1FastRedSC

If the heat range on the spark plug is high enough, i could see it getting hot enough to act as a glow plug and causing some detonation, but i don't know for sure. I do know from messing with bikes and atvs (especially 2cycles which get really hot) that running a spark plug that's too hot can result in a melted piston.

jimbo1111

Try installing a set of platmum plugs. Do a few high boost runs and let me know what happens.

samluke

I am one of the disbelievers/naysayers of the NGKBPRES. I have a 1989 944 Turbo Estock car. I have tried single electrode Bosch platinum against the NGK's on two seperate and independant occassions, once in Maryland about 4 years ago and just recently here in kansas City on Imagine Auto's dyno. On both occassions the dynos showed a consistent improvement with the Bosches of 4-5HP, over brand new NGK's gapped to the "magic" numbers. The Bosches were again a good return for the money and I certainly won't be going back. It would be nice ro try something different, the next dyno session will be with the Beru Silverstone S7, perhaps I can find a couple more HP, which means everything in stock class.

TurboTommy

The reason copper is recommended, is because it's a very good conductor to help with consistantly jumping the gap in a high pressure environment (turbocharged). That's the only reason.
Apparently, silver is supposed to be even one step better, yet. Don't know if the silverstone is actually silver or just marketing hype.

Anyway, copper wears faster (they don't last as long), so some people think they're doing you a favour by recommending another material type plug. (It doesn't matter in a NA engine).


Now getting back to the tip-breaking issue. I would certainly entertain a copper NGK if the f@#&king tips are prone to breaking with the Bosch!
So, what NGK plug would be a direct replacement for the stock bosch WR7DC (which is copper), EXACTLY?

35thSLP

I am running Beru Ultra-X Spark Plug, UX79.

1FastRedSC

I'm kind of wondering the same, because i looked up the wr7dc and it cross referenced over to a bpr6es (ngk's numbering scheme if you didn't know btw is backwards, lower the number, higher the heat, higher the number, lower the heat) which would be a hotter plug than the bpr7es. Does that mean that you guys are using the 7 to get as far away from detonation as possible under boost without fouling the plug?

JET951

ive tried many different sparkies in my car including 4 electrode. no difference i can feel sorry

special tool

You can get the silver from Bosch - wr7dS - S instead of C at the end. I have a set, but I haven't dyno-tested them.

Also - keep in mind guys that the difference is only seen when you are up against detonation - usually at very high output.

HIGHBOOST

bought my NGK's today, just $1.89 a pop, can't beat that!

1FastRedSC

Maybe one of you highboosted cars could try out those iridiums. Ngk iridiums are between 6.50-8.50 a plug, and are supposed to be made specifically for the high engine output crowd ie motorcycles and force induced engines.

special tool

Fast SC - yes, it is one step colder than stock. The BPR7ES is the best plug for the 951.
You can use the 6 in winter if you are in a cold area.

Friendan

Just buy the NGK's and replace them often. You guys in the States can get them for $2 a pop, so you might as well. I can get them up here for $4CDN a pop, still well worth it for me. Plus we only have to buy 4! Cheap insurance/maintenance.

UK952

Just out of interest as you seem very certain, what other plugs have you tried ST?

DFASTEST951

Do plugs REALLY make that much of a difference? If so, how?

gstreev

I'm running Bosch Platinum +2, seems good.