In this episode of Speed Secrets, Richard Holdener explains everything you need to know about E85, and puts the ethanol fuel blend to the test.
There are many benefits to running E85 fuel, which is a blend of 85% ethanol and 15% gas. It is a much higher octane fuel (112 vs 91) than what is available at most pumps, yet less expensive than pump gas. Because it is alcohol based, it also has a lower charge temperature than gasoline, which can improve power. To explore the benefits of running E85 versus gasoline in race applications, Richard Holdener from Speed Secrets teamed up with Comp Cams.
Richard starts with a naturally aspirated 6.0L LS engine with a hearty Comp cam (part number 54-469-11) with a .617/.624 lift, 231/247 duration and a lobe separation angle of 113. He then adds a Fast XFI ECU management system and Fast coil packs. To control the experiment and make sure any gains seen would be from the fuel used only and not a difference in tune, the ECU is tuned to maximize power output for each fuel used.
The first dyno run for the 6.0L, using 91 octane fuel put down some pretty incredible numbers as did the same 6.0L running on E85. In fact, the differences in the two fuels used were negligible. Richard then added a few degrees of timing to the engine hoping to change the results, but again there was not much difference.
To further test the fuels, Richard then added an intercooled turbo system to the same 6.0L engine. Using 114 octane race gas first and then E85, he dyno tested the engine again. On this set up, running E85 produced big gains over using 114 octane race gas. Unlike the negligible results obtained before, on the turbo setup, E85 made a 45-50 horsepower difference, proving that on the right setup, the fuel does offer a big incentive.