se spark plugs

Discussion in 'Electrical' started by johndeeredr, Dec 19, 2011.

  1. johndeeredr

    johndeeredr Member

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    2008 fatboy with stage one kit installed and tfi. i also have the SE 10mm wires and i also installed se iridium gold spark plugs just to have the best of the best for my baby. was serching the forum and ran across threads saying that i have disabled the anti knock feature in my ignition system. is that true? i have noticed that maybe the engine has to turn over a little longer sometimes but runs great. should i change back to oem,s?
     
  2. glider

    glider Veteran Member

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    When a system is designed to work with certain parts so the secondary resistance can give you the ION sensing and you change parts of that system to other than stock, the ION sensing cannot work properly then.

    I wouldn't change parts just because I felt like it but would replace the parts with stock parts if the knock system is important to you. Remember that your ear cannot always hear knock in the engine as you ride.

    The stock plugs and wires are more than up to doing the job on a stock or stage 1 engine. It only comes into play with a higher output engine with increased compression etc.
     
  3. dbmg

    dbmg Experienced Member

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    My dealer always tries to sell me the SE plugs. I just use the OE type and change then out at 10k interval and never have had a problem....
     
  4. HarryB737

    HarryB737 Junior Member

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    I've had less problems out of stock plugs than other higher $ plugs & the engine runs Great.
     
  5. johndeeredr

    johndeeredr Member

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    just found the plugs that came with my bike and they are champion RA8HC. are those harley numbers? sounds automotive to me.

    did a little web search and found out this are plugs for this year and model, but will the anti knock part of the ignition system work?
     
    Last edited by a moderator: Dec 19, 2011
  6. glider

    glider Veteran Member

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    They are the Champion equivalent of the 6R12 from Harley. Champion makes both plugs and there isn't much of a difference in resistance between the two.

    Why not just get the 6R12 and be done with it?

    People spend much too much time trying to find a substitute IMO when the stock 6R12 are plentiful at any dealer and you know they would work with the ION system.

    You also can find a cross reference here too without going crazy...:s

    Harley Davidson Community
     
  7. johndeeredr

    johndeeredr Member

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    thanks for the info glider. thes came with the bike and have less than a thousand miles on them so i will put them back in. had no problems with the iridium plugs , but just wanna be sure that i dont hurt the engine in any way. thanks for all the input.:newsmile105:
     
  8. R_W_B

    R_W_B Senior Member

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    Could you possibly give me the link that said that. Is it saying the plugs alone causing the ION sensing issue, OR the combo of the plugs and wires ?

    I'm a bit skeptical on plugs or wires affecting the resistance enough at the very high voltage output of the secondary to matter much, but would like to educate myself on this. The way I've read this in the past, the compression ratio plays into the resistance more than the few inches of wires or plugs. I would think the ION data and the ECM would establish an analyzed base line rather than a set amount of resistance, but then I'm no expert.

    My personal opinion is that unless you have race setup, any "unbroken" plugs wires are fine. In the old days so you didn't have to hear the engine wind thru the gears in static on the car radio, they had graphite core wires. These were easily broken from mishandling and caused problems.

    Nowdays plugs and plug wires have come a long way since static interference also affects the ECM/PCMs as well as the radio. Nowadays many plugs themselves have semi-conductor improved resistors in them to hold down the RFI. As long as you have a good unbroken conductor over the few inches from the coil to the plug you are in good shape.
     
  9. glider

    glider Veteran Member

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    Harley Davidson Community
     
  10. R_W_B

    R_W_B Senior Member

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    Well I read that one, and the one by Hoople. Both were very interesting. I get the jest that biased dc voltage across the ionization is measured and sent back to the ECM for it to compare to calibration tables. As to it being measured "after" detonation I can only wonder, if that means after the ECM (or ignition module or pickup coil trigger) has told the coil (by cutting it's primary field causing collapse) to fire the plug OR it measures ionization during a period prior to firing the plug so as to actually tell if it's pre-ignition or ignition. That part escapes me as to how it can decipher pre-ignition ionization as opposed to ignition ionization. Albeit the term "after detonation" seems to imply the former. I understand I am told that ionization is affected by pre-ignition, I can only take it by faith that the effect is still showing up after plug firing, i.e. possibly more ionization registering than if no pre-ignition had occurred (?). That's getting a lot from those pre determined calibration tables.

    I emailed the plug manufactures and only 2 have replied thus far. It appears that pretty much "ALL" ECM/PCM engines now days must have "some" resistance built into the plug and/or wires or the interference will affect the ECM and cause poor idle and erratic running. Most of them say the resistance is about 1K ohms. I would guessitmate the voltage coming off the collapsing coil at trigger is somewhere around 120,000 volts, but that last figure is purely my own guess based on 12 volts times 1 to 10,000 primary to secondary ratio.

    I still don't really see how a spark plug could make all that much difference in the resultant voltage spike. Nor have they been proven to increase or decrease performance to any real degree. If some are saying it does, then far be from me to say they are wrong, I'm only saying I ain't convinced yet. However from what I have read I am pretty much convinced that other factors (that have been proven to affect performance more than plugs or wires) such as stage one AC, more air flow exhaust pipes and higher compression setups.

    So then it would appear that everyone that has a stage one (or stage 2) setup that does not have a "corrected" ion calibration table in the ECM is definitely not utilizing the ion data. Even if you have a tuner (regardless of it's sophistication) if it's pre-determined calibration tables have not been compenstated then (from what I've read) the ion data returned is useless.

    If I might say so, (which is a bit presumptious for an old redneck like me) I find it somewhat incredulous that such a system would be designed to base it's reactions on a pre-determined calibrations given the many tempature and atmospheric conditions that any given engine can be exposed to depending on it's location of operation environment. Notwithstanding that a large percentage of us have nulled that effect with many more items than spark plugs.

    I thank you for the information though, it was good reading.