05 450r HRC Cam full exhaust jetted bla bla bla... I am thinking about running race fuel because the highest octane I can get is 91 from the pump, do you think I will benefit from that... Whats your take on the matter....

 

Whats the static compression and what altitude do you ride at? 11 or less, it's a waste. 11 to 11.5 at sea level in hot weather I would keep an eye on the plug. Anything over 12 your going to need good gas or at least mix.

 

Most times if the motor is not setup for high compression the racefuel will hurt more than help. Race fuel burns alot cooler and is harder to ignite. A lower octane fuel burns hotter and is easy to ignite.Thats why you get pre detonation with lower octane fuels. You use a higher octane to help with pre detonation but if you go too high it is a waste of money. Stay with 92-93 and it will be as good as you can get till you boost the compression.

 

If your machine doesnt require high-octane, it will actually hurt performance. High octane is for high-compression engines, becaust the high compression actually heats the fuel up when it's compressed, and if it lights too early, it will pre-ignite (pinging) and result in loss of performance- High octane fuel burns slower and is harder to ignite, correcting this condition. that's what it's made for. But if you put high-octane fuel in an engine that doenst require it, the fuel is that much harder to ignite and burns slower resulting in sluggish "flame propagation" as the engineers call it, giving you theoretically less power, not to mention a waste of money.

rule of thumb- find the lowest octane fuel you can run without pre-ignition (occasional light pinging is considered normal under load according to many service manuals) that way you know you are right on the edge of having the quickest burning fuel for your driving style without loss of performance or engine damage.