Fuel

[RussMcB]

I've never run anything different than 91 or 93 octane pump gas from the Kwiktrip down the road from me here in Rochester or the Citgo station a few miles from RA. It's got ethanol in it as well as god knows what else but I have never in 6 national races failed a fuel test. It'd be pretty friggin ludicrous to fail someone for paying $2/gallon so they can actually afford to go racing versus $9/gallon at the track.

I decided a long time ago that if I ever got DQ'd for using pump gas I wouldn't care because my consience is clear. Of course, I'm not running for national points or anything like that, so a DQ wouldn't affect me as much as most of you.

I haven't heard anything that would make me think pump gas might damage my engine (especially since that is what manufacturers expect their millions of customers to use), and I can't see how paying more than $2/gal is going to make much difference in my lap times.

Wasn't there a different thread (FB engine of the year) where many people said a 4-5 HP advantage wont win a race because driving talent, chassis and race set up is more important?

[Wren]

Wasn't there a different thread (FB engine of the year) where many people said a 4-5 HP advantage wont win a race because driving talent, chassis and race set up is more important?

Around here everyone seems to be chasing either Cooper or Piper's car, so that would seem to still be true.

It's tough to stop people spending money and SCCA's resources are limited so I would rather see them ban the dangerous stuff.

[DanW]

No intention to imply pump gas would hurt the engine. Its about optimizing the engine tuning to the fuel you run. If 92 octane is sufficient to prevent detonation and the volume of ethanol in the blend does not cause a lean condition, go out and have fun. The fuel you buy in MN is likely much more consistent than what we get here in Kalifornia. Still, there are summer and winter blends produced with different vapor pressures and oxygenate content. There are also significant differences among brands, though not as much as in the past because of EPA blending formulaation rules.

The right distillation curve in race fuel can optimize throttle response. Ever count how many times a lap you put your right foot to the pedal?

VP and ERC are very good at marketing their "More HP in the Tank".

[sidney]

The cleanliness of race fuel is where it's at.
AV Gas may be fine for tractor motor FC's, but certainly not for 12,000 rpm screamers...
GC

FWIW...There's guy in Denver that develops fuel delivery systems for stunt and competition aircraft. He noted that AV Gas is designed for flat top piston engines (like a Pinto or a Kent). The flame path and air/fuel mixture is different than on a modern motorcycle engine piston (or any other newer vehicle for that matter). He may have been blowing smoke, but he makes a living doing this kind of analysis and design, and said AV Gas would not hurt, but not be the best performing fuel in a sport bike engine.

[Daryl DeArman]

:Wasn't there a different thread (FB engine of the year) where many people said a 4-5 HP advantage wont win a race because driving talent, chassis and race set up is more important?

I'd agree until driving talent, chassis and race set up is more equalized. Once that happens people will kill for 4-5HP.

The openness of the FB rules and the constant moving target with the engine package will, IMO, mean all esle will probably never be close to equal amongst more than 2-3 drivers and the fuel issue won't be a concern to the masses.

[Richard Dziak]

Spoke with the owner of our local road racing track who is an AMA motorcycle road racing champion.... I asked what type of fuel do you use in the racing bikes......


his response.....

"86 octane, it adds about 3-4 HP to the engine."

I agree with Russ McB, it does'nt make a difference to me as a regional racer about high dollar fuels or trying to add a few HP. I am out to have fun, and get the thrill and enjoyment of driving my beautiful Phoenix F1000.

Perhaps George Dean can weigh in here with his fuel recomendation of what he recommends for the regional racers vs the die hard National racers who want to be on the podium.

If I am correct in my own personal conversations with George he recommended high premium pump gas. Of course I am getting older and my memory is short.

[formulasuper]

Spoke with the owner of our local road racing track who is an AMA motorcycle road racing champion....

I agree with Russ McB, it does'nt make a difference to me as a regional racer about high dollar fuels or trying to add a few HP. I am out to have fun, and get the thrill and enjoyment of driving my beautiful Phoenix F1000....

And this folks, is why building a Formula S car with no rules for less money seems to me the way to go. We're just racing for fun anyway, so what if someone wants to show up with a Pro Formula Mazda, FA or some other high dollar car to run in FS, there will always be someone with WAY MORE money than the rest of us. There's only one winner, the rest are just having fun.

[SteveLevin]

Spoke with the owner of our local road racing track who is an AMA motorcycle road racing champion.... I asked what type of fuel do you use in the racing bikes......


his response.....

"86 octane, it adds about 3-4 HP to the engine."

It definitely depends on the engine. Fundamentally, you want to run the lowest cotane you can that prevents detonation. All the stuff to raise octane reduces the energy available in a volume of fuel. Now, practically speaking, you can get more total power from higher compression (that's why we do it!), but you want to *just* avoid detonation, and that's it. Running 110 octane in a street engine designed not to detonate on 91 octane will always result in lower hp numbers, assuming that (in use in a racecar) higher temps/heat soak don't create conditions where 91 would lead to detonation.

Steve

[Daryl DeArman]

Running 110 octane in a street engine designed not to detonate on 91 octane will always result in lower hp numbers, assuming that (in use in a racecar) higher temps/heat soak don't create conditions where 91 would lead to detonation.

Running more octane than necessary to avoid detonation doesn't help the HP. However, there are other factors (read: compounds and properties) in the fuel that lead to determining energy content. Octane does not directly correlate.

[George Dean]

Wow, What a cool discussion!! I used to believe that pump gas in a stock engine would get the job done until a few weeks ago when I was running a FB engine on my dyno and putting a pretty good load on it. I usually keep 110 octane race gas in stock but was running very low so I ran up to the gas station and bought some 92 octane (for $2.89 a gallon) I have used this same station for about 6 years now so didnt think much more about it. After doing 2 quick pulls I knew there was somthing wrong, comparing this engine with another customers engine the pump gas one made more power up to about 7000 RPM but then went very flat, I thought about it for a few minutes and thought I would run it again, Same result only worse as the engine got more temp in it the less power it would make. I went ahead and pulled the valve cover off and checked the cam timing thinking I might have missed but it was spot on, So back to the thinking process. Looking at the data the engine seemed to be fighting its self at the upper RPM range. Just as a quick test before I disassembled the engine looking for a problem I went ahead and switched to the 110 rase gas I had, The first pull was good for 12 more horse powers!!! I knew then the swamp water that I had paid $2.89 a gallon for wasnt working so good. By the way (That engine won the Seattle national congrats Phoenix race team!!) using the 110 octane gas from the track, As stated in earlier posts pump gas is great as long as you get what you pay for but it is getting more and more inconsistant all of the time, On the pumps here in Seattle there is a sticker tha say contains up to 10% ethonal, What does that mean? 1% or 6% or 9% or 0 Not too bad for a street car or bike but not so good for a racecar. Be careful you really dont know what comes out of that pump..
I guess the next question is about the designer fuels out there, Yes I have tested some fuels that have a good amount of oxygen in them and they will add 10 to 12 horse powers just by pouring them in the tank, 89 octane and cost anywhere from $25.00 to $30.00 a gallon or more!! I know as a fact that there are teams that are using fuels because I have smelled it at different tracks around the country (must be my trained nose from being inside a 12'x12' room with a running engine) A 5 to 6 percent power advantage is somthing that should be looked at for a class that was designed for stock engines and keeping cost down. As far as the health aspect of these fuels I talked to the president of VP fuels last year and he said that even though the smell will make you want to get sick the long term effects of gasolene are far worse, Its the stuff that you cant smell that will kill you,
I hope this helps a little, any of you guys can call me if you like I can talk alot faster than I type it has taken more than an hour to do this!

Good luck and I will see you guys at the track!!

George

[Dave Gomberg]

Let me add some information to what George has posted. Yesterday, someone on the Spec Racer forum raised some questions about the 100 octane unleaded fuel at Virginia International Raceway. I talked to the tech staff at Sunoco race fuels. As a result of that conversation, I posted the following on the SRF forum.

I spoke with the Sunoco race fuel tech folks. All of their unleaded race fuels, except the 260GTX, have had ethanol in the formulation since about 2004 and the amounts have not changed over that time (the 260GT is right around 9%). It appears that in various parts of the country, the ethanol labels are showing up on pumps because of local or state legal requirements.

If you are concerned about the ethanol in these fuels affecting fuel system lines or fittings, or about fuel cell degradation, pump the cell and fuel system dry if the car is going to sit for more than a few days. If you have performance or other engine concerns, you will need to use your best judgment. If you have been using the Sunoco 260GT (100) without engine problems in the past, you should be able to continue to use it.

If you want to find out where 260GT is sold (tracks and other places), see http://www.sunocoinc.com/site/Consum...T100Locations/

By the way, if you find 93 octane unleaded in track pumps, this is not a race fuel. It is ordinary Sunoco 93 octane street fuel.

We are in complete agreement that what you find at a gas station is a complete crap shoot. For one thing, even "good" companies change formulations (for good reasons) on a frequent basis. That means you simply can't count on consistent performance. Worse, are companies that toss whatever is available into their tankers and the customer be darned.

Now, with regard to what you can smell not being dangerous: sorrry George, your source is jerking you around. That's simply not true. Yes, there are things that you can't smell that are not good for you, but they are not all there is to worry about. Some of the most toxic substances that unscrupulous fuel blenders use have distinctive odors.

Dave

[RussMcB]

This is a good discussion. Thanks for chiming in, George.

The following statement is hard to believe, even considering the highly respected source:

<snip> Yes I have tested some fuels that have a good amount of oxygen in them and they will add 10 to 12 horse powers just by pouring them in the tank <snip>

Is there an explanation I would understand that would explain how that is possible? Does that special gas squeeze more fuel and oxygen into the same volume, giving some sort of super charger effect? That's the only thing I can think of ...

[George Dean]

Dave, I didnt mean to say it was not dangerous I ment to say " he said it was no more dangerous than other types of race gas" The smell dosent make it more dangerous. Thats what he said!!
I am just the messenger here. I personally have my own opinion on a fuel rule

George

[George Dean]

Yes Russ, Your engine needs to burn oxygen to run, If you increase the amount of oxygen in the volume of fuel the engine will get more power out of the same volume, Kind of like throwing newspaper on a fire

Hope this helps

George

[Dave Gomberg]

George:

First, I'm not shooting (at) the messenger - I'd never do that, particularly to you.

Second, if he meant that there are "non-smelly" fuels that are as dangerous as SOME smelly race fuels, I can agree with that. What's more, when I talk about health and safety concerns, you (all of you) must keep in mind that drinking gasoline is never going to be good for you. Whet we're trying to do is get the things that are really nasty to inhale or make skin contact with out of the fuels we use. Some are of the smelly variety and some are not. The bottom line is that a "smell test" is simply not conclusive - either way.

Dave

[Daryl DeArman]

This is a good discussion. Thanks for chiming in, George.

The following statement is hard to believe, even considering the highly respected source:Is there an explanation I would understand that would explain how that is possible? Does that special gas squeeze more fuel and oxygen into the same volume, giving some sort of super charger effect? That's the only thing I can think of ...

Another thing to remember is that the more fuel you can effectively burn the more horsepower you can make.

A given engine will supply a given amount of "air" to the combustion chamber. When the fuel brings it's own "air" or other compounds that don't require an outside source of air to burn...you can effectively burn more fuel.

To the extreme: Methanol and Nitromethane have less energy content per gallon than Gasoline. However, they can effectively be burned at much richer mixtures and therefore produce more power.

[George Dean]

Good point Daryl, And run in an engine with much higher compression ratio

George

[glenn cooper]

You can actually purchase, pretty inexpensively, a program that will take your voice and make text out of it. I think I paid $30 for one a few years ago. I never used it, I oughta send it to you. I'm sure you can come up w/ one of those Microsoft types locally that could install it for you!

The VP guy's comment sounds like something straight outta the movie "Thank You For Smoking". Uhh-huh, riiiiiiiiiiiiiiight, got it.

GC

[10rmotor]

George,

I'd think that if you ran street oxygenated fuel in a motor, and it made more power, that it was too rich to begin with at those RPM ranges that you saw an improvement. Yes/No?

[sracing]

George,

I'd think that if you ran street oxygenated fuel in a motor, and it made more power, that it was too rich to begin with at those RPM ranges that you saw an improvement. Yes/No?

Probably true to a point. In our experience on the dyno(s), most engines can be tuned to about a 13.5+:1 A/F ratio to achieve max HP. However a typical road racing engine is usually set up to about 12.8-13.2:1 A/F ratio. This allows for a little cooler burn, less chance for detonation and more safety.

Changing from a legal SCCA race gas to an oxygenated pump fuel will lean the mixture. That in itself might be the increased HP. Or possibly the breakout of the O2 molecules at the ignition point may be the adder. (Much like nitrous) Even after A/F adjustments via jetting the oxygenated pump gas seems to add some HP. Also MOST higher octane fuels have less BTU content. So with proper valve and ignition timing with the proper CR, a pump gas can always make more HP in a given engine. High octane fuels are only required for their octane (ability to resist detonation). If it weren't for that you would always want the lower octane. In any case you always want the lowest octane you can use in your engine design that can run on it without detonation.

As an example diesel contains more BTU than gasoline. However, the energy (BTU) would be wasted since it pre ignites in a gas engine.

[10rmotor]

Jim, thanks for confirming what I was thinking. Your post makes total sense.

I don't recall who posted above that they have been running pump for some time and never failed a test. I gotta call BS on that info. Its been my understanding that the base reason for needing to run race/leaded fuel is that the testing process is not compatible with unleaded fuel. So essentially we are being forced to run leaded high octane fuel merely because of an inadequate testing procedure. As George (THE MAN) and others have said, premium pump gas is perfectly fine for a STOCK bike motor that all you FB guys use. Since we are forced to use leaded, and because DSR rules allow engine modding, shaving the head and using high compression pistons at least exploits the higher octane requirement.

At least the leaded fuel is good for the valve seats.

[sracing]

Jim, thanks for confirming what I was thinking. Your post makes total sense.
I don't recall who posted above that they have been running pump for some time and never failed a test. I gotta call BS on that info.

Yep. A bit hard to believe. Straight pump fuel will NOT pass an SCCA test.

Its been my understanding that the base reason for needing to run race/leaded fuel is that the testing process is not compatible with unleaded fuel. So essentially we are being forced to run leaded high octane fuel merely because of an inadequate testing procedure.

Exactly.

[RussMcB]

Straight pump fuel will NOT pass an SCCA test.

Are you sure? I have never had my straight pump gas tested, but I'm pretty sure the FB rules allow it.

10rmotor, thanks for asking your question. I was thinking the same thing (that the engine must not have been tuned optimally if it made a lot more HP just by using a different fuel).

[Dave Gomberg]

It gets a bit old answering the same questions over and over. Please see post #6 in this thread (first page).

Dave

[Daryl DeArman]

You can lead a horse to water.....