Are both pressures taken after being cooled?
I assume that the turbo pressure is taken after the air to air cooler (pressure is reduced after being cooled)
this is the custom interface that I made for the factory 401a shaker wiring.
It takes the low level output from the factory system, splits it into two rca outputs, and it also takes the factory amp (5.98 volts) remote turn on, and converts it (using a relay and the factory amplifier power...