i was wondering on your ideas on how to do this.
i have 2 rpm activated switches from summit that i was going to hook up to the vacume selenoids but i hear that the vacume is created by the air pump. now what happens if i remove the air pump?
can i find other vacuume sourses on the motor?
would this be ok?
what rpm should i have the ports open and how bout the VDI?
does this change depending on the mods done to the car?

its a 90 motor that i'm putting in my 87 so my ecu does not even know they exist. i need to find a way (other than wiring them oped) to open them

no cats
K&N intake
TB mod

thanks
bill

 

they should start to open around 4k rpm. actually it's not vacuum that opens them it's positive pressure (about 2 psi exhaust back pressure, or depending on the year air pump pressure).