Kelford Valve Springs and Retainers for 4G63 DSM/Evo (KVS63-BTK-X) Prothane The Wideband O2 air/fuel ratio

The Wideband O2 air/fuel ratio UEGO gauge is a must if you want to maximize your engine's power and safety

Let the car run until it starts to stumble

The adjustment range provided by the eccentric washer on the OEM control arm is insufficient to get camber back into proper spec

2013+ Scion FR-S

Kelford Valve Springs and Retainers for 4G63 DSM/Evo (KVS63-BTK-X) Prothane The Wideband O2 air/fuel ratioKelford racing high performance, premium quality PACALOY beehive spring and titanium retainer set fits all 4G63 Evo, DSM and GVR4 models. Suits high RPM, high boost competition engines. Install at 90lb. Maximum valve lift is 13. 50mm. This BTK X has the addition of springs being treated with a nitrate finish. Vehicle Fitment: Mitsubishi 4G63 Turbo 1992 2006 Evolution I IX 1990 1999 Eclipse GST GSX 1990 1998 Talon TSi 1990 1994 Laser RS 1991 1992