I really wanted to make a few corrections, but this time I couldn't
. I would like to know the absolute reason why CDI is not used in a COP system anymore (other than Saabs older system). The slew rate thing has me confused. More capacitors? Doesn't make sense to me either. Perhaps more detail would help. I can say that after re-comissioning my wife's Honda Fit as we are coming out of Covid that it fired right up on the first compression like a CDI. That engine behaves like a CDI is installed but I'm pretty sure it's inductive from what I've read. Never a misfire or a stumble. Compare that to my coil near plug Chev truck that will start to misfire if idled too long (brings in a misfire code too). Fred
Quote:
Originally Posted by M&W Ignitions
Let us start out by stating cdi ignition is not for every application or for every person. Both inductive ignition and cdi ignition have their purpose and you can not state without qualification one is better than the other. Also remember we are a performace oriented company therefore do not get involved in unmodified factory vehicles.
Huh! Dont remember the last time we measured a COP style coil which has more inductance than an external coil, generally they tend to have less inductance due to restricted room for windings and little to no room for the magnetic core.
Here you are getting back into the old myth about longer arc duration being more optimal which has been proven false in many scientific papers. As per an earlier message the ability to ignite fuel is 'EI' Energy multiplied by Time. If you lack one you need to make up with a lot of the other. Multi discharge is also useless except in very limited circumstances as the crank has moved too far between sparks at anything much above idle. Multi dischage is used by both cdi and factory inductive ignition to help solve cold start emission issues on some modern engines.
Not sure where you are coming from here, that does not make any technical sense to us what so ever.
CDI ignition can be ready to fire the next spark in less than one third the time of the fastest inductive ignition system and is superior in dealing with agressive timing changes and firing interruptions than inductive ignition. CDI ignition is edge triggered and automatically recharges for the next event after firing unlike inductive ignition which requires a precisely positioned leading dwell period to prepare for the next firing event.
|