BMW OMEGA Electronic Ignition FAQ

General Questions

  1. I have a '79 R65 with points in a beancan.
    R65 works with default curve "4".
  2. Does the small rectagular box contain the advance retard software? How do you program different advance curves?
    The small rectangular silver box (with the OMEGA sign) contains the amplifier/booster only. There is a micro-switch on the red sensorboard to set the appropriate advance curve.

  3. Did you retain stock 6v coils for use with this system, on the 100/7?
    I am running stock coils on the /5 and Bosch Blue Coils on the '79 /7.
  4. I get conflicting information on whether a 0k, 1k or 5k plug cap should be used with the OMEGA Electronic Ignition.
    It will run with any combination of HT lead, spark plug and caps, with or without resistance. See also this discussion on Boxerworks:http://www.boxerworks.com/phorum/read.php?f=1&i=185703&t=185703
  5. Is it necessary to replace the condenser as well as make the single wire swap to restore the original points system ignition?
    I always recommend that before you switch to the OMEGA to have a working points ignition, tuned up and ready to go. Then you install the OMEGA and just in case, it fails some day you're sure your points system will work. The condenser can stay in as can be seen on the picture below. It is NOT part of the OMEGA setup, it belongs to the points and prevents excessive arcing.
    click on photos for a larger view
  6. How does one determine the proper curve choice?
    Simply Try and Error: start with default curve "4" and work your way up or down.
  7. The bike currently has the original coils in it. I don't know if they are functional or not. Do you have any recommendations for replacements?
    I used Bosch Blue coils as have many others. Stock BMW is fine as well. Some also used the Honda Goldwing coils (see Coil section further below)
  8. I am interested to install one on my 1992 R100R, but it does not seem to be compatible with my model BMW. Is this correct, if so why would it not be compatible?
    Simple answer is: it is compatible. The R100R is not specifically mentioned, it falls under Type V - BMW R45-100 .. from 1981
  9. Looking at the adjustable pot on the printed circuit board I see, A,C,E,0,2,4,6,8. so how does this give you 9+1 (zero) advance positions? Ahhh! You also count the dots between each letter /number, eh? Start at 0(zero) rather than A. The instructions mention (9+1 choices, the online site mentions up to 15 pre-programmed choices.
    There are 15 advance curves from 0 ... 9, A=10, B=11 ... F=15. Yes, I changed that on the website (but forgot the 9+1, has been changed now), the written German instructions are old and have not been updated, the online English Instructions are up-to-date.
  10. What OMEGA would fit my R90S?
    You need the OMEGA Type W for your R90S.
  11. I couldn't get the circuit board and the rotor timing disk to make nice concentric circles. It is free on the bottom, but just, I ran a piece of paper all around. Does it matter?
    As long as the aluminum disc does not touch the red printed circuit board, there is no problem.
  12. During installation the nut for the brush holder is replaced by a brass coupler. A set screw is threaded into the coupler to hold the red ignition trigger. The original nut together with a wave washer (provided) is then reused. I found this nut difficult to tightened since it was recessed into the trigger unit. I used a set of needle nosed pliers, not the best tool for the job.
    The height tolerances at this particular spot are very tight. Some models are tighter than others. The solution provided is taken into account the worst case. In some case a standard (metric) M5 screw with slotted head will work. We realize that there is no standard tool available and will think of another solution.
  13. Why is there a microchip on the underside of the red sensor board?
    Beginning 2007, OMEGA has made the advance curve microchip easily accessible for future applications such as the "OMEGA High Performance Chip".
  14. Dwell angle: What dwell angle does the OMEGA employ? Is the angle variable or is it fixed in a time frame instead ?
    The dwell is variable from 9ms to 2ms to achieve charging to approx. 60% of the maximum possible charge (magnetic energy) of the coil.
  15. Amplifier rating: you rated the amplifiers in terms of coil resistances. Lower resistances will draw higher current and is obviously an analogue but not an exact indication of amplifier rating. What are the nominal and peak current ratings that the amplifier can withstand at what temperature?
    • Type W – 14A continuous at 195F/90C, 45A peak with overcurrent protection
    • Type V – 24A continuous at 195F/90C, 55A peak with overcurrent protection
    • Supply voltage (overvoltage) protection is set at 18V
  16. Reverse Energy / Back-EMF considerations :
    • Max reverse energy 120-140MJ @ 4mH inductivity, included 5-10% reverse energy from spark plug
    • Integrated protection for full reverse energy caused by instant spark plug cut off (worse condition for reverse energy)

Dual Plugging

  1. Using two 6V dual coils in series: If two coils of low resistance and dual HV outputs were used in series (dual-plugged), it would total 1.2 ohms running off one channel.
    We are advising strongly against using two dual coils in series on one output! The two coils are generating twice the back-EMF of one coil at firing time that the amplifier must withstand. That phenomena is also related to the primary impedance of the coil and total magnetic charge.
    However (not supported and thus voiding the warranty):
    Since magnetic charge is a function of ampere-turns (inductance), the current level is an adjustable parameter that can be utilized to achieve a high energy system while still maintaining a low level of back EMF toward the amplifier. If a low impedance primary winding is used with high current capability, it is conceivable to apply two coils safely for dual plug use on one amplifier.
  2. Would this system accomodate dual plugs? Timing and resistance?
    There are two models available specifically designed for dual-plugged bikes.
  3. For a dual plug setup, normally we would start with static timing at TDC (top dead center). Is this the case with the OMEGA or should I use the 9 degree S mark?
    I confered with a customer using two of the Oilhead 4V coils for his dual-plugged R100R: he has experimented and ended up with 3deg before TDC for static timing. I guess that should be your starting point and you can go from there and try to find your "sweet spot".

Coils
Which coils can be used?

1969-1981 Standard Bosch 6V or Bosch Blue Coils
(use OMEGA Type W)
1.2 Ohm resistance (x 2), 54mm dia
Honda Goldwing Dual Coil pn #30500-422-003
(use OMEGA Type W)
~2.1 Ohm, 46mm dia (also a good alternative for dual-plugged bikes)
1981-1984 Standard Bosch 6V or Bosch Blue Coils
(use O MEGA Type V)
0.6-0.7Ohm resistance (x 2), 54mm dia
1985-on Bosch 12V Dual Coil
(use OMEGA Type V)
1.2 Ohm resistance (2 needed for dual plugging)
1993(or thereabouts)-on Bosch 12V Dual Coil
(use OMEGA Type V)
0.6 Ohm resistance (2 needed for dual plugging)

The significance of coils in an OMEGA Electronic Ignition Circuit

An ignition coil is an autotransformer with a high ratio (approx 100:1) of secondary to primary windings. It works as an inductor: when the primary winding is connected to 12V (the battery), it is "charged" and within a couple of seconds a magnetic field is built up as a result of the current. The strength od this field is proportional to the current. The maximum current is determined by battery voltage and contact resistance, thanks to Mr. Ohm.

(1) I = U / R

Where I is Current, U is Voltage and R is Resistance.

This charging is not instantaneous and the time largely depends on the windings' resistance and inductance (see also Figure 2 further below).

Since primary and secondary coil "share" some of the windings, a voltage of a couple of thousand volts is created at the output during "charging", not enough to create a spark though.
The way to put a long wire into a magnetic filed is to wind it into a coil and concentrate the magnetic field through the coil. So here you have it: your ignition coil.




Figure 1. Coil Schematics

A shorter wound wire is used to charge the coil via electromagnetism, and a long wire to create the 10,000s of Volts to get a spark. Here another physical law applies thanks to Mr. Faraday: If you place an inductor (a piece of wire) in a CHANGING magnetic field then a voltage will be produced, the longer the wire, the shorter the change the higher the voltage.
A contact breaker in form of points or electronics changes the field rapidly.

(2) V = L x dI

Where V is Voltage, L is Inductance and dI is the rate of change of the current.

The abrupt change in current will produce a very short, very voltage spike. The change of current is on the primary side as well, but is the secondarys side where 10,000s of volt are created. Again, less current is flowing on the primary side the higher the coil resistance on the primary side. "A" indicates opening the point/circuit, points close a "B", magnetic field is built up at "C".




Figure 2. Charge/Discharge Diagram

OMEGA Electronic Ignition Specifics:
The two available OMEGA Ignition models are Type W and Type V:
Type W is intended for the earlier points systems where coil resistance is in the order of 1.8Ohm to 5.0Ohm or higher: dual coils from Honda Goldwing or Dyna Dual Coil (green 3Ohm, grey 2.2Ohm or black 5Ohm) can be used with Type W Ignition
Type V is for high energy/low resistance coils with 0.5Ohm to 5.0Ohm or higher, used as an add-on or replacement in modern electronic ignitions such as Dyna and others or BMW's stock electronic ignition used from 1981 onwards: dual coils such as BMW 2V Dual, BMW 4V Dual, Dyna Dual (blue 0.7Ohm or brown 1.5Ohm), Andrews 6377B, Hot-Spark 2HS06HEC etc can be used with the Type V Ignition



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