Huge horsepower will never go out of style, but the tools, vehicles and fuels used to make that power will always change. Thanks to environmentally-conscious motorists looking for an alternative to petrolium-based fuels, E85, 85% corn-based ethanol and 15% gasoline blend, is becoming more common. In addition to being somewhat more environmentally friendly, E85 is also 105 octane which is great for making big power and lots of boost. The downside to E85 is that it is about 1/3 lighter than gasoline and requires more fuel to be injected into the combustion chamber than gasoline. That means upgrading your fuel system in a way not needed for gasoline applications. This car, a 2007 STI limited, was built for a COBB Tuning Surgeline customer who wanted to make as close to 600whp as he could, using E85 as his fuel of choice.

To provide the needed fuel to run a STI complete with a GT35R turbocharger and GSC Stage 2 cams, A single Walbro fuel pump feeds a COBB Tuning Surgeline custom-built surge tank. Feeding fuel to the engine is a pair of Bosch 044 inline fuel pumps that lead to a set of Injector Dynamics 2000cc injectors. While this may seem like a little overkill on the fuel system side of things, keep in mind that E85 dictates a very large volume of fuel to compensate for the large amounts of boost this car was setup to run. Peak power of 547whp was made at 27lbs of boost! On 92 octane pump fuel, power was limited to only 454hp, E85 allowed this engine to run 5psi more and an extra 100hp!

Vehicles tuned on E85 are quickly becoming more and more popular. Not for their supposed eco-friendly nature, but due to their ability to greatly increase horsepower while still being a relatively inexpensive fuel source compared to leaded, and even unleaded “race” fuels. For more information on how to setup your car for E85 power, contact COBB Tuning Surgeline today!