Is the 4644 a resistor plug?Im gapped .028 with LQ9's. Been charging to 3.7ms. Been this way for 4k miles. I switched from E85 to 116 and got 800 miles before my motor starting stuttering under boost. I can roll out 8psi with no issues, get near 20 and its all over. This is on a 4644 plug.
I have some more 4644 to put in that Ill tighten the gap on a little, but did buy this morning some of the 2668 plugs to try out.
Ill also back off on the dwell some.