a lot different with the stock valves on. It was curious to see the difference in flow through the MAS air sensor. With the RFL BOV's on I noticed that the air reading did not decrease much when I shift which would mean that the BOV's are doing what they are supposed to be doing. With the factory ones in the readings decrease rapidly to a near zero state when shifting. That makes sence to. It would be nice have the best of both setups.