In the course of developing a low-emission manual transmission vehicle, coast surge in the fore-and-aft direction resulting from the installation of certain emission-control devices was sometimes experienced immediately after the initiation of vehicle deceleration.Our investigation revealed that this vehicle surge was caused by combustion irregularities in a sequence of combustion-misfire-intense combustion events occurring every several cycles.A new combustibility standard. Gt/Feff, defined as the ratio of total cylinder mixture weight Gt to effective fuel weight Feff, was found to predict combustibility and irregular combustion over the entire mixture range.As a result, driveability during deceleration was improved by modifying key emission-control components.
Subscribers can view annotate, and download all of SAE's content. Learn More »