NASCAR crews will soon be filling up with a different fuel
(Photo: NASCAR/Autostock)
In addition, NASCAR, Sunoco and engine builders plan to work with the ARCA Re/Max Series at Talladega Superspeedway to study the use of unleaded fuel in engines with restrictor plates. If all goes well, NASCAR plans to mandate the use of unleaded fuel in all three of its national series, including Nextel Cup, by February 2007, a full year earlier than required by the 1970 Clean Air Act.
A painless fuel switch expected Moving to unleaded fuel was planned for several years, but it was due to advances in coating technology that NASCAR finally mandated the change. When first announced, many engine builders were concerned about losing the natural lubrication that leaded fuel provides, but teams have found suitable substitutes. Several engine makers have gone on record saying that the accelerated timetable for unleaded fuel won't cause any major problems. "It was not as bad as we thought it was going to be. There is a lot of coating process stuff out there," says Danny Lawrence, an engine builder for Richard Childress Racing (RCR) since 1985. "It is going to be one of those things where if you just coat the valves and some of the parts, and if you don't have excessive wear, it is not going to be bad at all." Doug Yates, head engine builder for Yates Racng added, "It [coating advances] was not readily available before, but now, I don't think it's going to be a very hard transition," Yates says. "There are some coatings that you apply to the valves. The valve seat recession was the biggest problem, and I think that we can overcome that pretty easily."
Clean air goes trackside The 1970 Clean Air Act - which mandates the elimination of the use of leaded gasoline in machines like airplanes, tractors and racecars - requires NASCAR to comply by the 2008 deadline, but the racing organization hopes to be ready a year early. "We've been back and forth to the drawing board for several years to find an unleaded fuel that is compatible with NASCAR engines," says Gary Nelson, NASCAR's vice president of research and development. He adds that NASCAR began reviewing possible alternative fuels as far back as the mid-1990s, but each caused engine problems - including engine failure - until the new Sunoco blend was developed. A partnership between NASCAR, its fuel supplier Sunoco and the U.S. Environmental Protection Agency (EPA) resulted in the development of a special unleaded blend. Sunoco 260 GTX not only meets EPA requirements but also performs well in engines. Nelson added that that the blend has been undergoing research, development and testing at the NASCAR Research & Development Center in Concord, NC, as well as in several junior racing series such as the ARCA Re/Max and Grand American series. Lawrence agreed that engine builders had experienced problems adjusting the power levels in the motors with previous unleaded blends but that these problems had been alleviated by the newer blend.
Change is rarely simple ... Traditionally, racing engines have required a high-octane fuel to control the timing of fuel detonation and enable a smoother running engine, within a high horsepower, high compression and high engine RPM environment. Lead in regular racing gasoline blends helps boost octane and adds lubricity, particularly in the valvetrain. It was only when NASCAR decided a few years ago to lower the engine compression ratio and revise the gear rules to lower the RPMs of the engines that a switch to unleaded fuel was feasible from a performance perspective. NASCAR and individual team dynamometer tests have shown there has been a negligible drop-off in horsepower with the new fuel. Sunoco reports it has solved the detonation issue with a complex mix of fuel additives. The specialty coatings developed for valve faces address the lubrication problem, but lengthen the engine building process by two weeks. Given that races occur nearly every weekend during a season, that extended engine building process will require teams to make lead-time adjustments.
Sunoco 260 GTX
Race Fuel SpecsFuel propertyTypical specificationsSpecific Gravity0.763Antiknock Index (R+M)/298RON, Research Octane104MON, Motor Octane94Reid Vapor Pressure5.9Distillation
