Spark Plugs
#11
05-26-2023, 11:55 AM
Seasoned HDF Member
This topic comes up a lot. I really like and use NGK plugs, and I installed a set of NGK iridiums in my 16 FXDB, only to have the EMC pull ignition timing—-what da….. so I tried NGK regular ones , same thing happened. A couple of guys on this forum said I was full of crap. Well they probably have a different set up, don’t know ( or care). The Ion- sense these bikes are equipped with do not like any thing but OEM. You can ohm out the OEM Champions and then others only to find extreme differences ( if that means anything or not). What I do know is that the OEM Champions work right , don’t retard the timing like the NGKs did and runs just fine.
Not a Twin Can with Ion sensing ....
Stock ignition on a stock Evo will still be the OEM 5r6a or an equivalent copper plug...
#12
05-27-2023, 09:34 PM
Road Master
When I had my EVO I played with Splitfires but couldn't detect any difference from stock, so money not well spent. I did get a set of indexing washers and always went to the trouble of getting the plug gaps pointed to the incoming charge. The motor seemed a bit smoother and a bit more powerful but could have been the placebo effect.
#13
05-29-2023, 01:39 PM
Stellar HDF Member
Hopefully some info that will be taken in the spirit in which it is intended…
The purpose of a sparkplug is to spark to light of the charge in the combustion chamber…that’s it! There’s nothing more…just a spark.
Low compression engines need less intense spark while high compression need a stronger spark…like the stock sparkplug!
We’ve done many back to back sparkplug comparisons over the years only to be reminded to save money and use stock plugs. The exception is TwinCam timing retard control is controlled by an “ion sensing” system that determines combustion quality and adjusts timing advance based on the measured resistance compared to a lookup table in the ECM so specific spark plugs are required to present the expected, accurate readings the system was designed for. When using non-stock plugs there is a good chance the timing retard control will be taking out timing when not needed or desired, reducing performance from retarded timing.
Thru our own research the NGK 4179 sparkplug seems to work as close to a stock plugs as anything we’ve found. It also has a solid top which eliminates the chances of elevated resistance causing false knock retarding by the system.
Not sure how the new Knock Sensors (actual hardware bolted to the engine) used on the M8s will sort out and if we will be able to adjust the sensitivity levels.
Bob
The purpose of a sparkplug is to spark to light of the charge in the combustion chamber…that’s it! There’s nothing more…just a spark.
Low compression engines need less intense spark while high compression need a stronger spark…like the stock sparkplug!
We’ve done many back to back sparkplug comparisons over the years only to be reminded to save money and use stock plugs. The exception is TwinCam timing retard control is controlled by an “ion sensing” system that determines combustion quality and adjusts timing advance based on the measured resistance compared to a lookup table in the ECM so specific spark plugs are required to present the expected, accurate readings the system was designed for. When using non-stock plugs there is a good chance the timing retard control will be taking out timing when not needed or desired, reducing performance from retarded timing.
Thru our own research the NGK 4179 sparkplug seems to work as close to a stock plugs as anything we’ve found. It also has a solid top which eliminates the chances of elevated resistance causing false knock retarding by the system.
Not sure how the new Knock Sensors (actual hardware bolted to the engine) used on the M8s will sort out and if we will be able to adjust the sensitivity levels.
Bob
#14
05-29-2023, 02:27 PM
Seasoned HDF Member
Hopefully some info that will be taken in the spirit in which it is intended…
The purpose of a sparkplug is to spark to light of the charge in the combustion chamber…that’s it! There’s nothing more…just a spark.
Low compression engines need less intense spark while high compression need a stronger spark…like the stock sparkplug!
We’ve done many back to back sparkplug comparisons over the years only to be reminded to save money and use stock plugs. The exception is TwinCam timing retard control is controlled by an “ion sensing” system that determines combustion quality and adjusts timing advance based on the measured resistance compared to a lookup table in the ECM so specific spark plugs are required to present the expected, accurate readings the system was designed for. When using non-stock plugs there is a good chance the timing retard control will be taking out timing when not needed or desired, reducing performance from retarded timing.
Thru our own research the NGK 4179 sparkplug seems to work as close to a stock plugs as anything we’ve found. It also has a solid top which eliminates the chances of elevated resistance causing false knock retarding by the system.
Not sure how the new Knock Sensors (actual hardware bolted to the engine) used on the M8s will sort out and if we will be able to adjust the sensitivity levels.
Bob
The purpose of a sparkplug is to spark to light of the charge in the combustion chamber…that’s it! There’s nothing more…just a spark.
Low compression engines need less intense spark while high compression need a stronger spark…like the stock sparkplug!
We’ve done many back to back sparkplug comparisons over the years only to be reminded to save money and use stock plugs. The exception is TwinCam timing retard control is controlled by an “ion sensing” system that determines combustion quality and adjusts timing advance based on the measured resistance compared to a lookup table in the ECM so specific spark plugs are required to present the expected, accurate readings the system was designed for. When using non-stock plugs there is a good chance the timing retard control will be taking out timing when not needed or desired, reducing performance from retarded timing.
Thru our own research the NGK 4179 sparkplug seems to work as close to a stock plugs as anything we’ve found. It also has a solid top which eliminates the chances of elevated resistance causing false knock retarding by the system.
Not sure how the new Knock Sensors (actual hardware bolted to the engine) used on the M8s will sort out and if we will be able to adjust the sensitivity levels.
Bob
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