Patent ID: 7225787
Filing Date: 2007-06-05
Classification: F02B,F02D,F02M,Y02T

Abstract:
1. A turbocharged, high compression ratio, spark ignition engine which uses port fuel injection of gasoline from a first source in addition to direct injection of E 85 from a second source comprising: a spark ignition engine with a compression ratio of 11 or greater; a turbocharger; means for port fuel injection of gasoline from the first source; means for direct injection of liquid E 85 from the second source; wherein during part of engine operating time, the engine is powered both by gasoline that is port fuel injected and E 85 that is directly injected; and where under some operating conditions the instantaneous energy ratio of ethanol to total fuel is at least 20%; and wherein the E 85 is directly injected in such an amount that the fuel octane number is enhanced by at least 20 octane numbers relative to that of port fueled gasoline alone, and a means for direct fuel injection of gasoline; a fuel management system including a microprocessor for increasing the E 85/gasoline ratio in the engine to an amount sufficient to prevent knock as the turbocharger increases the manifold pressure; and the fuel management system uses the combination of open loop control with a look up table and closed loop control with information from a knock sensor to vary the E 85/gasoline ratio; and wherein the fuel management system minimizes the amount of the E 85 by determining when and how much E 85 must be used to prevent knock as the manifold pressure is increased by using a knock sensor and further wherein: the fuel management system controls the amount of air to the turbocharger, the amount of gasoline and the amount of the E 85 to obtain a substantially stoichiometric air/fuel ratio during all or part of the time that the ethanol is injected based on information from the knock sensor, an oxygen sensor and a look up table thereby enabling use of a three way catalyst; and wherein gasoline is directly injected if there is no E 85 in the second source; and where when no ethanol is used and the gasoline is directly injected the vehicle is operated at higher loads than is the case when it is operated with port fuel injection of gasoline alone; wherein the amount of E 85 in the second source is used as an input to the fuel system microprocessor to control the level of turbocharging and: wherein the turbocharging is reduced or eliminated when there is no E 85 in the second source; and wherein the turbocharger is adjusted so as to prevent knock; and wherein the spark retard is increased when there is no E 85 in the second source; wherein the amount of E 85 in the second source is used as an input to the fuel system microprocessor to control spark retard; and wherein the E 85 consumption from the second source is reduced by reducing the maximum level of turbocharging that is allowed or by eliminating the use of turbocharging; and wherein a driver can determine the maximum level of turbocharging; and wherein a tradeoff between the E 85/gasoline consumption ratio and the maximum torque and horsepower can be accomplished; wherein the engine can be operated on more E 85 than is needed to prevent knock; and wherein the engine can be operated solely on E 85; and wherein a greater amount of gasoline than would ordinarily be used is employed to facilitate startup during the first 30 seconds of engine operation; and wherein the first and second sources are separate compartments in one fuel tank; and wherein the engine can also be operated on denatured ethanol which is provided to the second source by containers; and wherein when the ethanol is directly injected the engine provides the same horsepower and operates with at least 20% more efficiency than would be the case if it had at least twice the cylinder volume and operated with port fuel injected gasoline alone.