Why the GReddy BCC?
The reason that the MkIV owners recommend the GReddy BCC over the HKS Fuel Cut Defensor (FCD)and the Free Fuel Cut Defensor (FFCD) is simple. The HKS unit reduces the signal coming from the turbo pressure sensor at a fixed percentage, which means that all the data coming from this sensor is corrupt. The FFCD fixes the value coming from the turbo pressure sensor at something close to atmospheric by capping the pressure input to the sensor. The turbo pressure sensor is used for six different functions by the ECU. The most noticeable is fuel cut for an overpressure condition which is 2.00 kg/cm2 absolute pressure, or 0.97 kg/cm2 gauge (28.45 psia, 13.75 psig). Fuel cut is an extreme measure invoked by the ECU when it detects boost over 2.00 kg/cm2 absolute, AND throttle position 20 degrees or more AND engine speed over 2400 rpm. It shuts down the engine until the boost drops back below the 2.00 kg/cm2 threshold, and lights up your MIL (malfunction indicator light). The other turbo pressur
