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So I think I'm going to be dynoing my car soon and I have a quick question about how the octane in gas affects horsepower and what not. I have a nitrous fed civic and always use 93 octane. Its always worked great. Now the question is, would I be gaining power say if I would put in 96 octane or 100 etc? I had always thought you put higher octane to avoid detonation but you would be losing some potential power for the sake of safety. Let me know your thoughs fuel gurus.

 
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Well your right about 93 octane. It is recommended by Holley to run at least 93 octane to avoid Detonation. But I'm not sure if runing any higher numbers would be better or worse. That would be helpful to all of us on here since you are going to be running on a dyno... you could try a couple of variables then post your findings. Just start small then go higher a couple of points at a time.

 
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the only real way to tell would be on the dyno, and that can be hard to do since you need to run the new fuel at least 2-3 tanks before dyno again.

 
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hmmm, someone has to know the answer....

 
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the only person that will know is someone running the exact same setup as you who has done a dyno. Every car is different and under different conditions. There isn't any known octane. You might be able to work it out based on the compression ratio while using nitrous but i have no idea how.

 
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Well, I'm looking for a general rule for people with nitrous. Whats the rule for turbocharged cars? I think they get higher numbers with better gas but I have no clue.

 
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Octanage affects the piston displacement inside the combustion chambers... more octanage = more displacemnt with the same amount of fuel... more displacement = more power... since the piston travels faster... now rep me!

 
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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.


hence since it can be compresed more... the kick the piston gets from the explosion makes it travel faster... so to sum it up yes it will give ya a few ponies more... given u have the rigth amount of A:F...

 
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for turbo, the minimum is 93-94 but depending on how much boost (more boost = more compression) you may have to use higher.

 
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I basically, too much octane seems like it can hurt performance because I would bet my compression ratio isn't high enough to justify 100 octane. I think I might just do 3 runs, N/A, Nitrous 94 octane, Nitrous 94 octane+NOS fuel booster. I've heard good things from that product. Expect a dyno before the new year.

 
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ya higher octane than you need = more carbon deposits = worse performance

 
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Bigger isn't aways better!

 
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erm? well all i get here at the pumps is 95 and 93 oct unleaded and they dont seem to be damaging my performance....

 
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Dude, putting higher octane is not going to give you more displacement.

Octane is the abilty to compress the fuel more, that is true. But putting better gas in doesn't change the compression ratio of your engine. The min to raise compression is to mill the heads, which means you will have to take the heads off (which is a bad idea on Hondas), but in any case you have to do something physical to the engine, noit just put more gas in.

The answer the thread starter is looking for is that NO, higher octane will NOT give you any more power. It will help prevent you from blowing your engine because of preignition, but it will not give you any more power.

It will give the ABILTY to make more power, so if you want to spray more, you will probably need higher octane. But if you have been fine with 93 octane at your current nozzel setting, then there is no reason to change now.

 
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Don't watse your time or money with fuel boosters, the only raise your octane about 2-4 points, you need 14 points to go up one octane, so if you put 2 bottles in, you'll run like a 94.3 octane, not much difference.

As for harming your motor, you won't do much running just 1 or 2 tanks, as long as you stay with unleaded. Sometimes you get into the higher octanes and they start running leaded fuel, that is REALLY bad for fuel injectors.

 
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i'm just happy i get to go back to 87 with the stock head back on soon