Originally Posted by davidnormanuk
Why do cosworths run a DV from standard then even though they are running standard boost. To me it makes sense to use one wether its a recirculating one so you don't get the noise or a normal one.
because they use MAF sensors, and without the dump valve, the charge travels back down the wrong way causing it to come off the throttle very abruptly.
The MAF sensor senses air flow, but not in which direction it flows. Same story with all forced induction cars with MAF sensors
