Words: Todd Silvey
Purpose-building fuels for specific needs is something VP Racing Fuels is known for. This includes fuels blended specifically for certain engines or for particular racing applications. One of those lines is their selection of oxygenated fuels. Oxygenated fuels contain one of a variety of additives that will create oxygen molecules when the compound is broken down and becomes vaporized. There are a number of distinctly different components, some of which include ether- or ethanol-based additives.
The addition of extra oxygen in the combustion chamber allows the engine to accept more fuel. When the fuel containing the oxygenates is burned, the result should be extra power during the combustion cycle, as well as burning the existing fuel more productively. When used in the right way, oxygenated race fuel can help a race engine produce notably more power than the same engine on basic race gas.
“The efficiency comes up drastically,” says Fred Turza, Research and Development Director at VP Racing Fuels. “It also helps in the way that fuel gets distributed within the intake manifold, by evening out the air/fuel mixture.”
Don O’Neal is a racer who also represents VP Racing Fuels with his Top Sportsman Monte Carlo. He handles many relationships with VP customers, not only through his racing, but also as part of a VP fuels dealership.
“VP came out with oxygenated fuels to provide more horsepower in a gallon. I became familiar with it by using Q16 in Super Comp racing and just flat fell in love with the ability to pick up horsepower just by pouring in a different type of fuel. In working with the fuel, I saw some applications where racers were able to achieve five to 10 extra horsepower just by changing fuel. That’s horsepower that people sometimes spend a lot of money trying to find.”
Fred points out that oxygenated fuels are also useful in lower compression engines because the fuel blend helps the efficiency of the engine. “This type of fuel is going to be the most advantageous when working with a weaker combustion chamber situation,” he says. “When used in a lower compression engine, the efficiency is typically lower because of carburetor limits, intake manifold, or the intake runners themselves. So, the oxygenated fuels and their higher efficiency can help these types of engines produce more power.”
VP’s oxygenated fuel options include unleaded fuel MS109, as well as the leaded fuels including CHP, VP113, and Q16 among others. Generally speaking, an oxygenated fuel will generate the most power. With any of these fuel options, tuning adjustments will be required to optimize performance.
Q16 is recommended for use in engine applications, from naturally aspirated to nitrous to blowers, and is good for engines with compression ratios up to 17:1. “It gives excellent detonation protection so we can still be gaining some power by introducing an oxygenated fuel,” Fred says. “The oxygenates will accept nitrous well, so that makes it more powerful.”
VP Racing Fuels recently came out with X16, which has been more of a Q16 type of fuel for the budget-minded racer. “X16 is a lower cost, but it still provides additional horsepower with the oxygenate options,” Don says. “That provides an advantage to racers who are trying to build horsepower, to go as fast as they can, and yet keep engine maintenance down with less wear and tear on their engines.”
“We try to be a conservative steward of our customers’ dollars,” Don says. “The X16 costs less and for many racers, it won’t slow them down that much and still gives those performance capabilities.”
There is a laundry list of questions VP tech support asks when talking to a customer to help them choose the proper oxygenated fuel for their application. “The first thing we know is that Q16 or any other oxygenated fuel does not like a lot of inlet air temperature, so we want to know that number,” Fred says. “It’s important because oxygenated fuel wants to get to a vapor as quickly as possible. By inducing hotter air, that happens a lot sooner.”
If the fuel gets to a vapor before its time, it causes a disturbance in fuel flow. “The key to the whole objective is getting it to a vapor state at the right time,” Fred says. “So, if using a carburetor, you want it to get to that state while it is going through the booster and the venturi. In a fuel injected engine, you want it to start getting to a vapor state immediately once it is sprayed out of the injectors.”
Another number to look at is the stoichiometric mixture for a gasoline engine. The measurement refers to the ideal ratio of air to fuel that burns all of the fuel with no excess air. Most racing engines are calibrated at 14.7:1. A guy will say I’ve run Q16, but it really likes to be rich. That’s not true. He’s saying that based only off of that 14.7:1 value. C16 is a pretty powerful fuel, but switch to Q16 and the stoichiometric value is 13.6:1. So if you’re going to try to tune with an O2 sensor and run that, you’d burn that thing up.”
“The answer is we have to put more fuel to it to make the engine perform better. This is a common problem we face with racers. So when a guy says ‘I’m trying that fuel and my air fuel number is down to 12.8, that fuel likes to be run rich,’ it’s not really rich, it’s the fuel reaction. This is a number that is tough for many racers to understand.”
“It’s not a one fuel fits all type of situation with the oxygenated fuels,” Don says. “Each racer needs to evaluate their best fuel applications. That may not necessarily be one of VP’s oxygenated fuels that work best for you, but you won’t know until you do your research or talk to one of the VP Racing Fuels techs. Examining every variable aspect of your engine combination and the type of racing you’re competing will help you make your decision. The oxygenated fuels were a definite game changer for the marketplace when they came out.”
One question tech support often hears is about the percentage of oxygenates in the fuel. “The percentage depends on which additive is used, and the application for which the fuel is designed,” Fred explains. “We normally don’t like to focus on the oxygen content in our discussions with racers because they’re always saying ‘The more, the merrier’ and that’s not always true.”
Sometimes an engine application just won’t handle that type of oxygenator, and doesn’t necessarily need it. “It could be overkill,” Fred says. “The fuel system couldn’t handle that type of fuel, so their fuel system is already maxed out. Introducing a fuel with a higher percentage of oxygenate will need a minimum flow rate, meaning your flow rate has to increase with a higher level of oxygenate.”
“For illustration purposes, it’s like a chart of spark plugs,” Fred says. “That type of chart is just general to get you in the ballpark. When we publicize something that says ‘Okay you need to go up 10 percent on jets, or three or four jet numbers,’ that’s just a guideline. If everything is 100 percent accurate, then that’s what it will take. If just one thing is skewed in the fuel system, whether a fitting diameter change or needle and seat diameter change, that’s all relevant to the way the car operates and how it will run.”
VP’s tech department often hears from racers who say that they switched to an oxygenated fuel and the results weren’t as good as another racer’s results. “The fuel may react differently to that application,” Fred says. “Referring back to that spark plug example where there are so many heat ranges. A guy may think he needs a colder plug, but does it really need a colder plug or is something else wrong? Spark plugs aren’t the same, so that heat range crossover chart is just an average to get you into the ballpark, and that’s the same with fuels. It’s a guideline, and it will take much more information to get things right.”
Oxygenated fuels will require a little more care to keep from losing its effectiveness. “Any time you pop the top on a drum of fuel, you may see vapors coming out,” Fred says. “Those are ‘light end’ components such as the oxygenates. They will evaporate out quickly into the atmosphere.”
To prevent evaporation, racers need to do what they can to prevent the vapor loss. “I have guys who run C25 who don’t pour it, they force it into their fuel cells,” Fred says. “They push it right into their fuel cells using a nitrogen blanket on top of it. That may be going to the next level, but to the other extreme, a racer who uses an oxygenated fuel and leaves the cap loose or off the fuel jug can alter the fuel.”
“There is some tuning work related to how the oxygenated fuels will affect your engine,” Don says. “The off-season is a good time to work out the kinks. If a racer is looking at making a change in the program for some performance gains, it may take some time to work with timing and fuel curves related to the oxygenated fuels.”
Source: VP Racing Fuels, vpracingfuels.com