These cams are suitable for street-driven engines, offering improved mid-range power compared to OEM cams on turbo applications, while maintaining good drivability. Kelford Cams recommends the KVS109-3S valve spring upgrade for 262ø cams designed for 3S-GTE engines with OEM or upgraded turbos sized between 48-54mm and producing 400 horsepower. They also perform well with E85 fuel.