bobkingfish
Full member
Hello, i have a 2019 Hyundai Elantra se 2.0 automatic. unrestricted the intake system one end to the other up to the throttle body. Had the throttle body bored from 60mm to 64mm flat sided the throttle shaft and ported the opening very much. exhaust is about 1.9 inch o.d. how big should i go with cat back for max power and mileage, thank you.