The 1999 Miata uses a modified BP, the BP-4W, which replaces the old Hall Effect dual Cam Angle Sensor unit mounted at the back of the exhaust cam with two separate Hall Effect units at the front - one on the intake cam gear and one mounted on the oil pump, to the side of the crankshaft pulley. It also has an improved intake system (a better flowing cylinder head because of the angle of the intake ports being changed). There was also a switch from the earlier problematic hydralic lifters to solid lifters. The United States 2004-2005 Mazdaspeed MX-5 turbo is based on this engine rather than the newer BP-Z3 and produces 178 hp (133 kW) and 166 lb·ft (225 N·m) with slightly reduced compression. The Mazdaspeed turbo engine has no VICS, but does have VTCS which is often mistaken to be related to VICS.
Applications:
- 1999-2000 Mazda MX-5/Miata
- 2004-2005 Mazdaspeed MX-5 (turbo)
Read more about this topic: Mazda B Engine