[@wot]

I have tried various additives etc. with marginal success. Most of them help slightly, and in a pinch you can add some and get to where you are going, driving carefully. If you want to tune and time a hi-compression car correctly, you have to buy race fuel. The engine will run stronger and cooler, not to mention the grin on your face will be bigger. Buy a 55 gal. drum and use all summer.