turbo 6 bangers post here

The main idea for the crutch system is so that you can use small jets to have a cleaner cruise and lean on the T-brake or stall but once the RPM activation to the pump or whatever you choose to send signal to the BRPV's, they will act as a secondary set of jets to allow extra fuel into the engine that the small jets cannot do alone. Once a run is complete, the air system will shut off and the carb will run off the normal smaller jets again. You can activate the PV's several diffferent ways like using a mini air pump with some type of controller such as the MSD8969 RPM controller or even thru your MSD7531 unit im useing a pressure switch kind of like a Hobbs switch and using hat psi to activate the air pump. Doing this type of set up gives you PV's opening control from the cockpit instead of taking the carb apart to adjust or replace springs.