My question is this.
Does the secondary injectors open at 3500 rpms by the ecu, or does it need something else to make it open such as the 5th 6th ports.

Why I ask this is because my 5th/6th ports open a little early at around 3k and I dont want to waste gas if the secondary injectors rely on the ports, since I shift at around 3k at normal temps.

 

Nope, they come on at exactly 3800 RPM, controlled by the ECU.

 

The injectors are comtrolled by the ecu.
The aux ports are controlled by either the
air pump(on an S5) or the cat (on an S4).

 

thx guys