FZ6 on Race Gas!

[bmccrary]

To start off with: Are any of you guys experiencing a fuel shortage? Here in Charlotte, gas is hard as hell to find. About 90% of the gas stations are out of gas. Those that do have it are only carying 87 Octane and there is a 10 gallon limit. Yet prices are around 3.99. Seems kinda odd that they aren't an higher than that with the shortage. Dang pocket robbin' crooks.

Anyway, the other day I was out on the bike trying to enjoy whats left of the main riding season and I was extreamly low on fuel. I rode around for a while tying to find gas, but on one had any. Finally I found a station that is right next to the Speedway. This station not only carries the usual octane levels but race gas (100 octane) as well. Sure enough they were all out of 89 and 93, but they had 100 in so I opted to put the 100 octane in.

I have never put 87 in, nor do I plan on it. Since the bike isnt rode very day there would be no telling how long that low octane gas would sit in the bike and by time I got around to riding it, the level could be below 80.

So I put a couple gallons of 100 octane in a 5.99 a gallon. Heck the 87 was still 3.99!

There was noticble difference in the roll on power. I.E. 3rd of 4th gear low rpm and a handfull of throttle. The motor wound up quicker and much smoother. Higher RPM's seemed to be smoother but not much faster.

Overall, the bike doesnt have the electronics on board to fully take advantage of the higher octane, however the hotter and more even burn did make a difference in roll on. I wont run race gas on an everyday tank, but it was fun to see how it did with it.

Oh and walmart and the local autoparts stores are all sold out of octane boosters and such....


-bryan

 

[dhall615]

Hmmm would like to try this but money is kinda tight now and 4$ a gal for 87 is just right for me now.

 

[dickieD]

i wouldnt recommend this.. FZ6's are fuel injected and race gas is leaded. it can mess up ur injectors.

 

[wrightme43]

It depends on the blend where you are.
There are oxygentated fuel race blends
Leaded fuel race blends
Unleaded race blends.

But for sure dont use leaded with a cat conv very often.

 

[bmccrary]

Its not leaded. Sticker next to it said unleaded.

-bryan

 

[dhall615]

I havent seen a sticker for leaded race gas at a normal pump before.

 

[grumpy1luvs2eat]

We are paying $3.80 for 93 octane here in Mississippi. I have a source for 101 octane, but they want $6.99 and I'm not there yet with that price unless I have no other options for gas. GRUMPY

 

[bmccrary]

I havent seen a sticker for leaded race gas at a normal pump before.

Yeah. The only reason they carry it, is due to the number of ppl in the area that run at Mooresville dragstrip and some of the surrounding dirt tracks and such. There are several guys that have high number street cars that will only fill up there.... Lot of money there.

-bryan

 

[GastonJ]

The octane of normal unleaded fuel in the UK is 95 RON, super unleaded is 98 RON. 98 RON cost slightly more, but I din't bother. Is there a specific reason for such low ratings in the US?

 

[D-Rock]

i wouldnt recommend this.. FZ6's are fuel injected and race gas is leaded. it can mess up ur injectors.

street legal race gas, the kind sold at a pump, is unleaded.. just FYI.

 

[opds9091]

:spank: here in cape caoral FL,, gas for 93 oc is $3.89 :spank:

 

[bmccrary]

Yes we are getting raped!

-bryan

 

[Howattzer]

I live in Canada, and I am paying $1.35 a Litre. That works out to $5.14 a gallon, or approx $4.80 USD for a Gallon of 87 Octane. It has been that way for almost 1 year. No sign of decreases in the future. I wish I was only paying $3.50.

 

[dako81]

Higher Octane doesn't burn hotter. It actually burns cooler. It does burn more consistantly though.

 

[champion221elite]

Higher Octane doesn't burn hotter. It actually burns cooler. It does burn more consistantly though.

I was waiting for someone to bring up this point. Octane is added to fuel in an effort to control pre-ignition. Pre-ignition is brought on by high compression and the fuel spontaneously combusting due to high heat and pressure. 87 octane fuel actually contains MORE BTU's per gallon and will explode at lower temperatures than say 93 octane, and especially 100 octane fuel.

Introducing 100 octane fuel into an engine programmed for 87 octane fuel will actually produce less horsepower and have slower throttle response. Furthermore, higher than required octane ratings will accelerate the buildup of carbon deposits since the fuel is actually burning cooler than Yamaha engineers anticipated when designing the motor.

I've experimented with different fuels in my 1997 Mercury 225 EFI outboard. My best holeshots, and top speed runs were made with 87 octane fuel (which Mercury specifies for my motor).

Bottom line, 100 octane fuel can be used in a pinch, but it's not what the FZ6 motor was designed to run on. The electronics and factory compression ratio simply cannot use the available octane. The result is wasted money, and accelerated carbon deposit formation.

 

[bmccrary]

I was waiting for someone to bring up this point. Octane is added to fuel in an effort to control pre-ignition. Pre-ignition is brought on by high compression and the fuel spontaneously combusting due to high heat and pressure. 87 octane fuel actually contains MORE BTU's per gallon and will explode at lower temperatures than say 93 octane, and especially 100 octane fuel.

Introducing 100 octane fuel into an engine programmed for 87 octane fuel will actually produce less horsepower and have slower throttle response. Furthermore, higher than required octane ratings will accelerate the buildup of carbon deposits since the fuel is actually burning cooler than Yamaha engineers anticipated when designing the motor.

I've experimented with different fuels in my 1997 Mercury 225 EFI outboard. My best holeshots, and top speed runs were made with 87 octane fuel (which Mercury specifies for my motor).

Bottom line, 100 octane fuel can be used in a pinch, but it's not what the FZ6 motor was designed to run on. The electronics and factory compression ratio simply cannot use the available octane. The result is wasted money, and accelerated carbon deposit formation.

Interesting....

Not that I don't believe what you are telling me, but you have my interest up now. Going to do some research on this.

Thanks for bringing this up.

-bryan

 

[champion221elite]

Cool... I look forward to seeing any info you can pull up. Here's a quick definition of octane and it's application inside internal combustion engines

Octane rating - Wikipedia, the free encyclopedia

I know it's not a motorcycle, but my bass boat literally jumps out of the hole when running 87 octane fuel. I've run up to 93 octane gasoline and found my engine's performance was sluggish. It was slower to plane and nearly 1 mph slower on GPS. As it turns out, the EFI 3.0 liter V-6 engines were lower compression than the 2.5 liter engines. As such, they don't require the same higher octane fuel to prevent pre-ignition and detonation.

 

[kemmer]

Another point to clarify, octane is not something that is added to gas. It's just a measurement of what pressure is required to cause the fuel to pre ignite.

 

[craig007]

This could be a good topic for mythbusters. There are many ways to make a 100 octane gasoline. If you load up the fuel with something like ethanol (octane of 102), then you get a lower density fuel with less heat content so lower power. If however you load make 100 octane fuel by loading it up with, say toluene (octane =120), I think you get a different story. In this case you get high octane and high density and high heat content and probably higher performance. This could explain the different experiences that you both had.

I would also bet that they would load up a 100 octane fuel with high doses of additives, so I would not worry about engine deposits. Also, after the spark fires, the temperature in the cylinder (and the pressure) is just a function of the fuel/air ratio and the heat content of the fuel (assuming that all the fuel burns). So again, it depends on how the high octane was achieved.

 

[bmccrary]

I have always known that the higher the compression ratio the higher the needed octane. It has always been to my knowledge that the good rule of thumb is that anything much over 12.5:1 is pretty much in need of octane higher than 93. 13:1 really being the major line.

But with the compression ratio on the 2009 FZ6 being at 12.2:1 as noted on Yamaha's site. (Assuming they havent adjusted that since the release in 2004 or 2005) A higher octane would be of some help rather that hurt. I am not sure what the C.R. is on your outboard or atleast I may have overlooked it, but I would assume is lower than that of the FZ. Seeing as how the motor has to last longer at extreame conditions, ie W.O.T for extended times.

I am currently taking Thermodynamics 1 and I am starting to learn about pressures and such of various gasses and conditions so I imagine I will learn more about this topic as the semester goes on.

As in regard to heat, the temps of the bike were warmer than what was expected. I was running highway for a while in lower 70 degree weather which in the past has always kept the bike in the 2bar range in coolant, esp at highway speed. (I wish the bike had an actual degree read out over that bar system.) However, that night I was running 3bars.

I have always heard that due to the higher octane that the burn is hotter and is a more even burn do to the higher refining process.

It would make since that with this more "pure" substance that it would ignite quicker and faster than lower grade. This would cause more burn on the intake valves and could be adjusteded by retarding the spark a touch. However, too much retard would put excessive strain on the valve train and would risk failure there.

(But on a side note, to those that are reading this.... this is how, to my knowledge a two step works on a car. The retarded spark timing alows the fuel to ignite late and puts more heat out the exhaust to help spool a turbo/turbos :Flash: with out a load.)

I do not understand how a more refined fuel will leave more deposits on a motor than that of a less refined fuel?

On a lower compression motor I could see where the higher octane would cause a inverse effect on power and could create the poor throttle respose. However with the semi high C.R. that the FZ motor has, I really doubt it is hurting it any. But like I said in the original post, I am sure that with more tuning and better electronics/software it could take full advantage of it.

I will do some research later on. As for now I have to find a mounting point for my new horn. "139db of ear piercing goodness"

-bryan