RomRaider

I have a 2004 WRX that runs a 02 ECU and the carberry rom that I use for Rally X at a novice level. I am currently using the throttle bypass style ALS native to carberry but have been daydreaming of Fresh Air style system utilizing Turbosmarts ALV40 valve. If anyone has any advice or can confirm my control theory that would be amazing.

Traditionally the ALV valve would have a solenoid that opens or closes based on its own duty cycle table that would look a lot like the IACV table in carberry. One train of thought is to have an addition to the program made that mimics the IACV map and outputs to an unused output like the ECV valve to control vacuum to the valve similar to a wastegate. This is however outside of my reach of capability to make custom logic as described. Option two would be to use the current control to get the needed extra fuel with the timing and fuel control. I can set the IACV duty cycle back to normal so that manifold vacuum would still be present until the throttle was opened. I would then have an on off switch that would open a solenoid allowing manifold vacuum to open the ALV40 valve. This would be toggled the same time as using the defogger switch to enable carberrys antilag. In this scenario if the car was under vacuum then the ALS valve would be open and the extra fuel would be added to the system allowing pressure to be created upstream of the throttle body. Once the throttle was opened pressure would be introduced to the manifold closing the ALV valve and giving that instant boost response. Is it that easy?

I have a few theories to limit achievable off throttle pressure if fuel alone doesn't have the granularity. Both would be via manual boost controller that either sends pressure to the ALV valve negating the vacuum required to open or sending pressure to the wastegate to bypass the turbo once the system upstream of the throttle is pressurized. Lets see if either of the above are achievable first though before I wrap my head around that piece.

Any commentary or direction to further reading is very welcome!

i think you're going to struggle to get the standard ecu to play ball with your plans here. if your at a stage where you need fresh air ALS it may be better to look into an aftermarket ECU that would control the ALV40 valve as well as switch the mapping around when the valve is active.

You might be able to play with the map switching though to add fuel/mess with timing when the valve is open (some kind of relay configuration to trigger the valve as open when your off throttle as well as trigger the map switch until you touch the pedal again then valve closes and ecu returns to map 1).

Ha yaaaaaa this would certainly be much easier with a standalone however not quite in the budget for this car. Especially not at the rate ive been going through tires. I still feel like for the conditions and options in Carberry I would have enough motor control to make this usable I just cant wrap my head around how to control the actual valve.

I like your idea of the relay. It would be easy enough to to make a throttle switch that could drive the relay off and on when throttle is closed to activate opening the valve. There is even electric only (solenoid driven) option of the ALV40 that would mean no pneumatic would be needed.

Assuming just opening and closing the valve off manifold vacuum wouldn't work what about driving a solenoid off of the existing IACV circuit? Already used in the Carberry Throttle Bypass Anti Lag.

I have actually just had the thought of using the water meth injection logic to run the fresh air valve. Looking at the available tables it looks like it could be made to work.