Conversion of a 1999 Silverado to Dedicated E85 with Emphasis on Cold Start and Cold Driveability

The University of Texas Ethanol Vehicle Challenge team focused upon cold start/driveability, fuel economy, and emissions reduction for our 1999 Ethanol Vehicle Challenge entry. We replaced or coated all fuel system components that were not ethanol compatible. We used the stock PCM for all control functions except control of a novel cold-start system our team designed. The primary modifications for improved emissions control involved ceramic coating of the exhaust manifolds, use of close-coupled ethanol-specific catalysts, increased EGR for the operating conditions of the five longest cruises on the FTP, and our cold-start system that eliminates the need to overfuel the engine at the beginning of the FTP. This EGR control scheme should also benefit urban fuel economy. Additionally, we eliminated EGR at high load to improve power density. Major modifications, such as increasing the compression ratio or pressure boosting, were eliminated from consideration due to cost, complexity, reliability, or emissions penalties. Our major effort was aimed at developing a unique solution to the cold start and cold driveability problems associated with E85.