NGK Iridium IX plug experiment over.
#1
11-02-2009, 12:20 PM
NGK Iridium IX plug experiment over.
Well,
I had been running the NGK Iridium IX plugs with my MSD ignition system for a while. I was hoping for a little more longevity from my plugs as the MSD eats thru the coppers pretty fast.
I was getting random misfire codes from multiple cylinders around the 3K RPM mark at certain part throttle and WOT instances. And I blamed about everything I could think of, the MSD system, the wires, the cap and rotor, about 5 different plug gaps, everything except the plugs themselves.
It was the plugs.
Well, the plugs and the MSD combined, I believe.
I did a little research on the MSD box and the NGK iridium plugs. Here's what I found:
Seems as though an added "benefit" of the NGK plug is that they fire at about 5K volts less than the standard plugs. In an engine with a weak ignition (especially weak at high RPMs,) this could be a good thing. The problem is that the MSD box delivers 3 "regular" sparks per cycle at under 3K RPMS, and "one powerful spark" above 3K. I believe the "one powerful spark" was jumping the gap too early and causing misfires. Switched back to the NGK V-powers and the problem hasn't repeated yet.
I will say that the V powers have been the best plug I have found. The Autolite 3923s fouled too quickly (about 500 miles and they engine was noticably rougher), the Champion truck plugs were decent, but the NGKs have the smoothest idle and best off idle throttle response of all the plugs I've tried.
I had been running the NGK Iridium IX plugs with my MSD ignition system for a while. I was hoping for a little more longevity from my plugs as the MSD eats thru the coppers pretty fast.
I was getting random misfire codes from multiple cylinders around the 3K RPM mark at certain part throttle and WOT instances. And I blamed about everything I could think of, the MSD system, the wires, the cap and rotor, about 5 different plug gaps, everything except the plugs themselves.
It was the plugs.
Well, the plugs and the MSD combined, I believe.
I did a little research on the MSD box and the NGK iridium plugs. Here's what I found:
Seems as though an added "benefit" of the NGK plug is that they fire at about 5K volts less than the standard plugs. In an engine with a weak ignition (especially weak at high RPMs,) this could be a good thing. The problem is that the MSD box delivers 3 "regular" sparks per cycle at under 3K RPMS, and "one powerful spark" above 3K. I believe the "one powerful spark" was jumping the gap too early and causing misfires. Switched back to the NGK V-powers and the problem hasn't repeated yet.
I will say that the V powers have been the best plug I have found. The Autolite 3923s fouled too quickly (about 500 miles and they engine was noticably rougher), the Champion truck plugs were decent, but the NGKs have the smoothest idle and best off idle throttle response of all the plugs I've tried.
#2
11-02-2009, 12:33 PM
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