Autosport Labs developed its standalone MegaJolt ignition system. It is a fully computerized ignition system meaning that you can program any amount of ignition timing based on RPM and load (manifold vacuum). The MegaJolt ignition system is based on the crank-triggered Ford EDIS (Electronic Distributorless Ignition System) and your distributor is no longer used. Since MegaJolt relies on Ford EDIS components, you can save money on the conversion by sourcing used parts.
The MegaJolt ignition system is ideal for dual fuel applications because the ECU allows the use of two ignition maps that are selectable with an external switch. The system is configured with a free downloadable software from Autosport Labs and there is support available through MegaJolt discussion forum.
This ignition system requires technical expertise and is not a bolt-on upgrade. See MegaJolt Documentation
Components required for this ignition system are:
- MegaJolt Ignition Controller
- Ford EDIS Module
- Trigger Wheel & Crank Sensor (plus mounting brackets)
- Coil Packs (1 required per pair of cylinders)
- EDIS sparkplug wires
- Laptop computer & USB Cable (for configuration)
The Ford EDIS is a waste spark ignition system, meaning that it a distributorless ignition system that uses a one coil per pair of sparkplugs, which are connected in series through the coil. Besides being able to create one or two, selectable on-the-fly ignition maps, distributorless ignition systems allow a hotter spark because the ignition module has more time to keep a coil saturated for only two cylinders instead of 4, 6, or 8. This allows for higher maximum engine speeds the GM 4-pin HEI module. The two sparkplugs attached to each coil are 360° apart in the 4-stroke cycle. The cylinder on the compression stroke (event) automatically gets the hotter spark because the compressed fuel mixture has a higher voltage requirement than the exhaust stroke (waste) because the exhaust stroke's lower cylinder pressure and presence of ionized gases. In addition, because the sparkplugs are connected in series, the event sparkplug has the correct negative polarity while the waste sparkplug has the opposite positive polarity.
The hardest part of converting to the Ford EDIS is the addition of a 36-1 tooth trigger wheel on the crankshaft and the crank position sensor (Variable Reluctor pickup) to a suitable location on the engine. While the EDIS module and coil pack(s) can be mounted in any convenient area on or near the engine, the MegaJolt controller should ideally be mounted inside the vehicle's cockpit. This will necessitate drilling two holes: MegaJolt wiring harness & vacuum hose.
A member of the Slant Six Forum successfully used a MegaJolt ignition on his mono-fuel propane 1981 Dodge W150 pickup truck. See Propane Truck Update.
Tom Jennings has an excellent write-up about converting his Rambler Roadster (started off as 1961 AMC Rambler American 330) with a 195 cid inline 6-cylinder engine from distributor ignition to MegaJolt Lite Junior (a early version of the MegaJolt system). See Rambler 195.6 ignition.