[fia#09]

Before building my motor, I researched this. Spoke to the owner of one of the companies that produces the stuff, asked for any dyno tests, and chemical explanation of exactly how much "boost" you get. No credible documentation. The boost is a minimal amount. My 1200 Sportster pinged on everything except sunoco 94, and even a stale batch of that. That had a 9:1 CR, but a poor combustion chamber design. Pete at ERA said stay at or below 10:1, and 9.5:1 with cast iron heads, and I concluded exactly that. Smokey Yunick said there is no way to hear detonation at the end of a straightaway, so stay well away from the problem. Check out the HP formulas for detuning a race engine and you will find that lowering the CR only reduces the HP by a minor amount. New cam, etc. technology is a much better way to build HP. Having said that, if an engine is pinging lightly the stuff will usually overcome that , but it stinks, is messy, voids warrenties, and is diminishing returns dollarwise. I carry it and use it in my tow vehicle when towing, but generally not in the Cobra.