Electromotive xdi, Installation Manual & Users Manual

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XDI Manual Version 1.8 Page 8

2017 Electromotive, Inc.
a high compression engine, the voltage at the plug will be inherently higher (since there is more load). The
detriment is that spark plugs and wires are only rated to a certain voltage (30-40,000 volts is typical), and can
begin to “blow out” at around 40,000 volts. If that voltage is exceeded by a large amount for a long enough
length of time, the spark plugs will either blow out, break down or arc to somewhere other than the electrode
(often through the insulator directly to the engine block).
The solution is to run smaller plug gaps on high-compression engines. This is perfectly acceptable with
our ignition charging method, since the high load of the cylinder pressure will allow the voltage to be quite high
at the electrode, but the small gap will keep the plug from seeing an over-voltage situation. Use the
recommendations below as a guideline for spark plug gaps:

Stock Street Engine
0.045”-0.060” (1.1mm-1.5mm)

High Performance Street
0.030”-0.035” (.75mm-.9mm)

Alcohol High Compression
0.025” (0.65mm)

High Power 75 -115 HP per Cylinder
0.025” (0.65mm)

Over 115 HP per Cylinder
0.022” (0.55mm)

Over 12:1 CR or Over 14psi Boost
0.022” (0.55mm)
Use of resistor plugs is highly recommended for optimum noise suppression. If using anything other
than a resistor spark plug wire, a resistor plug MUST be used. The bottom line is this: the XDI system uses an
inductive (long duration charge at battery voltage) charging method for the coils, which is completely different
than the capacitive (short duration charge at higher-than-battery voltage) charging method used by several other
aftermarket manufacturers. What may work well for these systems may not work well for ours. Following our
recommendations about spark plug and wire selections will yield excellent results.
2.0 Engine Configuration Guide
The XDI is a completely configurable ignition system. The same XDI can be used for all the engine
configurations listed below.

1 Cylinder

2 Cylinder 2 Stroke Twin-Fire

3 Cylinder 2 Stroke

4 Cylinder - 2 Stroke

- 4 Stroke

- Dual Plug

- Odd-Fire

6 Cylinder - Even-Fire

- Odd-Fire

- Dual Plug

8 Cylinder

- also with a 4 Cylinder Tachometer Output

12 Cylinder

- also with a 6 Cylinder Tachometer Output

Rotary – 1,2 or 3 Rotor
To select between various engine configurations, 8-dip switches must be adjusted. An Electromotive
Value Added Dealer typically performs the configuration procedure. This manual provides an overview of the
configuration settings, if the switches need to be checked or the configuration changes.