Minimum plug gap?

Discussion in 'PSI Superchargers Tech Questions' started by Bjs344, Aug 15, 2022.

  1. Bjs344

    Bjs344 Member

    Sep 10, 2013
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    I’ve been in left field with this car for awhile now to the point where I can’t even tell if it’s running on all 8 or not. I changed a bunch of stuff and went testing and had similar lackluster performance as usual (down a couple hundred horsepower). I realized yesterday that I had made most (maybe all) of the last 4-6 passes with #2 plug gapped at .005. IGN1A coils and ngk10 plugs. 40 psi boost on methanol.

    The pipe was normal temp at idle the one time we checked on warmup but I don’t record egts going down the track.

    what’s the chances #2 was firing?

    It apparently backfired that cylinder at some point because it blew apart the end of that header pipe where it meets my 5” collector. Sounded great though. I even had a guy compliment me on how fast the car sounds (well, maybe it was a compliment, maybe it was a nice way of saying it was slow)
  2. MaggiFinn

    MaggiFinn New Member

    Dec 3, 2019
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    It's often funny, how the best of passes are made without the full set of cylinders firing.
    You very likely can see whether it was firing by the condition of the rod bearing. If you suspect a cyl being dead in a pass, its time to check the rod bearings.

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