hey Doc, you were discussing spark plugs with Krass and stated that you like the basic copper Bosch plugs over the platinum plugs. I put platinum plugs in my 87 944 NA and even though the car runs good it does hesitate throughout the rpm range under acceleration. Is this what you were talking about? Would I expect better and smoother performance with the basic plugs? If so, what model numbers do you recommend?

 

The problem i have seen with the platinum plugs is the electrodes break off over time, and obviously end up in the combustion chamber. They probably exit the exhaust valve fairly quickly, but I still don't like the idea of it. Also, just because there are 4 prongs on say a P4+ plug, the spark is still only coming from one prong. Obviously there are Bosch WR7DP's which is a single prong plug. In an NA model it isn't as big of a deal, but in a turbo car, they have been known to cause issues. Just keep your eye on them every 5k miles or so. Replace if they start looking questionable.

Also, the performance gain isn't really measurable from a plug alone. Typically any change you feel is probably because you are running fresh plugs.

I've tried them all, I have dyno tested plugs, and there isn't a significant difference to justify the extra cost. A stock bosch copper plug works great. In the 87 Non S N/A, it should be a WR7DC (copper)