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Spark plugs and Delphi's Ion Sensing Ignition System

14K views 16 replies 10 participants last post by  Jan-Dirk  
#1 ·
I talked to one of the engineer's that did quite a bit of the sparkplug and fuel testing on this system at Delphi. It will work equally as good with any sparkplug or gasoline. He said the only thing it didn't like was a fuel additive made by Gunk.
 
#2 ·
I talked to one of the engineer's that did quite a bit of the sparkplug and fuel testing on this system at Delphi. It will work equally as good with any sparkplug or gasoline. He said the only thing it didn't like was a fuel additive made by Gunk.
From my own personnel experience and from what I've read in technical white papers about the Delphi Ion Knock Sensing it does matter what spark plugs you use. While tuning my motor in the timing section of the map with NGK's which have a 3K resistance I could hear that the motor was knocking under load but the play back of the recording I took showed no signs of knock. I left the settings in the map the same and used the HD plugs which have a 22K resistance and took the bike out for another recording session. There was no knocking under load but there was a definite flat spot at certain RPM's. When I checked the recording right at those flat spots it showed the knock detection had kicked in and retarded the timing as I had pushed the timing too far advanced at those Rpm settings. The Delphi Ion Knock Sensing is specifically calibrated to work with the resistance of the HD plugs.
 
#4 ·
Please except my humble apology. I was just trying to pass on what I thought to be revelant information from an engineer that did development work on the system. I didn't realize the forum had a new self proclaimed ion sensing guru. I'll be sure and tell this guy he is full of shit the next time I talk to him. Keep buying those special Harley spark plugs. Peace Out
 
#8 ·
If you read the principals of how the system is designed to work it reads resistance during the burn. So if your plug has a different resistance base valve it changes the calibration of the system and the will not operate correctly
You can use any plug you like as long as it has the same base resistance value as factory plugs.
It's science but not rocket science gent's

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#10 ·
You guy's believe what you want. Harley would be all over the specific sparkplug thing. SV, I'm not trying to start a pissing contest with you. You jumped in my thread and you are entitled to your own opinion. If you want to believe that you know more about how the system works than the engineer's that developed it, than carry on. I'm going to see if I can find out how the system compensates for different sparkplug resistance. I work with high end knock sensing equipment everyday. I know how it works, but I couldn't even begin to guess what goes on in the black boxes.
 
#16 ·
Thank all you gentlemen for the data. I also changed my plugs to NGK and now have vibration. Since this is the only change I have done and there was no prior vibration it must be the plugs causing the problem. I will be going back to the HD plugs.
 
#17 ·
8 is too warm, I have used 9 for many years without any problems at all (before I did the turbo thing)
But anyhow, this really is no subject to get excited about. Use what you like just don't assume that what you experience is written in stone. Sometimes it#s better to ignore different opinions, believe me I must know :chainsaw: