Spark plugs
- Thread starter ryankesterholt
- Start date
Well, that article almost makes our discussion moot. If I understand correctly any changes to our motors, even a Stage 1, messes with the ion sensing?
Welllllllll....the stage 1 only adds more fuel and air basically but really does nothing to the resistance in the secondary ignition system.
Hoople
Account Removed
When I took a Brand new HD 6R12 spark plug and chilled it in a refrigerator I measured the resistance. Just under 35K when @ 35 degrees F. Began to warm it up with a heat gun and the resistance fell and fell and fell until it settled at about 1K (temp was at least a few hundred degrees). I have experience with temperature coefficient resistors but this is a little extreme.
So after taking a HD 6R12 and heating the electrical connection end with a heat gun it will unscrew out of the porcelain. Turning the plug upside down and tapping will result in the resistor and pressure spring falling right out. After taking a look at how they are made, it is no wonder there is no consistency from plug to plug..
So far everything seems to indicate the resistance of the plug is meaningless. 34K to 1K with everything in between just does not make any sense to me. If temperature compensation was that important, it would be in the Coil module and not in the plug. So at this point I would say that plug resistance is not something to be concerned with. That is to say as long as it is somewhere between 30K and 5K I don't think it will affect the Ion sensor operation.. (just my opinion at this point) Hopefully Delphi can clue us in with more detail.
So after taking a HD 6R12 and heating the electrical connection end with a heat gun it will unscrew out of the porcelain. Turning the plug upside down and tapping will result in the resistor and pressure spring falling right out. After taking a look at how they are made, it is no wonder there is no consistency from plug to plug..
So far everything seems to indicate the resistance of the plug is meaningless. 34K to 1K with everything in between just does not make any sense to me. If temperature compensation was that important, it would be in the Coil module and not in the plug. So at this point I would say that plug resistance is not something to be concerned with. That is to say as long as it is somewhere between 30K and 5K I don't think it will affect the Ion sensor operation.. (just my opinion at this point) Hopefully Delphi can clue us in with more detail.
Oh fine, now you tell me. Just bought the HD plugs to test, $8.
Anyway the readings were 19.5K and 24.5K resistance. I don't have any conclusions other than that the HD plugs seem to be the most inconsistent when new. BUT, all my lightly used HD plugs consistently read about the same. Be very interested to see what Delphi says. Hope they come back with a resistance range that they recommend.
I think I'll have a cocktail.
This is the part of the article I was referring to. It may even make your point.
It is a very good system and very reliable with one HUGE exception. Detection is dependent on the values calibrated in the software that represent knock, and are based on a stock engine ( or a known modified engine such as the STAGE I,II etc.) with a GIVEN set of Production intent parts.ie , Spark plugs, wires, and even compression ratio can and does change the resistance at the coil. So once folks start changing wires, Plugs ( to non-factory specs) and modifying the engine cams, compression ratio etc,( and even expected A/F ratios, and therefore combustion temperature) the values derived form a production engine are no longer valid and may cause the software to "determine" that knock is present when it's not or fail to detect knock when it is.
It would make more sense to me if the software read "anomalies" is the resistance pattern it senses from the circut. For example, if the resistance slowly climbed from say 20k to 30k or reduced from 40k to 5k as the engine warmed it would be a gradual climb or drop, but if the resistance spiked from 20k to 60k in mere milliseconds the software would react to a possible detonation condition.
IMHO that would make for a more lenient system with manufacturing variances in things like plugs, wires, etc..
This is just a hypothesis, as I really know nothing much about the new bikes and thier software.
IMHO that would make for a more lenient system with manufacturing variances in things like plugs, wires, etc..
This is just a hypothesis, as I really know nothing much about the new bikes and thier software.
Hoople
Account Removed
That does support the reason why you can "turn off" the Ion knock retard system using a SEST. When I first saw that, I wondered why anyone would WANT to turn off knock retard. Well that is the reason. Radical engine modifications to compression ratio or types of fuels would certainly require a different software trigger point. My guess would be for those of you who have made dramatic changes to the engine, to either turn off the feature or deep six the Ion coil pack.
Steve... Sorry about the plugs. R&D does not come cheap!
