Racing fuel

[BIKE DUDE]

I haven't seen any of that around here in years but I'll just stick with what it says in the owners manual.

 

[roadthing]

Gen1 bikes are set for 89 Octane (r+m)  Gen2 is 91

octane has nothing to do with burn rates/speed/heat output..  the ONLY thing octane indicates is a fuels resistance to ignition. (short answer)  

thermal output (identical)
burn speed (identical for all practical purposes)....

there are "oxygenated" fuels available at some tracks that will increase power output. As the fuel burns, it releases captive oxygen and allows a fuller fuel burn and so more can be added.. (nitrous does the same thing)

The oxidizers used "can" be harmful to many fuel system components btw..

The only way your bike will go faster is because the weight of the money you spent out of your pocket will lighten the bike...

You have some good information in your answer. However your statement about the thermal output, and burn speed being identical is a little off. Flame propogation will be the same, but the rate of burn for the fuel will be slower with a higher octane fuel.

 

[Professor]

WOW....... i think thats the smoothest A/F #'s i seen yet on these bikes

 May i ask who tuned it? and with what exhaust....brocks?

It is a Yosh. A very streetable combination. Jim Sabin in Dallas tuned it.

 

[Draco1340]

Gen1 bikes are set for 89 Octane (r+m)  Gen2 is 91

octane has nothing to do with burn rates/speed/heat output..  the ONLY thing octane indicates is a fuels resistance to ignition. (short answer)  

thermal output (identical)
burn speed (identical for all practical purposes)....

there are "oxygenated" fuels available at some tracks that will increase power output. As the fuel burns, it releases captive oxygen and allows a fuller fuel burn and so more can be added.. (nitrous does the same thing)

The oxidizers used "can" be harmful to many fuel system components btw..

The only way your bike will go faster is because the weight of the money you spent out of your pocket will lighten the bike...

I have to disagree with a lot of what is being stated.

Gasoline energy content varies enourmously, from 113k to 117k BTUs/gallon in the summer down to 108k - 110k in the winter. Thats a 15HP difference on our bikes. Ever notice how miliage goes to hell in the winter. When most states switched over to RFG (the new reformulated stuff) the BTUs dropped even further another 1% for summer blend and 3% for winter blend. The RFG blends contain oxyginates (ETHANOL)that as a side benifit to the manufacturer is a cheap way to increase the octane. If you have a datalogger and you map for it, you can gain back this loss in power by adding more fuel to compensate for the small amount of O2 that comes along for the ride, but gallon for gallon you will typically get less power from higher ocatane pump gas because there is more ETBE, MTBE and ethanol. Brock and others also recomend 87 pump for the GenII. Another thing to consider (for racing) is that you can loose about 3-5% of the BTUs leaving the fuel in a plastic container for a week. The high volitiles can diffuse through a blow molded jug in very short time. Gas needs to be stored in steel. I won't go off on burn rates, but the statement that burn rates are identical is not scientifically accurate.

I have run several hundred passes on my GenII at 152 to 153mph with 87 pump gas, BUT I'm one of those geeks that datalogs and adjust A/F for the fresh fuel I bought and the track conditions that day. I also monitor for detonation. If you aren't monitoring the motor and adjusting for different fuels and air conditions, I would conceed that higher octane is probably best.

 

[Scooter1984]

Yup.
In fact you will actually go faster with 87 octane. You want to run as low an octane rating as you can without detonation. To run 100 or more you would have to advance the ignition to compensate for such a slow burn. Probably the best fuel at the track or the dyno is MR9 at 87 ocatane, and if your are mapped for it is good for an extra ~10 HP. MRX01 is good as well at 90 octane. Both are expensive and tough to get. I would recomend good old 87 pump gas.

I have 2003 busa and run 2gal of 110 in full tank mixed with 91 and I see great response gains as well as power gain

 

[Scooter1984]

It is a lot cleaner fuel I've been told to as it is not petroleum based which also means it will not go bad as regular pump gas will

 

[mjl3truck]

It is a lot cleaner fuel I've been told to as it is not petroleum based which also means it will not go bad as regular pump gas will

Post your before and after dynos please.

 

[ali123]

It is a lot cleaner fuel I've been told to as it is not petroleum based which also means it will not go bad as regular pump gas will

ITS SCIENCE