hard to say how much power, its definelty the biggest increase i've felt out of any mod by far! guessing at least 20RWKW but the top end is so happy when u get there its really hard to estimate. yeah no issues with the VCM one, not to sure on the max airflow reading, would be nice to see. steve said its up 10-13% before the tuning. almost feels like your hitting boost at times just with how much it wants to go! haha