The next issue to address is the engine's induction. Cars and trucks that can run pure unleaded gas up to unleaded gas mixed with up to 85 percent ethanol are called flex-fuel vehicles (FFVs). From the factory their fuel-injected engines are equipped with an optical sensor (photo cell) in the fuel line that senses the presence of ethanol and enriches the fuel mixture up to 35 percent with the aid of a computer. To run E85 in a carbureted engine the jetting (fuel mixture) has to be 35 percent richer than it was for unleaded gasoline. This means a carbureted engine has to be dedicated to running E85. There have been rumors that Rochester will introduce a version of their computer-controlled Quadrajet four-barrel carburetor as part of a retrofit E85 system for older high-performance V-8s, but as we said, it's only a rumor.
The folks at Flex Fuel U.S. have announced there's hope for vehicles equipped with fuel-injected engines built after 1995. For classic trucks running a fuel-injected transplant engine, Flex Fuel U.S.'s setup promises to simplify converting an old truck into an FFV. When we spoke with Flex Fuel U.S. regarding the operating system they're using for their E85 retro-fit conversion, they explained they were in the middle of the patenting process and couldn't reveal how it works. They did mention their product is unique from existing approaches, and as soon as the patents are pending we'll have an update.
For high-performance enthusiasts as well as non, the concerns in this day and age are fuel mileage and cost. In the early years FFVs were adapted to store and burn E85 without encountering corrosion problems, but the engines weren't tuned to optimize for E85. Even with a 50 cent per gallon federal subsidy bringing E85 well below the price of regular unleaded, non-optimized engines delivering less fuel mileage cost slightly more to operate. The technology to improve E85 fuel mileage and performance since then has made major gains.
A good example comes from General Motors' Swedish subsidiary Saab. The Saab 9-5 2.0 BioPower illustrates the horsepower that can be made from an E85-optimized engine. The new Saab cranks out more horsepower and performance when it's running on E85 than on unleaded regular gasoline. The Saab's turbo motor produces 180 brake horsepower with E85, and 150 bhp on gasoline. On top of a 20 percent increase in maximum horsepower, 16 percent more torque is produced with E85 over conventional unleaded gasoline. The Saab senses the presence of E85 with an optical sensor in the fuel line that recalibrates and adjusts to accommodate the different timing characteristics and fuel/air mixture requirements. Saab says the new turbo flex-fuel engine improves fuel consumption under mid- to high-load driving because fuel enrichment for engine cooling is no longer necessary.
A new Saab probably sounds foreign to most of CCT's readers, so we will focus our story on something more pertinent to V-8-powered custom trucks, the Vanguard E85 Power Shootout held in conjunction with the Automotive Engine Rebuilders Association (AERA) 2006 RPM trade show August 30-September 1 at the Indiana Convention Center, where engine performance will be measured in three ways: horsepower, torque, and fuel consumption.