Z1 just released their rotrex supercharger kit and although the fit and finish looks amazing, I can't really comment on their numbers. At 10psi they require E85 to push 395wtq, the Topgunz kit can easily push 450wtq at 10 psi on 91/93 fuel. The Topgunz kit is superior in that regard, I'm not sure if they were more conservative to get it CARB approved in the future but it seems to be track tested so cooling appears to be dialed in.
https://www.z1motorsports.com/superc...b44c1df4d30a20