kenamond
DSM Wiseman
- 3,225
- 67
- Feb 15, 2006
-
Los Alamos,
New Mexico
The BPR6ES are for a mostly stock to slightly modified car. If you're pushing 18+ pounds of boost, you'll want to go with a colder plug, which are the BPR7ES. And then if you're pushing so much boost that you're blowing out the spark on the 7's, you'll go with an even colder plug - BPR8ES or BPR9ES. The higher the number, the colder the plug.
Actually, you need a colder plug at higher boost, because the plug has to conduct more heat out of the electrode and into the head to prevent/avoid preignition and detonation.

