Yeah 8000+ is the sweet spot for the 1.8. Anything less and it really doesn't come alive IMO. K&B 1L plugs worked the best for me. The OS F kept burning up on me. The 1L's lasted forwever and were 1/3 the price. NO NITRO !!!!! The engines run best without it.

Instruction sheet (only 1st page).
http://www.rcuniverse.com/forum/upfi...34/Xv64158.jpg