Thread: Swapped to E85 new which Plugs would you use

Originally Posted by tomtom123

Basically, I would perssonally start out with the hotter plugs. If I saw a little bit of knock I would try and have it tuned out. If that doesn't work, then try the cooler plugs.

So 104's being 2 ranges colder, might be fine. If you pulley down and start seeing a tiny bit of knock you can't tune out, you may want to try the 103's

With running higher boost levels with E85 along with more timing than a typical pump gas setup I tend to run cooler plugs just in case. Hotter or cooler plugs is only the rate at which the plug and dissipate heat......has nothing to do with how hot or strong the spark itself is.