HKS ETC and HKS EDA for BNR32
The HKS Electronic Torque Split Controller (HKS ETC) allows you to lock the hydraulic ram mechanism at different extended lengths in the transfer case to go all the way from locked 50/50 f/r split, to 0/100 f/r split with several in-between adjustments.
The HKS Electronic Drag Adaptor (HKS EDA) interfaces with the ETC and adds a speed limiter function in so that you can run a certain lock 50/50, 60/40, 70/30, etc... and then when you hit a certain speed it switches it to full RWD mode so that you have less drivetrain loss and more power to the rear wheels for drag racing.
$600