Originally Posted by
speedracerntrixie
QWK, you just jogged my memory. For our racing series we have to be able to idle down below 4,000. For the first heat I would use the Enya 3 as that is the only time the idle was verified. Then I would switch to the OS 8 to gain a little more top end. If it got hotter then 90 that day I would switch to an MC59. Obviously in regards to this post it was overkill.
While it is true that colder plugs give better top end performance, the idle quality is not as stable by comparison to a hot plug. In the models I run, idle quality is far more important than top end performance. Some engines don't transition well if idled too fast (or conversely too slow). When I finally get flying, my thoughts may change some.