Crate motor racers have a...
Crate motor racers have a unique set of demands for their race fuel. Pump gas simply isn’t consistent enough and can cause problems keeping the engine operating at peak power from one race to the next. But traditional race fuels aren’t blended with these low-compression, low-rpm motors in mind. The solution for many is new blends of race fuel designed specifically for this unique engine package.
It’s no secret that every component on a race car has a useful lifespan. Even if there is no wreck, most—like the frame and suspension components—will fatigue and crack over time simply from the stresses of racing, but can last for years with regular maintenance. Other components, like the pistons, valves, and wheel bearings, can only make it a season or less before requiring replacement. A third category, such as your seatbelts and window net, are on a clock as soon as they are manufactured and must be replaced by a certain date regardless of how many laps are on them.
And then there are the consumables. That’s the stuff like tires, fuel, oils, and other lubricants, and even the tear-offs that must be replaced practically every race. Many racers consider the cost of consumables little more than an expense similar to pit passes, drinks for the cooler, and the diesel burned to haul to the racetrack.
But how many of us really consider the racing fuel we burn as a tool that can help us gain a competitive advantage. Steve Burns, VP Racing Fuels’ founder, says that the right race fuel combined with an engine that’s properly tuned to that fuel can be precisely that—an advantage over the competition.
One of VP’s newest race fuels is called “CHP,” which stands for crate horsepower. With the ever growing popularity of crate engines in circle track racing you knew this was coming. But Burns says that CHP is much more than a marketing gimmick. It has actually been shown to make gains of 15 to 20 horsepower or more over pump gas and is also better suited to low compression crate motors than traditional race fuels like VP’s C12.
But if the most common crate motors—GM’s 602 and 604 offerings—are little more than standard truck motors fitted with a single-plane intake and a circle track oil pan, then how can a race fuel make any difference?
“There are a lot of advantages CHP has over pump gas,” explains Burns. “Can we make a fuel that makes more power than pump gas? You bet, but that’s no big deal. Our competitors can do that. Just making more power than pump gas doesn’t really separate us from the pack.
“It’s the things we can do beyond that that makes this fuel a big deal,” he continues. “Not only can we formulate a fuel that makes more power, but we can also make it so that the engine is more easily tuneable with better throttle control. We can make it so that it’s the same every time you buy it so that it doesn’t throw off your tuning. And we can even make it so that it’s easy to tech so it’s easier for track officials to catch any cheaters that are making your life more difficult.”
The obvious reason that crate racers might prefer to fuel their cars with pump gas is obviously because it’s cheaper than practically any race gas out there. Since the crates are low-compression motors and there is little chance of detonation, the thinking goes that there is little advantage in paying extra for race fuel.
VP Racing Fuels found Steve...
VP Racing Fuels found Steve Burns analyzes fuel formulas to determine if they will deliver the performance characteristics desired. VP’s fuel blends are very specific in their intended uses in order to maximize efficiency and power in the race engine.
“There’s no doubt that pump gas is going to be cheaper than your race fuels,” Burns explains. “But there is one thing I can tell you: All pump fuels are made to the cheapest possible specification. Gasoline is the highest traded commodity in the world. We move it around in multi-million gallon barges. And then we pump it through a pipeline that’s two or three feet in diameter with it moving seven or eight miles an hour. With that kind of volume of oil and fuel moving around, if you’re off by two or three cents a gallon you’re done. You won’t sell any of it.
“So is the gasoline the same every time you pull to the pumps? Most certainly not. Most people get their gas from a station, and the station got it from a truck, which got it from a big tank. That tank was probably filled by a pipeline, and who was feeding that pipeline that day? Who knows, it was probably whoever offered the best deal. So you just can’t have consistent pump gas. Not only do different companies have different formulations and blends, but they can even vary depending on the season or the price of the components that go into the blend. That’s fine for my Suburban, and it’s fine for most of the cars that are running around on the roads, but that’s not fine for your race car.”
The key difference between a race engine and a motor in a street car is that the race engine is always operating at maximum effort. The street engine, meanwhile, spends the majority of its working life barely above idle. Modern computer management systems and electronic fuel injection allows the street motor to adapt to variables in the fuel it’s fed, and even then the driver isn’t likely to notice small changes in the horsepower or torque available. But a carbureted circle track racing engine must be tuned manually, so any changes in the fuel must be dealt with by physically retuning the engine by adjusting such things as the carburetor’s jets, power valve, or even the squirters, and possibly resetting the timing. And because we’re always pushing the engines to produce maximum power, any changes in output not only can be noticed by the driver but can also have a real effect on the final standings.
“So even though the fuel has the same brand name and the same octane rating, there are two big things that can vary from one batch to the next,” Burns continues. “The first is specific gravity (which is the weight of the fuel relative to water at 60 degrees F). All the materials that go into the blends can cause the specific gravity to vary if you aren’t careful. And that can affect how the fuel behaves in the carburetor. If you have something that weighs 100 pounds per gallon then it will go through the jets pretty easily. But if you have a liquid that’s as light as helium, there’s no way you’re going to get it through the same jet. Now, I know that’s a pretty ridiculous example, but at least you get the idea. Specific gravity affects how you will tune the carburetor for best performance, and if that changes on you then, obviously, you’re no longer going to have the optimum setup for power and throttle response. At VP we give you the specific gravity for all of our circle track racing fuels, and we make sure it stays the same, time after time, season after season.
Burns looks on as Chief Chemist...
Burns looks on as Chief Chemist Duane Minazzi uses a gas chromatograph to verify blended fuels contain the correct composition prior to drumming and shipping.
“The second factor is what you might call the ‘effective octane.’ The octane rating label may be the same, but the way the fuel actually acts in a running race engine can be quite different. You can have 92 octane in your race engine that because you have a cool intake manifold—where a street engine usually has a hot intake manifold—you can easily see two and three octane numbers difference. And that can really affect your performance,” Burns says.
“What you have to worry about is the light materials in the fuel blend that vaporize easily. And when they are vaporized they will also blow up more easily. That vaporization is more likely to happen in a racing engine, and what you wind up with is a lower octane fuel.
“So what you have is different effective octanes. Maybe you have wondered sometimes you seem to pick up a little detonation and the engine is running hotter than normal. Well, it may not be your cooling system or the engine itself, it may be that you’re running a different fuel blend with a lower effective octane and didn’t know it. So you were getting by fine before but now because of the differences in the pump gas you’re using, this tank isn’t working so well.
“With a lot of our fuels at VP, we actually blend them so that they act like they have a higher octane than what’s listed,” Burns continues. “If you look at our C12 fuel, the octane we list for that is 108 but it actually acts like a higher octane than that. We’ve run it very successfully in applications that logically it should never have been in. But it vaporizes well and the stuff that does vaporize is very resistant to detonation. There are no real radical guys in there that want to blow up unexpectedly. That’s what you have to watch out for: the stuff that vaporizes and then explodes before the spark plug fires and that, in turn, detonates the entire fuel load.”
Tuning Your Fuel to Your Application
Minazzi, uses coulemetric...
Minazzi, uses coulemetric titration to detect the presence of water in solution, an important test particularly for oxygenates introduced to fuel blends.
OK, so it’s obvious that spending a few extra bucks for race fuel instead of filling your fuel jugs at the local Gas-N-Go can be beneficial both in terms of horsepower, tuneability, detonation protection, and even throttle response. But then there’s the other end of the spectrum. If you take a look at the available offerings for circle track racers just on the VP Racing Fuels website, the number of options available can quickly become a bit intimidating. And that’s not even counting all the other racing fuel manufacturers out there.
But that’s OK because Burns says that’s what the tech department is there for. Freddie Turza is the R&D Director at VP and says he also spends a lot of time helping racers not only find the perfect fuel blend for their needs but also tune their engines to make the most of that fuel.
“The reason we have all these different fuel blends is because different engine packages may require different things,” Turza explains. “For example, let’s stick with the crate motor racers. I’ve had this happen several times where a crate racer will run the track fuel. It’s usually either a 110-octane race fuel or our C12 which is 112-octane and one of our bedrock racing fuels. C12 is a great fuel for a lot of different applications, but it isn’t designed to suit the needs of crate racers.
This is VP’s testing lab used...
This is VP’s testing lab used to determine the octane ratings for its fuels. Most fuels are rated for both a “Motor Octane Racing” and a “Research Octane Rating.” Racers should always check for the Motor Octane because the testing for that rating mostly closely relates to the stresses a racing engine places on the fuel it burns.
“So the crate guy will come up to me and say that he runs better with pump gas than the track fuel. And the fact is that the track fuel may be a little too high grade for his needs. The fuel is designed for a high-compression, high rpm motor, and burns just a little too slow for the needs of that crate.
“But when I can turn him on to a fuel designed for his motor like the CHP, then it really becomes obvious to him that the pump gas really isn’t the best option either. The CHP is blended specifically for the crate motor, and the octane and vaporization rate is dialed in to work with it.
“With the Chevy 602 crate motor I’ve seen gains as much as 23 lb-ft of torque and 25 horsepower. By switching to CHP the average guy will see 16 to 18 horsepower and 12 to 15 lb-ft of torque. And with those limited horsepower crate motors that kind of gain is quite an improvement.
“The key,” Turza continues, “is getting the engine tuned to work as well as possible with the fuel. Then, because the fuel is so stable you don’t have to worry, the performance will be the same night after night. Usually, we will start with a major jet change when switching to CHP for the first time. With a 600 Holley carb we will increase the jets about six sizes all the way around. Then we will make some power pulls on the dyno until we achieve maximum torque and horsepower. We’ll just keep putting fuel to it until the power plateaus off.
VP provides trackside fuel...
VP provides trackside fuel service for nearly 200 race events of various types each year. If your track only carries one type of fuel and it’sn’t the fuel you need, VP can ship you fuel in barrels that is guaranteed consistent from one batch to the next.
“Now we know the engine is making good power, so it’s time to put it in the car and see what it has got and tune for driveability. On the track we are looking to tune the engine to give the driver the best throttle response possible so that he can really drive the thing. That may require a little work with the squirter or the low speed settings on the carburetor.”
Interestingly, Turza says that much of his work with racers and teams isn’t talking specifically about different fuels, but rather on engine tuning. “Because of the growing popularity of the crate classes,” he says, “many of these racers have alienated themselves from the engine builders. Engine builders have always been the resource when it comes to helping racers maintain and tune their engines and carburetors. But engine builders help their customers, not those that are buying crates. Because of that we’ve stepped up our role to help these guys out. I don’t mind helping a racer however I can with any problem he’s got with his car. And because a lot of the crate racers are new to racing, the questions we get can be all over the place. A lot of times when I’m helping somebody I’ll get a call from him every week for a month until he gets his engine tuned so that he’s getting good performance and great throttle response, and then once he gets things nailed down I won’t hear from him again.”