Note: Megajolt/C is a canceled project and there are no plans, present or future, to complete it.

Introduction

The Megajolt/C is our next generation crank fired ignition system specially designed to work with the latest in ignition coil pack technologies. What sets Megajolt/C apart from other designs is the absence of built-in coil drivers: by moving these high-power drivers to external modules, we’ve been able to shrink the form factor while providing 8 flexible coil control channels, capable of a variety of ignition configurations:

• Crank-Fired Wasted Spark for 4,6,8 and 12 cylinders
• Crank-Fired Sequential ignition for 4, 6 and 8 cylinders

If your engine can drool

If you’re running distributor based ignition, especially old-style points,  you’ll treat your engine to the following benefits:

• Overall improvement in engine smoothness and drivability
• Stronger spark throughout the RPM Range, especially at higher RPMs. Stronger Spark = more efficient burn = more power.
• Improved idle stability
• Full tunability with up to a 16×16 ignition map
• No mechanical parts (rotor, cap) to wear out
• No plug wires to replace (if running coil-on-plug modules)

If you’re already running a Megajolt Lite Jr / Megajolt/E you will want to upgrade only if:

• You’re an early adopter and like playing with the latest tech
• Your engine’s redline capability is beyond EDIS capabilities (about 8000 RPMs for EDIS-4, 7300 RPMs for EDIS-6; 6300 RPM for EDIS-8)
• You need and/or have a burning desire for true sequential ignition

Finally, you’ll benefit from the features you’d come to expect from a modern piece of tech:

• Powerful 32 bit ARM processor
• USB connectivity
• Bluetooth expansion (details below)

It’s all in the Name

The C in Megajolt/C stands for ‘Coil On Plug’. Meaning, it’s designed to work with coil packs having built in drivers (aka ‘igniters’).  These coil packs first appeared on engines produced around year 2000, becoming commonplace on recent models. Often implemented as ‘coil on plug’ modules, such as the units found on the Toyota 1ZZ-FE engine (Corolla, MR2) , they also appear in the ‘coil near plug’ form-factor, as found on the GM LS1 engine, seen on the Chevy Camaro and Corvette.  European manufacturers such as BMW, Mercedes and Volvo have their own implementations as well.  With these modules becoming cheaply available in automotive wrecking yards and brand new from automotive parts suppliers, the time is ripe for an ignition controller designed to take advantage of this tech.

Crank-Fired and Cam Synchronized

To compliment the 8 coil driver outputs we included a dual VR sensor input- one for the crank and one for camshaft synchronization.  If both are used, Megajolt/C provides true sequential ignition for for 4,6 and 8 cylinder engines, benefiting high RPM applications.

Dwell is the period of time the coil pack ‘charges’  before the spark plug is fired. In order to produce optimal spark energy, sufficient dwell time is needed (approximately 3-4ms). Since available Dwell time is inversely proportional to engine RPM, having sufficient Dwell time at high RPMs is critical, as this is when the engine is producing maximum power!

The following table illustrates available dwell time across different ignition system technologies:

Type	How often does the coil fire?	5000 RPM	7500 RPM	10,000 RPM	15,000 RPM
Distributor	Every 180 degrees	6ms	4ms	3ms	2ms
Wasted Spark	Every 360 degrees	12ms	8ms	6ms	4ms
Sequential	Every 720 degrees	24ms	16ms	12ms	8ms
Max theoretical available dwell time per cylinder (4 cylinder application)

Note: The actual available Dwell Time is somewhat less due to processing overhead present in the Engine Management System.

As you can see, full sequential ignition is best suited for very high revving engines; For wasted spark, take comfort that this configuration is good to about 10K RPMs.

Bluetooth Integration

It kind of smacked me in the head when I was kneeling next to our Merkur XR4Ti at a race, frantically making an adjustment to the engine management system using my ‘compact’ laptop.  The screen was hard to see, I had no table to set it on and the cable was too short. As a result, I had to squat on the ground, laptop perched on the floor of the Merkur, and shield the screen with my hands while trying to use the touch pad and keyboard. Ridiculous!

In my annoyance I realized there was a much better way, using the incredibly capable Android device I had stuffed in my pocket. Of course! The system should’ve had Bluetooth embedded- with wireless integration to my smartphone. I could whip it out, make a few adjustments on the easy to hold, easy to see,  and easy to use form factor and off I would be.

Expanding on that- imagine the following capabilities with your smart phone or tablet:

• Full control over settings – ignition map, options, configurations- etc.
• Interactive gauges / dashboard. Put a suction cup mount on the windshield and gain an instant heads-up display!
• Datalogging and tuning to your heart’s content. No need for the hardware to have an SD card slot:  It’s all possible your smartphone / tablet.

Due to cost, we felt that bluetooth integration should be an option- so we’re including a header on-board to receive an add-on board with an embedded Bluetooth transceiver. Cool!

Inputs and Outputs

Aside from the minimum inputs for proper functionality, we’ve added some extra features to make a well rounded system.

Sensor Inputs

• On-board MAP sensor: The same on-board MAP sensor used in existing Megajolt variants is a proven, cost-effective solution compared to expensive OEM modules.
• Throttle Position Sensor (TPS): For measuring approximate engine load when it’s inconvenient / impossible to get a stable vacuum reading (e.g. using bike carbs)
• Temperature Input: A coolant temperature sensor input for correcting ignition advance during engine warm-up period.
• Aux input: An extra analog input for.. future expansion (e.g. work with an external knock sensing module)

Option Input

As with existing Megajolt variants, the Option input will be used to switch between ignition maps on the fly.

Programmable Output

One programmable output is provided to drive an accessory device, triggerable on RPM, load, or other sensor value (1A capable)

Shift Light

A programmable shift light output is provided, which can directly drive an LED or small indicator lamp (1A capable)

Tach Output

A 12V pulsed output is made available which can drive a variety of OEM and aftermarket tachometers

Bonafide Vaporware

As of this writing we’re fabbing out the Revision A PC board. What’s great is the form factor will fit the existing enclosure we use for the Megajolt/E.  Here’s an idea of what it will look like:

In a few weeks time we will have buildable-testable boards in-hand.  Keep an eye on our forums for the latest news!