Variable Intake Runners (QR25DE)
Has anybody tried modifiying the VIAS yet? I've been looking at the wiring diagrams. I'm wondering if I can make a control box to adjust where the runners switch, instead of the stock 5000 rpm switchover point. I'm thinking there may be more power to be gained.
Looking at the wiring diagrams, the VIAS control box has one wire fed into it from the ECU. At RPMs under 5000 rpm, the wire sends battery voltage to teh VIAS. This causes to the VIAS to block of the vacuum signal to the power actuator, and the shorter runners are closed. At rpms above 5000 rpm, the ecu sends a voltage signal to the VIAS of less than 1 V. This causes the VIAS to open, creating vacuum to the power actuator, thus switching the intake runners to the shorter runners.
Is it possible to make a control box where I can adjust the switchover point? I figure I can have an incoming signal from the tach, which is measured in voltage. Another wire coming in would be battery power. A third wire coming in could be the low voltage signal, (probably tap into the upper O2 sensor since it is always between 0 and 1 V). Coming out of the box would be one wire, that would go to the VIAS. The box would be a switch with a variable switch point on it. The switch point would simply be adjusting the voltage at which it switches (tach wire). It would send either the signal from the battery voltage, or the O2 voltage depending on the rpm.
Does this seem feasible? I'd like to hear of opinions on this. Or if somebody has succesfully done this, how you did it.