Frequently Asked Questions - FAQs
Q: What is the reliability of your Electronics Module and Optical Trigger?
A: We have sold a total of 1428 Crane/FAST XR700 modules and 1390 Optical Triggers since 1993, the vast majority as part of a complete kit. During that time, we sent out 18 Modules and 11 Optical Triggers to customers who claimed that they had a Module or Optical Trigger failure under warranty. All but 4 of those in both cases were pre-Ballast Resistor implementation so we are not convinced that all of the failures were really of the Module or Optical Trigger. Of course, what we do not know is how many customers had a failure and we never heard about it. If you do the math with the "failures" that we know about, there is a 1.26% failure rate for the Modules and a .79% failure rate for the Optical Triggers. I do not know how that compares to other components in the electronic world. Considering all of the variables on individual boats including key left on, lightning strike, system voltage, condition of connections, etc. we consider this to be an acceptable rate and it should only get better with the XR3000.
Q: Why all of a sudden are you worried about the Dwell Angle on Electronic Ignition?
A: That is a good question. We have known for years that the Indigo Electronics' Ignition (Crane/FAST XR700 Module) as well as the Pertronix Ignitor and standard points systems had a fixed Dwell angle although all three are most likely different. All of these systems produce a good spark under all operating speeds of the Atomic 4 but at the low end of the range, coil heating and failures has been a nagging problem due mainly to the large (long time with current flowing to coil) dwell angle. The coil heating symptom has been traditionally addressed through the addition of a Ballast Resistor. While this helped to keep the heating under control, there was obviously some deterioration of the spark quality. Until I came to fully understand and appreciate the capabilities of the Crane/FAST XR3000 module, I did not realize that you could have a variable dwell system and its benefits and totally eliminate the heating and spark deterioration issues.
Q: I don't understand something. If the dwell angle is fixed, what difference does it make what speed the engine is running?
A: It is a little confusing. A 4 cylinder distributor has four 90 degree quadrants as you look down on the cam (or shutter wheel). Each of these quadrants represents the angle over which a full ignition spark cycle occurs. Over the course of one rotation of the distributor shaft, each of the 4 cylinders gets a spark at just the right time to make the cylinder fire. During each 90 degree quadrant, a portion of the time there is current flowing to the coil and the angle over which that occurs is called the Dwell Angle. While that angle may remain constant, the time necessary for the distributor shaft to rotate through one Dwell Angle period gets shorter as the speed of the engine (and distributor shaft) increases. So as the time gets shorter, the length of time that current is flowing into the coil gets shorter. In order to be assured that the coil gets current for a sufficient length of time at maximum engine RPM, the dwell angle in a fixed dwell angle systems has to be large enough to always generate a good spark.
Q: What is the big deal about Current Limiting? I thought the amount of current was determined by the primary resistance of the coil and any ballast resistor.
A: You are correct. But would it not be ideal to have a coil with very low internal resistance, such as the FAST PS60, which will "saturate" more quickly and thus be perfect for high RPM applications. Having a current limiting function would allow that same coil to run well at all speeds without excessive heating of the coil by limiting the amount of energy going into the coil at lower speeds. In the case of the Atomic 4, that lower RPM range is where it typically operates so the PS60 can generate a great spark and still not overheat. The other very special feature of the Current Limiting function is that when the engine is not running yet the ignition switch is on, the Module stops the flow of current to the coil and thus prevents coils and modules from overheating and failing. We have chosen not to supply the PS60 coil with our kit as it is "overkill" for our low RPM Atomic 4. It would work very well if one to to install one.
Q: Can I easily upgrade my Indigo Electronics Electronic Ignition to take advantage of this new Module?
A: Absolutely! For the best possible spark, such an upgrade would require a new XR3000 Module and a matching PS60 coil. The actual change out simply involves removing and unhooking the existing module, remove the existing coil (and ballast resistor if one is present) and then installing the new coil and module with the wires and Molex connector all landing in the same relative positions. The wires are all color coded the same and the Molex plug is the same. The old module and coil can then be retained as a backup.
Q: My current coil is very new. Do I have to install a new coil when installing an XR3000 Module?
A: No, not necessarily. Through our own testing, most any coil will produce an acceptable spark and will not overheat. Additionally, other coils will not cause any harm to the XR3000 Module. The only downside to using a coil other than the low primary resistance PS20 is that the quality of the spark will not be as good. Will it be OK? Probably.If not, you can get the PS20 later.