for some basic 4 cylinder engines like Jabiru 2200 and Rotax 912(single coil pack, without plug wires). We'll tailor wiring harnesses and optional items to suit each customer's specific requirements. Best to email us here for your needs and a quote: racetech1@telus.net Please note that these prices are not for the automotive kits that we also offer here: CPI

Electronic Ignition Kit Price Comparison USD (as of July 2019)

As of Jan. 1/23 CPI prices are $1193US for single 4 cylinder Lycoming, $1333 for single 6 cylinder Lycoming

Please note, the CPI is not suitable for hand propped engines, you must have a starter

Complete Lycoming 540 kit. System prices range from $1333US for single systems driving one set of plugs or $2486 for dual system driving both sets of plugs, depending on options. On engines with long reach plugs (identified with yellow center head finning), add $102 per system for longer plug adapters and Denso Iridium plugs.

Spark plugs and adapters for long reach Angle Valve Lycomings (IO-390/ 580)

Rotax 912 single CPI kit

CPI Features

  • CPI gives you complete timing control with rpm (100 rpm increments on direct drive engines) as well as manifold pressure (boost retard and vacuum advance)
  • Logical, 1 degree programming increments for all parameters
  • Small size- 4.4 X 2.35 X 1.2 inches for module
  • Clean, compact design
  • Integral MAP sensor
  • Rev limiting
  • Backlit LCD has gauge mode to display rpm, manifold pressure and actual ignition timing
  • 12V tach output
  • Programmable dwell time and cranking retard values
  • Single CPI module can drive two coil packs for twin plug, 4 cylinder engines (Continental, Lycoming, Jabiru 2200, Rotax 912/914 etc.)
  • Based on proven SDS EM-5 and XIC software/ hardware, over 20 years experience and thousands of systems in service worldwide
  • MAP units display in inches of mercury absolute
  • Aviation panel mount kit available
  • Low current draw/ long spark duration. 4 cylinder coil pack and CPI draw about 1.2 amps at 2500 rpm.
  • Aviation CPIs have a switch to alter advance with mixture strength for best LOP cruise economy or swiching between mogas and 100LL.
  • Magnet alignment screen and LED for fast crank sensor setup, error warning for missed magnets/ alignment issues
  • Coil test mode
  • Runup test for twin plug aviation installations
  • Simple wiring hookup, Wiring harness included made from Mil Spec Tefzel wire.
  • Hall Effect triggered- no timing disc to mount. Flying magnets (supplied) can be mounted to crank pulley or flywheel
  • Magnets are crankshaft mounted so timing is precise, no worries about magneto gears, drives, bearings, oil seals wearing or failing
  • Never any "Lost Timing" scenarios as with other EI brands
  • No chance of engine kickback when starting
  • No electronics mounted inside hot engine parts like many other aircraft EI systems
  • No cooling blast tubes required like many other aircraft EI systems
  • No periodic inspections on mag gears, cotter pins, bearings, shafts, seals, PCBs like P-mag. Just check spark plugs during annual
  • No coil failures like on some of the competing brands
  • All components firewall forward are waterproof unlike some other aircraft EIs
  • Our circuit boards are conformal coated in key areas to resist humidity, condensation and oxidation unlike some EIs which have bare boards
  • Coil packs are engine mountable
  • Bolt on kits for Experimental Lycoming 4 and 6 cylinder, Jabiru 2200/ 3300, Rotax 912/914 engines
  • Variety of coil pack mounts available for Lycoming engines- (top case, mag hole and firewall)
  • Unit can be blind or panel mounted
  • Lower price than other aircraft EIs. Single 4 cylinder CPI with all options and short reach plugs- $1170.
  • Racetech/SDS has been selling EIs to the aviation market since 1997. We've built our reputation and business on reliable, affordable products and the best customer and tech support in the industry. You'll find us friendly, helpful and timely in our responses before and after the sale and we don't make promises we can't keep.
  • Note the CPI should only be used with resistor type spark plugs and good quality, EMI/ RFI suppression type plug wires. Never use non-resistor plugs or solid core wires. We can supply quality MSD plug wire, boots and terminals for most engines.

    The Lean of Peak Switch Advantage

    While other aviation EIs give you a canned timing curve which is often secret and hard to adjust, usually requiring extra cost options to observe and change, SDS CPI makes basic timing adjustments quick and easy to do and our LOP switch optimizes ignition advance when running LOP. This feature extracts all possible energy from the fuel, picking up a few knots which are lost when running leaner mixtures.

    The figure below illustrates how combustion flame speed changes with air/ fuel ratio.

    Notice how much flame speed slows down with lean mixture here. The SDS LOP switch advances timing when you are running LOP to achieve peak cylinder pressure at the optimal point for best torque.

    Notice how advanced or retarded timing affects the pressure vs. crankpin position curve. Unlike magnetos with fixed timing, CPI can deliver optimal ignition timing under all mixture, rpm and load conditions. EIs which cannot adjust timing when running LOP, lose efficiency compared with CPI

    A couple videos showing basic features and programming and CPI hardware:



    Video of Magnet Position set up on a Lycoming engine: https://www.youtube.com/watch?v=6-7K-GA35f4&feature=youtu.be

    Lycoming 320/360 ignition kit includes Magneto cover, single or dual Hall sensor and mount, hardware, automotive plug adapters and plugs plus drilling block, drill and tap to mount magnets into OE flywheel, optional panel mount kit, MSD 8.5mm wire sets and wiring harness also included (not shown). Fits engines with 8 7/16 ID flywheel only. Prices range from $1120 to $1170US for a single setup firing one set of plugs, $1965 to $2185 for dual setup firing both sets of plugs, depending on options. On engines with long reach plugs (identified with yellow center head finning), add $68 per system for longer plug adapters and Denso Iridium plugs. 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 with the drilling kit provided.

    Please note: our magnet mounting system for Lycoming engines is not compatible with the Sky Dynamics lightweight flywheels, new Lycoming flywheels lacking the 12 tooling holes around the periphery or factory dual pulley groove flywheels. We do have a solution for Airflow Systems aftermarket flywheels for driving a/c compressors.

    Photos showing some of the basic screens here:

    Advance switch screen

    Magnet alignment window

    RPM timing advance window

    Manifold pressure advance window

    Manifold pressure retard window

    Programming resolution is 1 degree. Timing values are shown in true degrees. Full control given to the user over the entire timing map from cranking retard to rpm (every 100 rpm) to MAP (every 1.2 inches) plus advance switch amounts. No clumsy, extra cost programming interfaces like Lightspeed, P-MAG offers.

    You must have the larger 9.75 inch OD Lycoming flywheel to mount our magnets and crank sensor.

    ID near belt groove should measure 8 7/16 inches.

    OD of belt groove should measure 9 3/4 inches.

    Coil mount kit for 4 cylinder Lycoming engines. Mounts to top rear of crankcase. Does not fit narrow deck engines. See photo below.

    For reference, this is what a narrow deck Lycoming case looks like. Note deep recesses for top case bolts.

    Top case coil mount on wide deck engine.

    Rear mount for coil packs on 4 cylinder Lycoming engines. Mounts in place of magnetos.

    540 top coil mount

    ***Please be sure to measure your front case bolt spacing on Lycoming engines before ordering. This dimension can be either 3.25 or 3.50 inches.***

    Replace your crude factory Rotax ignition with CPI. New lightweight Rotax 912/914 magnet disc and Hall sensor mount. Dynamo ring not included.

    Jabiru 2200/3300 Magnet disc and Hall sensor mount

    For aircraft system pricing, options and wiring harness lengths and termination preferences, please contact us:


    Subaru type coil pack supplied for 4 and 8 cylinder engines and twin plug, 4 cylinder engines

    Coil pack supplied for 6 cylinder engines with module, mounting bracket and heat sink. 3.6 pounds

    Underside of CNC'd mounting bracket, 6 cylinder

    Coil mounting hardware kit included

    LCD shown in gauge mode

    Optional Panel Mount Kit

    Panel mount blocks on CPI

    Blocks, hardware and drilling/ scribing template

    Block detail

    Template over CPI face

    Approximate System weights

    Single 4 cylinder CPI driving one set of plugs- 4.5 pounds

    Single 6 cylinder CPI driving one set of plugs- 5.5 pounds

    Dual 4 cylinder CPI driving 2 sets of plugs- 8.5 pounds

    Dual 6 cylinder CPI driving 2 sets of plugs- 10.5 pounds

    Note that there are slight differences in coil mount weights

    MSD Plug Wires and Boots

    Be sure you push the plug and coil boots all the way down to engage the terminals fully. There should be about a 1/8 inch gap as shown in the photo below

    MSD Plug Wire Part Numbers

    The following bulk PNs fit all coil packs:

    34049 8.5mm red Superconductor wire
    34615 90 degree terminal (plug and coil)
    34555 90 degree coil boot
    34515 90 degree plug boot

    Recommended MSD plug wire crimping tool PN 35051

    Video for building your MSD plug wire set

    Customer Install Photos

    Carlos Lopez's immaculate Lancair Legacy in Argentina, dual CPI equipped

    See multiple installation and aircraft photos here

    Tim Wall's amazing 70% Spitfire scale replica. Buick 3.5L V8 powered.

    Hall sensor installation

    CPI controller

    Coil pack installation

    LS powered Few Mustang

    Install on VW engine

    Photos of nice install on O-360 Lycoming from Karsten Lorenz

    Clean CPI install on Paul Dannebrock's RV-9A

    Hall sensor mount detail

    Coil pack mounted in right magneto hole

    CPI flush mounted to panel

    Dual CPI install on Mike Kellems' RV-3B

    Dual CPIs mounted on fold down, hinged panel

    SDS billet flywheel and coil mounting detail

    Hall sensor mounting detail

    Marv Wessel's award winning Lancair ES fitted with dual CPIs

    CPIs mounted behind panel

    CPI coil pack installation on Ivan Kristensen's RV10

    Hall sensor cable armoring detail

    Temporary pointer installed to set Magnet Position

    CPI-6 coil pack, crank sensor installation on Mike Robinson's Lycoming IO-540 powered Rocket

    Flywheel detail on IO-540

    Crank sensor mount detail on IO-540

    Adam Pontious' very nice Rocket with CPI

    Photos of Hall mount for 3.50 inch case bolt spacing

    3.25 inch spacing Hall mount. Both designs now have threaded holes to mount cable protection plate to.

    Dual CPI panel installation in Steve Alderman's Lancair

    Steve Alderman's Lancair

    Lycoming 540 rear coil pack mount

    Rear coil mount on Lycoming O-320

    Simon Jarman's lovely O-320 powered Glastar in France with CPI-4. Nov. 2016 update from Simon- "...I have been running your CPI unit for 8 months, and so far it is a fix and forget solution. The engine always starts hot or cold and there is no rpm drop on turning off my magneto, so the CPI seems to be doing all the work. I am saving some fuel too. On a recent trip to Spain at 8000' I averaged 19.6 mpg out and 21.4 mpg back, difference due to wind. Previously I was seeing about 18 mpg"

    Crank trigger detail on Lycoming 360/ Lancair

    Firewall mount of CPI coil pack on Neil McLaren's RV6, Aerosport 375 engine

    Here are some installation photos on a 360 Lycoming done by Ralph Inkster on an RV.

    Crank sensor mount and cable shield detail

    Sensor cable penetration of baffling

    Top coil pack mount. This saves penetrating baffling with spark plug wires

    Crank sensor cable routing

    Hinged CPI mount under panel in retracted position

    In extended position

    End view retracted position

    Some photos of Sam Spanovich's Revmaster 2100 powered KR2S with SDS CPI

    Crank sensor mounting detail

    Some photos of Calvin Thorne's CPI installation on his VW powered Quickie

    Calvin Thorne VW Quickie Page

    CPI Documentation

    For main aero CPI installation and tuning manual click here Revised April 4/22

    For CPI aircraft supplement guide click here Revised Mar. 20/22

    Lycoming 4 cylinder magnet mounting Revised Oct. 23/19

    Lycoming 6 cylinder magnet mounting Revised Oct. 23/19

    Basic wiring and switch layout for dual 6 cylinder CPI

    Video on CPI internal Spark Test Function

    Service Bulletins

    Sept. 2/19 Setting Magnet Position

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

    April 26/19 Service Bulletin Regarding 18 to 14mm Spark Plug Adapter Installation

    Due to a number of broken brass plug adapters, we've changed the procedure for installing these as follows: 1. Thread the spark plug into the adapter 2. Torque the assembly into the cylinder head using the PLUG hex to 19 ft./lbs. 3. Torque the ADAPTER further to 25 ft./lbs. Use only a thin stripe of anti-seize compound on the plug and adapter. Do not coat the threads. Although we've done multiple yield tests on the adapters torqued into a fixture and they fail at 32-35 ft./lbs., a number of people were snapping them at the originally recommended torque of 22 ft./lbs.

    Magneto Parts to Remove on 6 Cylinder Lycoming Engines

    Exploded view of magneto parts on Lycoming 540 engines: 540magparts.pdf
    When replacing the mags on 6 cylinder Lycoming engines, be sure to remove the gear/ cup (6), cush drive (2) and pilot bearing (7) as shown above. Be very careful not to drop any of the parts into the sump! The extension housing (4) may be removed or left in place as desired

    For other aviation product information, click here: Aircraft

    | Home Page | Product Specifications | Programming and Installation Manuals | SDS Advantages | Price List/Shipping | Dealer List/Links | Tech Page/FAQ | Project Page | Sample fuel maps | About Racetech | CPI-2 | Hardware | Aircraft |