Did you enrich the fuel via the EHA valve? I'm running an ATI Procharger and around 10 psi in my CIS-E 560 SEC. I know for a fact that the 560's CIS will flow over 400 hp. I have my EHA turned 8 turns clockwise to compensate for the extra air. Since the addition of a larger diameter crank pulley and a smaller diameter blower pulley, I've been running lean on fuel at around 5,000 rpm.

My last dyno run was 346 RWHP and 404 RWTQ on a dynojet. I've added the cog pulley system and an air to air intercooler since. I'm now spinning the ATI Procharger P1SC blower at 62,000 rpm. I'd estimate I'm close to 500 hp with my CIS. However, the CIS is the limiting factor to more horsepower gains so I'm looking at switching to an aftermarket EFI system.