fuel octane
what octane rating are you using? motor, research, or average of both? the sunoco 110 is 106 motor. vpc12 is 108 motor or 112 average rating. the 110 average is minimum. what rpm? stay under 7000, no NOS. heavy car? or over 7000rpm its safer to go with a better fuel. Main question to ask is how much did you spend on the engine? wanna blow it up being cheap? if money is an issue, dont race. poor fuel will eat rings and bearings. most guys blow an engine up never really understanding why.