Im not sure on the Z, but I know 3 people running E85 on a STI and two EVO8's on the evo he is running 750 injectors, stock turbo and 29psi, freaking car ran 11.2 at Famoso drag strip in Bakersfield CA. with a proper tune E85 alows for a higher boost because it burns colder. With the fact that its still hard to come by here ill stick with my 91octaine and my 850 boarder kit. should have my car running again around aug. Tony