I was thinking of getting a dump valve for my Seat Leon Cupra 180bhp, I was told that it doesnt sound good and it is pointless. Any ideas or suggestions. true or false: The valve on the car now leeks and is a common fault with the car.so it is really running at about 155bhp.so when you fit a dump valve the ecu picks it up as a leek and slows the presure of the gas causing a swoosh not whoosh.A seat mechinic said to get round it is to use a powertec st/st induction kit which will echo the sound and change the valve to a recirculating valve getting the closest to a sound you want to here. This should regain the lost break by tricking the ecu. please help This does not happenen on cupra r.