Thanks for the kudos Dave!

I agree completely with your statements about fueling. The fuel requirements of today are not the same as your grandfather's Chevrolet.

Mayhem was a bit of a challenge with the dual ZL1 fuel modules, but the use of a Hobb's switch to control when the second fuel module is activated (still using PWM) cured some of the hurdles. The VaporWorx control system can handle three ZL1 fuel modules @ 100% DC from a power standpoint, so if you really want to crank it up......

Another method to control the relay would be to use the output from an aftermarket ECM that sent a signal at a specific MAP setting. This would work for aftermarket ECM's. I don't believe GM ECM's have this capability.