Spark plugs and alcohol injection

[Hard AttacK]

Would you guys run a colder or hotter plug? Im just running ngk coppers right now and it seems to sputter up in the rpms like the plugs aren't firing to their fullest. I also have them gapped around 27 so that might be a little low.....any thoughts?

[Hard AttacK]

I should add that i cant lean it out without knock past mid 11 afrs even with like 75% alcohol

[kywhitelightning]

All pertinent info for the question is missing. Coppers, iridiums, or platinums all will do the same thing. The precious metal plugs just advertise longer lifespan. When raising HP levels a one step colder plug is recommended for every 75-100HP increase. Alcohol injection changes nothing as far as plug choices go. It's all about the power level for varying the heat ranges and gap settings.

.027" is a pretty small gap. Depending on your current power level, you may want to look into refreshing your ignition system or even add an amplifier.

With an HKS DLI I was able to run .030" gap at 550WHP without issue on NGK iridium 8's. Near 700WHP I changed to NGK copper 8's without a significant reason to other than price and had to gap them down to .025". There is no difference between the two other than price IMHO. Coppers win in my book.

Jeff

[Hard AttacK]

Thanks bud. I believe theyre actually nickel? 7 heat range.

I ordered copper 7s non resistor and hotwired my coils last night in hopes to run a bigger gap. New coils + boost a spark are on my christmas list

[CoopKill]

Jeff how much life did yoi get out of the iridiums? I had crap luck with them at BPU levels with 12-13lbs boost. 2 sets lasted 3-5k, and like a light switch blowout started happening. One set before new coils/dli, and one after.

[kywhitelightning]

I never had issues with them that weren't there with the coppers, ie blowout happened with the same gap settings and the same power levels. I switched because I was told the iridiums had a higher likelyhood of blowout based on design and proved that inaccurate. There were also myths floating around about precious metal plugs possibly causing detonation when ran with alcohol injection. Also false. Just because of price, I will never run another precious metal plug in my car. Both seemed to perform equally given the same conditions with the iridiums costing 2X more and requiring special ordering. I'm pretty sure I bought my coppers off the shelf at the local advance auto for ~$4/plug and the iridiums were ~$9/plug. I've changed plugs just to keep new parts in the car to always keep it in tip top shape. Pretty much every major teardown gets new spark plugs. I doubt I run a set past 10,000 miles due to upgrades or parts breakage. This last teardown has the same old plugs back in it though. Had to save money somewhere as those were on a VERY short list of parts reused.

Jeff