I keep killing spark plugs...

I was experiencing detonation with iridium plugs, so i swapped with new iridiums was better, less detonation but started to get worse again.

I have now switched to NGK coppers, again it's ok at the moment but it was with the new plugs.

I get a few months out of the plugs before the die.

I am running a squirt of water / methanol.

Gapped to 0.65mm, Heat range 7.

Maybe switching to Coppers they will hold up now. Time will tell but the Iridiums didn't last long at all.

I wouldn't think it's your plugs but maybe your tune?

I've switched out spark plugs more often than some as well but that's because my cars been on the dyno a few times so we switch out before each time.

Please don't quote me on this because its been a while since I did my build but arent you supposed do go one range colder for turbo on the ngk's? 6?

kookoo4nsx said:

Please don't quote me on this because its been a while since I did my build but arent you supposed do go one range colder for turbo on the ngk's? 6?

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That's what I always ran, Still do With the SC. I do think it's your tune though

This sounds more of a tuning / charge temperature issue. If the damage to the plugs is from detonation, I'd be concerned what's happening to the softer / more brittle aluminum pistons.

Thanks, i will get the tuned looked at as a first port of call and also try colder plugs.

When i pull the plugs, they do look in a bad way for the mileage.

jaffaz32 said:

Thanks, i will get the tuned looked at as a first port of call and also try colder plugs.

When i pull the plugs, they do look in a bad way for the mileage.

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Please post pics of your plugs.

Also, your heat range 7 plugs are already colder ( higher # = colder)

It does definitely sound as if your tune is very wrong.