06 12:1 on race gas

[angry450r]

so I got an o6 we all know it has 12:1 compression. my question for you all is will it gain any power on 108 octane. I know the miniumum is 93 but are there truly any gains from adding race gas?

[Smidgy]

You can gain some benefit with higher octane fuel. 108 octane was made so that a supercharged engine would run at 108%, This was made so the fuel would not auto ignite at higher compressions of the supercharged engine, which were making engines knock. In other words higher octanes don't burn as easy and require more energy to make them ignite, which will stop you from getting engine knock(pre igniting the fuel).

So in our case, a 2006 450r should be able to run a higher octane level than an 05 450r, 12.0-10.5 right. This means there is more power there, energy in=energy out and if you put more energy into burning something you will get more enegy out.

So all i got to say is try it and see what you get out of it, it may be too small of a difference to justify, or it may be major, it all depends on how much burning energy your 2006 can provide, to get full benifit you may have to goto a better ignition which will create a larger spark to light the fuel, anyways I hope this helps

[s2k1]

No, you probably won't get any additional power from 108 octane if the fuel is all that you change.
The higher the octane, the slower the fuel burns. Actually, an engine designed to run on premium fuel will usually make less power on high octane fuel.
However, if the ignition timing is retarded from the factory due to compression ratio, combustion chamber design, etc, there might be power to be gained by going to higher octane fuel and retuning the ignition timing curve.
Bottom line, if you aren't changing the ignition timing with an aftermarket programmable CDI, don't waste your time with race gas (in this specific application).
Good question. :macho

[Smidgy]

This is not totally correct, the fuel doesn't burn slower, it takes more time in the compression cycle for the fuel to ignite, lower octanes will burn under less pressure than higher ones. ex diesel fuel low octane ignite under pressure-108 high octane can stand higher compressions. It is in the genetic makeup of the fuel, different additives give the fuel a different octane, not make it burn slower.

I do agree changing the ignition timing is the secret to making this work, and a better ignition maybe needed to compinsate for the engine being designed for premium pump gas, this maybe to costly for your application, but i think it could have great rewards in a race enviroment, where you will be buying programmable CDI's and money is not as much of an issue.

[angry450r]

thanks for all the information guys well either way I bought 5 gallons at the dragsrtip so I got it and will try it and see what happens I know it wont hurt. one point you made that intrests me is about ignition timing being retarted and higher octane might help, well I know my quads ignition timing is retarted. they did that on the e- start ones to ease up on the starter so we will see what happens

[s2k1]

This is not totally correct, the fuel doesn't burn slower
Actually, it is correct. Do some research. The higher the octane, the slower it burns. High octane is only used to prevent the mixture from igniting prematurely. Detonation and pinging are hard on an engine. You want to control the timing of the combustion process, not let it auto-ignite.

[Smidgy]

man that is what I just said, that doesn't even make sense it burns slower, I DOESN"T BURN SLOWER!!!! I am an engineer man i deal with this stuff all day, don't tell me this bs, THE OCTANE IN A FUEL IS A RATING OF HOW HARD IT IS TO LIGHT UNDER PRESSURE. not the rate at which it burns, i have done my research.

You are right it does stop pinging and detonation, from not autoigniting UNDER PRESSURE of the compression stroke. Not buy burning slower, but by not igniting until the correct time.

[FHKracingZ]

You can lose power if you are running race gas and you dont need it. It takes longer to explode and takes longer to fill the cylinder gas. When you run high compression you gotta have equal pressure accross the top of the piston. Ping'ing comes from uneven pressure points on the top of the piston.

[Smidgy]

That is right, if you run too high of octane, and the fuel doesn't ignite like its supposed to(at a specific time just before TDC) then the ignition will be too late, and it will not be pushing the piston down at the time it goes past TDC, so you will loose a ton of power, as the engine wants to stall for this brief moment as it is only working off its momentum. Then the fire catches up to it pushes it so your running again but now it burns to long, because it was late, and (if real bad) is still pushing down on the piston as it starts its exhaust stroke, opening the valve, and pushing burning fuel out the pipe, for a very brief period.

[ilpadrino113]

the fuel doesn't burn slower, it just takes more energy to ignite