This is because the dv+ has a tougher spring to only let out as little boost as it can in order to reduce boost lag. The e92 bmw 335i with the n55 engine already sounds better than an n54 exhaust, but you can make it even more enticing by installing a dual port blow off valve (bov) by turbosmart Replace a failing bov to prevent boost leaks or upgrade.
BMW F30 320i 328i N20 / F10 520i 528i N20 - Forge Motorsport Blow Off
265 subscribers 149 35k views 6 years ago full bolt on 328i cruising and blow off valve noises
The cts turbo n20 atmospheric bov kit is made of billet construction and completely serviceable
Our kit is designed to work with all of the factory. The burger motorsports blow off valve (bov) mounts between the oe bypass solenoid and the intercooler, causing the unused charge air to vent to the atmosphere giving off the desired pssshhhh. That fluttering you hear is not just a sound.it's compressor surge and it happens when boost pressure builds up between the closed throttle plate and the spinning compressor wheel. If you don't like the sound and would rather a hiss when you pull off the throttle, install it
If you don't want either, install a wastegate concentric to your exhaust. This is because the dv+ has a tougher spring to only let out as little boost as it can in order to reduce boost lag Bov flutter is the sound of air bouncing against the turbo blades when the valve fails to open fully, whereas true compressor surge is a total airflow reversal Understanding what causes a blow off valve.
