Recirc or atmospheric s4 b9

[Chris Johnson 1]

I’ve got my S4 b9 at 423hp on a stage 1 map at the minute and I’ve heard the forge atmospheric bov and love the sound of it but was told the car needs a recirculating dump valve and if I fit the atmospheric it will be detrimental to the performance of the vehicle majorly! Has anyone on here fitted one to their b9 S4 or s5 or have any input on the two options

 

[A12RNX]

I have the atmospheric from forge no decrease in performance from what I can tell. I have managed 0-60 in 3.45s and a 1/4 of 11.64s