Question about race fuel!!
- Thread starter Mike89
- Start date
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BadAftertaste
Well-known member
Running it is no big deal. However, unless you have high enough compression to need it to resist pre-detonation, it's a waste of money. Race fuels contain less energy (burn slower) than lower octane fuels. ideally, you want to run the lowest octane possible without going so low as to pre-detonate. Stock sleds will be happiest with the high test pump fuel.
^ Exactely what he said. I know a guy who sells race fuel to guys with stock sleds because they think it does something for them. Well it burns cooler and will probably be easier on the motor (so would not running it at all). I currently run 91 ethanol (I have to), but ran 87 octane in my D7 and D8 and had 3200 and 1300 miles respectively with no burn downs or detonation. The motor produces power from exploding the fuel and generating energy. The hotter the better without burning down.
In a 05-09 cat for example, you LOSE performance by even running 91 over 85 or 87. RUnning higher octane than you need costs both $$ & HP. Little bits for insurance are one thing, like a pump gas turbo running a 1/2 gal of race for safety... that makes sense, but someone running 100 in a stocker or a sled with a pump gas head... HUGELY wasteful.
Every day we see people say "it's cheap insurance"... well, no, it's not.
also, if you have a sled that needs 91 at 0 elevation... it does not need 91 at high elevation.
Every day we see people say "it's cheap insurance"... well, no, it's not.
also, if you have a sled that needs 91 at 0 elevation... it does not need 91 at high elevation.
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flying pig
Well-known member
you will build less power and run way richer on race gas than on pump fuel.
Quick Read from How Stuff Works
The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.
The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.
The octane rating of gasoline tells you how much the fuel can be compressed before it spontaneously ignites. When gas ignites by compression rather than because of the spark from the spark plug, it causes knocking in the engine. Knocking can damage an engine, so it is not something you want to have happening. Lower-octane gas (like "regular" 87-octane gasoline) can handle the least amount of compression before igniting.
The compression ratio of your engine determines the octane rating of the gas you must use in the car. One way to increase the horsepower of an engine of a given displacement is to increase its compression ratio. So a "high-performance engine" has a higher compression ratio and requires higher-octane fuel. The advantage of a high compression ratio is that it gives your engine a higher horsepower rating for a given engine weight -- that is what makes the engine "high performance." The disadvantage is that the gasoline for your engine costs more.
Yeah, don't run race gas in your stock setup.
But yeah, a 1/2 gallon or full gallon in a 10 or 12 gallon tank is no biggie.
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