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I have a 2017 Duke. Has anyone tried putting racing fuel in their 390? I have been mixing 1gal of CAM2 110 octane racing fuel in my tank along with 93 octane from mobile. Holy ****, it really livened this thing up! I can’t believe how much of an improvement in power I could feel with just using racing fuel. I want to fill up the whole tank with it just to see what difference it would make, but I’m worried about it running too hot. I know these things come lean from the factory and I’m not sure if using straight 110 octane would be good or not. Anyone know if it matters?
 

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I'm really surprised you're feeling a difference, you sure this isn't self-suggestion?

I'm saying that because, from what I know, high octane fuel in itself does not deliver more power, it only allows the engine to develop more power if it's tuned to exploit the higher knock resistance (which the octane rating describes). An engine that's set up to use a high octane fuel can be made to have stronger compression and more aggressive spark timings because the fuel is less likely to ignite on itself. But regular, "civilian" engines tend to be tuned for street gas and even if they have knock sensors, they only serve as a "downgrade to limp mode" in case you pour in bad gas.

In fact, premium fuel has slightly fewer calories per volume than regular because it's composed with more octane-rising additives. If your engine is not specifically set up to increase compression when it senses high octane fuel, you're generally wasting money buying premium. Knowing how cheaply the 390 is made, I'd be shocked to find out it has flex fuel sensors.

Now, maybe race fuel has some magic dust in it that does give more power, I don't know. Reading up on CAM2, it has a higher octane number and is leaded, both of these serve to fortify against knock, to allow aggressive tuning, not to automatically give power, so I'm skeptical.

Also, lead is really bad for you and everyone around you, please please don't ride that on public roads. Your bike's manual also state that you shouldn't use leaded fuels. There are other race fuels with high octane numbers than don't have lead, experiment with those instead.

As for the actual question, from what I know pouring high-octane (unleaded) fuel should not damage the engine. But that goes for premium street gas, I don't know for sure about race gas.
 

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Racing fuel ads more or less 10% power so the difference is notable, however for many reasons I recommend using over 110 Ron fuel for racing purposes only not using in public streets.

Sent from my ASUS_X00HD using Tapatalk
 

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"racing fuel" is a broad term, as VP alone makes nearly 40 blends for different applications. By and large, low compression bikes will run better on lower octane. The larger issue is the vast majority of race gas formulas need to be drained from the bike after each use, as they destroy rubber and plastic fuel system components with exposure....
 
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