After burning a couple of electrodes off of plugs (BKR7ES) I was a little concerned about future use. I had heard of a guy with a Honda running a serious nitrous setup (low 11's) having the same problem and NGK recommending one of their racing plugs that cured his problem.

Today I called NGK and got hold of their technical service dept to ask their advice on what their recommendation would be with my particular problem. They were very careful about recommending another plug until I gave them the history of car, HP over stock, type of fuel being used etc etc. After about 3 phone calls back and forth they finally recommended their R5671A-8 racing plug. They also have stated that these plugs should work very well N/A as well. They say if you are running N/A all the time to drop down 1 heat range to the R5671A-7 and this will work up to a 50-75 shot as well.

I would not suggest that anyone just go out and change plugs for no reason but if you are having any signs of detonation or other problems its worth calling them and asking their advice, its just another resource available.

As soon as I get these plugs and try them out I will report back on how they worked out. They are not expensive either, just a tad more than your standard copper plugs.

Jim

 

Thanks Jime. Good info and please keep us informed (you always do).
Big Cracker

 

I use the Denso 3139 which is for the 300zx and is two steps colder...I was running as much as 55 shot only thru them but had not noticed any issues with the electrodes...

 

I don't have any problems until I get to the 125 and 150 HP jets, other than that the standard coppers, 2 steps colder work great. They even do a good job N/A as well.