The split port induction stepper motor can be wired to open in 2-3 tenths of a second. The factory computer controlled setup takes a full 5 seconds to open completely, and doesn't start until the engine is above 3,500 rpm. In low gear, you'll never experience full acceleration because the transmission will shift before the high-speed / secondary runners open in the intake system. Simply remove the plug from the SPI stepper motor and connect voltage to the wires until you find which ones activate the motor. Then splice the original plug to run a secondary set of wires through a switch/button inside the car and back to the battery.

The SPI controller motor can be seen on the right side of the lower intake manifold located on the bottom right of the photograph.

Also see

• SPI intake manifolds
• Ford Escort & ZX2 section for the entire index of all Ford Escort and ZX2 related articles.