Abstract |
The present nine-mode FTP defines power points in terms of manifold vacuum. However, with the advent of supercharged, turbocharged engines, and other advanced emission control systems, manifold vacuum can no longer be used as the sole parameter in defining an engine's power points. It would be desirable to redefine the nine-mode FTP power points in terms of percent torque or power. This redefinition is expected to alleviate problems encountered from engine to engine variation in manifold vacuum versus horsepower (torque) relationships. The new nine-mode test procedure would then be similar to the method used by the 13-mode diesel procedure. As a basis for the conversion to percent of load from the manifold vacuum test points currently in use, data from nineteen engines used in past contractual work were used. Linear regressions were performed on each set of data for each engine. |