What octane fuel are you running?

From the Sunoco web sight.

This is for their 116 race fuel. "Static compression ratios up to 17:1"

http://www.sunocoinc.com/Site/Consumer/RaceFuels/TraditionalFuels/Maximal.htm

This is for their 110 race fuel. "designed for competition engines with compressions up to 13:1"

http://www.sunocoinc.com/Site/Consumer/RaceFuels/TraditionalFuels/Standard.htm