Race fuel in 400ex

The need for race fuel all depends on compression ratio. I have a 11:1 and i run a 50/50 mix of vp110 and 93 pump gas. If your 13:1 or higher you pretty much need straight race gas to get the full potential out of your engine. With 10:1 or 11:1 you can run straight pump gas premium and be fine. I notice alot less ping with the 50/50 mix i run and it does run cooler. I never really cared for the smell. LoL my .02

I'm thinking about trying either a mix or straight, I know it's a high comp piston but not sure the ratio. Mainly want it to run a little cooler

If its running abnormally hot i would suggest looking into the jetting. If its lean you will run really hot and eventually burn it up. Also any idea if it has big bore kit? Could it be a 440? These are all concerns that could be why its getting hot. You can get air shrouds to direct air at the oil cooler, a bigger oil tank, or add another in line oil cooler. All these things are made by an aftermarket company called cfm. Just things to look into.

It's not getting to hot right now I just herd that race fuel might make it run a little cooler which is always nice, I know cfm I got there air box/battery box and plan to get the oil tank