Plug Gap

Discussion in '1996 - 2004 SN95 Mustang -General/Talk-' started by Paul1981610, Jul 25, 2014.


  1. Paul1981610

    Paul1981610 Member

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    01 gt Saleen series one with intercooler smaller pulley 24lb injectors. No boost gauge yet. Having rich issues at WOT. presuming blow out. I am gapped at .035. Should I go smaller gap
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  2. restomod66

    restomod66 Member

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    Supercharged applications require specific plugs with a different heat range (cooler) and tighter gaps. If my memory serves me correctly I ran NGK TR6's gapped @ .032 on my Supercharged 01 Cobra a number of years ago, it ran smooth as a stocker.
    Last edited: Jul 25, 2014
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  3. Gearbanger 101

    Gearbanger 101 Straight Outta Locash Super Mod

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    Had the same plugs and gap in my 4.6L Supercharged Cougar XR7. Made 10psi and ran like a clock.
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  4. Nightfire

    Nightfire Mustang Master

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    The greater the boost, the smaller the gap. Seeing that you are running a Saleen blower (probably the worst possible blower ever made), you are probably barely breaking 300rwhp. Your gap is not an issue. It is the tune that is running rich. Do you have a wideband?
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  5. Paul1981610

    Paul1981610 Member

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    Well I did t have this issue until I changed plugs. The tune never changed. And thanks for telling someone that their supercharger is terrible. I'm a low budget guy and proud I even have one. And no no gauges at this point
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  6. stangr5oh

    stangr5oh Active Member

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    I do not think he meant anything toward you when he announced his opinion toward the charger on your car. But if the tune has not changed, and as we spoke before about this in your other thread, I would change out those Bosch plugs. I am telling you from experience, they are garbage when it comes to our applications. As they mentioned above, go to another plug, NKG or Autolite. The gap is smaller when it comes to chargers. The gap on yours should be .032, over time it will expand to about .035.
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  7. Paul1981610

    Paul1981610 Member

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    I installed Autolite 103 last night gapped at .035 and it is way better but just not quote right. Still blowing at high boost. Going to regap again
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    Kilgore Trout likes this.
  8. stangr5oh

    stangr5oh Active Member

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    How long ago did you dump that SeaFoam in your tank? And are you still running on that same tank of fuel? I would tend to believe that if you are still on that same tank or next refill, you are seeing that the SeaFoam after effects of all the carbon blowout.
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  9. Paul1981610

    Paul1981610 Member

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    Prolly 6 tanks. I use 93 non ethonal
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  10. Paul1981610

    Paul1981610 Member

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    It's not just smoke blow out. It actually sputters or loads up at high boost. All the old plugs were sooty. Has to be spark blow out IMO. But that's why I'm here getting other opinions
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  11. stangr5oh

    stangr5oh Active Member

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    Well re-gap them to .032 and also make sure your COP boots are in good condition. After time and heat exchanges continually the COP boots get hard and cut or rip very easily. So when you re-gap the plugs, look closely to each boot and if any are hard and and you suspect a tear or crack rip whatever you want to call it, replace them. They are cheap at any auto store, and I experienced stumbling on my Mark VIII last year and I had 2 boots cracked causing the spark to arch off the block. After fixing them, it purred like a kitten.
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  12. Paul1981610

    Paul1981610 Member

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  13. Kilgore Trout

    Kilgore Trout Fried or Broiled ?

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    I would not put Bosch or Denso in my lawn mower much less my car.
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  14. Gearbanger 101

    Gearbanger 101 Straight Outta Locash Super Mod

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    You wouldn't be blowing spark blow out with that little blower. There are guys running twice the boost you are that aren't experiencing spark blow out.
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  15. Paul1981610

    Paul1981610 Member

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    Give me some more ideas
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  16. sneaky98gt

    sneaky98gt Mustang Master

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    How do you know it's going rich at WOT? Are you looking at it on a wideband? Contrary to most folks' intuition, spark blowout actually reads lean on a wideband. That's because the wideband is an oxygen sensor, and not a fuel sensor. Fuel not burning due to the spark blowout results in oxygen not being consumed, and thus a lean condition registered by the O2 sensor.

    OP, buy a set of NGK TR6s. Last set I bought was only like $13 for the set. Gap to .030. If you still have problems, the spark plug isn't likely the issue.
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  17. Paul1981610

    Paul1981610 Member

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    As noted in my MAF thread that I realize I should have stuck with. Car was running good just a little low rpm (under 2k) stutter. Had gears installed came home cleaned MAF and installed speedo cal. Took it out and ran like crap in boost. Blowing black smoke and jerking. Thought I had screwed up MAF. bought a new pigtail and MAF. Still the same but not quite as bad. Realized since I am new to superchargers the plugs I had installed were garbage. Bosch platinum +4. Installed a week ago. So I pulled them and installed Autolite 103 gapped at .035. It is much better but still black smoking at high boost. My thought was with the Bosch multi tip and a dirty MAF it was fine. But now with a clean good reading MAF the Bosch just didn't work. Could I have messed up the ECM with the speedo cal. The ECM is flashed by Saleen.
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  18. Paul1981610

    Paul1981610 Member

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    I removed the speedo cal just to make sure but to no avail
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  19. stangr5oh

    stangr5oh Active Member

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    The ECM should recalibrate on its own the stock parameters unless you has a tune. But you may want to try and disconnecting the battery for 30 sec. and then reconnect and see if that makes a change, I am just throwing that out there as a maybe, but then again it may do nothing.
    #19
  20. Paul1981610

    Paul1981610 Member

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    If you have a tune and disconnect a harness it can't "untune" can it? I mean the ECM can't store multiple tunes ie stock or tune right
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