Dual Fire CDI Manualf

8/11/2019 Dual Fire CDI Manualf

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Dual Fire

apacitor Discharge

Ignition


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Dual Fire CDI Instruction Manual

VERSION 1.0

Warning

Please ensure all power supplies are disconnected beforecommencing work.

This product produces high voltages. Careless use of this

product can cause harmful and fatal injury to humans.

DO NOT handle the red/white or red/yellow wires if the unit isconnected to power.

Incorrect set-up of this product can also lead to engine andproduct damage. Any damage caused due to incorrect set-upwill not be regarded as repairable under warranty.

Any unused wires must be insulated to prevent them fromshort-circuiting.

The power supply to this CDI must be fused with a fuse ratednot more than 20 amp.

Failure to follow all the warnings and instructions in thismanual may lead to product and engine damage and will alsovoid your warranty.


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LIMITED WARRANTY

EMS Computers Pty Ltd warrants the Dual Fire Capacitor Discharge system to befree from defects in material or workmanship for a period of 90 days from the date ofpurchase. Proof of purchase must be provided indicating that the product is within thewarranty period in order to receive warranty service. Removing the serial numberaffixed to the product will void any warranty.

If the Dual Fire Capacitor Discharge system is found to be defective within the rulesmentioned above it will be replaced or repaired at no extra charge this constitutes thesole liability of EMS Computers.

To the extent permitted by law, the foregoing is exclusive and in lieu of all otherwarranties or representations, either expressed or implied, including any impliedwarranty of merchantability or fitness. In no event shall EMS Computers, be liable forspecial or consequential damages.


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CONTENTS

Installation________________________________________________________________ 5

Connecting to Power _____________________________________________________ 5

Mounting_______________________________________________________________ 5

Ignition Leads and Sparkplugs _____________________________________________ 5

How to wire the input channels _______________________________________________ 6

How to wire the output channels ______________________________________________ 6

How to fire 2 channels together _______________________________________________ 7

How to wire the output channels for a rotary_____________________________________ 7

How to discharge 2 capacitors into one coil______________________________________ 7

Overheat protection _________________________________________________________ 7

Tacho output (brown/blue wire) _______________________________________________ 7

Operation modes ___________________________________________________________ 8

Rotary Mode (brown/yellow wire) __________________________________________ 8

Trigger Edge (brown/white wire) ___________________________________________ 8

Power Select (brown/pink wire) ____________________________________________ 8

Mode Select (brown wire) _________________________________________________ 8

Specifications______________________________________________________________ 9

Power Specifications Table ________________________________________________ 9

EMS Computers Dual Fire Pin Description_____________________________________ 10

Drawings ________________________________________________________________ 11

Socket view ____________________________________________________________ 11

4 cylinder example ______________________________________________________ 12



Rotary 3 coil example____________________________________________________ 15

Rotary 4 coil example____________________________________________________ 16


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Installation

Connecting to Power

The Dual Fire CDI has 2 red power wires and 2 black ground wires. These wires arejoined together internally and should also be joined together at termination. Thereason for using dual wires is to ensure maximum current flow. However, the amountof current draw is proportional to the number of cylinders and maximum RPM.Therefore, it may not be necessary to use dual wires if you have a 4 cylinder and notrunning the CDI in drag racing mode.

As a safety feature the Dual Fire CDI does not keep power onto the positive side ofthe coils if the engine is not running. The system will charge the capacitors on initialpower-up. If the engine is not started immediately the capacitors are dischargedagain. Once the system detects a trigger signal on any input channel it willimmediately charge the capacitors and fire the next output channel in sequence.

Mounting

Do not mount the unit where it will be exposed to water or excessive moisture.Select a location away from excessive heat and in a location that does not obstructair flow around the CDI.Use soft rubber mounts if the CDI will be subjected to strong vibration or the vehicleis has stiff suspension.

Ignition Leads and Sparkplugs

Do not use metal wire ignition leads because these will cause electrical interferencethat may effect the operation of the CDI or other electronic devices in the vehicle.

Do not use carbon suppressed ignition leads because the carbon core is NOTcapable of conducting the high energy levels of the CDI. Try to use ignition leads witha spiral wound inductively suppressed metal core.

Not all brands of carbon resistor spark plugs are able to stand the high-energy outputof a CDI system. NGK Q series and Champion Z series sparkplugs are specificallymade for high-energy applications.

IGNITION COILS AND THE CDI SYSTEM MAY BE DAMAGED INTERNALLY IF

FIRED WITHOUT A HIGH VOLTAGE RETURN PATH. YOU MUST ENSURE THATTHE SPARKPLUGS ARE GROUNDED BEFORE FIRING.


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How to wire the input channels

The EMS Dual Fire CDI is essentially 2 CDI systems in one. The odd numberedchannels use one discharge capacitor and the even numbered channels use another.In order to get the maximum benefit from the EMS Dual fire system you must wire the

input and output channels in an odd-even sequence. To achieve this, connect thefirst cylinder to fire to channel 1, the second cylinder to fire to channel 2, the third tofire to channel 3 and so on.

EG: If the firing order is 1,5,3,6,2,4 then connect the ECU ignition outputs to the CDIinput channels according to the table below.

Cylinder FiringOrder from ECU

CDI Input Channel Wire Colour

1 1 Pink

5 2 Orange

3 3 Grey

6 4 Yellow2 5 White

4 6 Blue

How to wire the output channels

This also applies to the CDI output channels. The CDI channel outputs must beconnected to the negative side of each coil. The positive side of the coils share twocommon voltage output banks, one for odd channels and one for even channels. Thered/white wires must be connected to the positive side of the coils for all odd

numbered channel outputs and the red/yellow wires must be connected to thepositive side of the coils for each even numbered channel outputs. The red/whitewires are connected together internally and the red/yellow wires are also connectedtogether internally.

EG: If the CDI input channels are connected as per the example above then connectthe CDI output channels according to the table below.

Cylinder Number CDI Output Channelfor negative side ofcoil.

CDI Output for Positive side of coil.

1 1 Pink/Black Red/White

5 2 Orange/Black Red/Yellow3 3 Grey/Black Red/White

6 4 Yellow/Black Red/Yellow

2 5 White/Black Red/White

4 6 Blue/Black Red/Yellow


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Operation modes

The Dual Fire CDI system can be programmed to operate in different modes byeither connecting the relevant wire to ground or leaving it unconnected.

Rotary Mode (brown/yellow wire)

Leaving this wire unconnected will put the CDI into piston engine mode. Connecting itto ground will put the CDI into rotary engine mode.

Rotary engines have a leading and trailing sparkplug for each rotor. These can befired simultaneously or the trailing just after the leading plug. For this reason youmust connect the trailing plugs to an even numbered channel and the leading to anodd numbered channel. The system must also charge the discharge capacitors in adifferent manner to piston engines.

Trigger Edge (brown/white wire)

Leaving this wire unconnected will cause the CDI to fire each output on a falling inputsignal. Connecting it to ground will cause the CDI to fire each output channel on arising input signal. All CDI systems have a delay time between the input channelsignal and the output channel signal. This is mainly caused by the noise filteringcircuit for each input. The Dual Fire CDI has a 28 microsecond delay for rising edgetriggering and a 68 microsecond delay for falling edge trigger inputs. Most high-endafter market ECUs such as EMS Motorsport ECUs have an ignition delaycompensation adjustment that can be set to cancel this delay.

IT IS VERY IMPORTANT TO SET THE TRIGGER EDGE ON THE CDI SYSTEM TO

MATCH THE ECU SETTING. FAILING TO DO THIS MAY DAMAGE THE ENGINE.

Power Select (brown/pink wire)

Leaving this wire unconnected will cause the CDI to operate in low power mode.Connecting it to ground will cause the CDI to switch to high power. By connecting thiswire to the auxiliary output of an ECU you can program it to switch the CDI betweenhigh and low power automatically in real time as needed.IE: Switch to high power mode when the engine is under heavy load.The power specifications table shows the power output for different mode and powersettings

Mode Select (brown wire)

Leaving this wire unconnected will cause the CDI to operate in circuit racing mode.Connecting it to ground will cause the CDI it to operate in drag racing mode.

In drag racing mode the CDI will deliver up to 570 volts to the coil. This can only besustained continuously for about 3 minutes at 714 hertz before the CDI starts to cutback power to prevent over heating. This gives plenty of time to finish the race.In circuit racing where the engine is running at high RPM for extended periods of timethis wire must be left unconnected. In this configuration the CDI is able do deliver upto 470 volts for very long periods of time at 714 hertz before its temperature becomes

too high.


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Specifications

Maximum operating frequency: 714 hertz.Delay on rising trigger edge: 28 microseconds.Delay on falling trigger edge: 68 microseconds.

Power Specifications Table

Separated Banks Bridged Banks

Circuit Mode Voltage Current Mili Joules Voltage Current Mili Joules

Low Power 370 5.1 68 280 5.8 78

High Power 470 8.7 110 370 10.6 136

Drag Mode

Low Power 470 8.7 110 370 10.6 136

High Power 570 11.3 162 400 15.6 160

The following output power and voltages are achieved with the battery voltage held at13.8 Volts


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EMS Computers Dual Fire Pin Description

1 Ground Black Ground

2 Ground Black Ground

3 Input 8 (8 Channel only) Violet Trigger signal

4 Input 6 (6 & 8 Channel only) Blue Trigger signal5 Input 4 Yellow Trigger signal

6 Input 2 Orange Trigger signal

7 Input 7 (8 Channel only) Green Trigger signal

8 Input 5 (6 & 8 Channel only) White Trigger signal

9 Input 3 Grey Trigger signal

10 Input 1 Pink Trigger signal

11 12 V Power Red Ignition 12 Volts

12 12 V Power Red Ignition 12 Volts

13 Coil Output 1 Pink/Black Neg. Coil

14

1516 Rotary Mode Brown/Yellow Ground this wire for

Rotary mode

17 Trigg Edge Select (Rise/Fall) Brown/White Ground this wire for risingtrigger. edge.

18 Power Select (High/Low) Brown/Pink Ground this wire for highpower. Can be connectedto ECU Aux output

19 Tacho Output Brown/Blue Square wave output

20

21 Mode Select (Drag/Circuit) Brown Ground this wire for dragmode

22

23

24 Output 8 (8 Channel only) Violet/Black Neg. Coil

25 Output 3 Grey/Black Neg. Coil

26 Output 5 (6 & 8 Channel only) White/Black Neg. Coil

27 Output 7 (8 Channel only) Green/Black Neg. Coil

28 Coil + for odd outputs Red/White Pos. coil for channels1,3,5,7

29 Coil + for odd outputs Red/White Pos. coil for channels1,3,5,7

30

3132 Coil + for even outputs Red/Yellow Pos. coil for channels

2,4,6,8

33 Coil + for even outputs Red/Yellow Pos. coil for channels2,4,6,8

34 Output 2 Orange/Black Neg. Coil

35 Output 4 Yellow/Black Neg. Coil

36 Output 6 (6 & 8 Channel only) Blue/Black Neg. Coil


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Drawings

Socket view

Socket is viewed from the back.


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4 cylinder example


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6 cylinder example


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8 cylinder example


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Rotary 3 coil example


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Rotary 4 coil example

Dual Fire CDI Manualf

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