The BPU formula for the Supra will give it 400+ RWHP while your BPU formula for the Z will yeild around 400-430 crank HP...that's 320-350 RWHP. The reason is because Supra's have 530cc injectors stock and larger stock turbos... so a BPU Supra is like a stage 7 Z with 550cc injectors and T28/T25 turbos.