Hey guys i was just trying to better understand what a closed loop turbo system is and why i cant have a bov. I am not gonna lie i do want one more for the sound and i know that is stupid but im 16 and us 16 year olds think thats cool haha. Im going to replace my stock dv with the forge 007 and my friend said if i put a cold air intake in ill be able to hear a slight noise like i hear with his gli. Sorry for the newbie question im just trying to better understand things before i touch anything under my hood at all. BTW i have a 2004 a6 2.7t 6 speed

 

Forge Motorsport Hybrid Blow Off Valve / Diverter Valve for 1.8T Volkswagen/Audi Vehicles (Polished), Hybrid BOV/DV Valves, Forced Induction, Forge Motorsport Products & Other Performance Aftermarket Auto Parts - North American Motorsports i found this hybrid that says it works with closed loop turbo systems i wouldnt mind some feedback on it

 

The only thing I can contribute is metered air that has already gone by the mass air flow sensor will be vented to atmosphere with a blow off valve compared to a diverter valve. So bov's require a special tune from what I've read, and one that might not be ideal simply because of the metered air being vented outside of the engine. This causes the engine air/fuel ratio to change. A closed loop system is consistent in that when the diverter valve does it's job, the metered air is recirculated so the air fuel ratio doesn't change on you. There is probably more to it than that, but in a nutshell there you go.

 

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Ditto.

Connor, based on your other post, I recommend that you save some cash on maintenance/repair. A couple of grand will be gone in a single shop visit.

 

Thanks guys im just trying to get a better understanding of things so i dont end up doing something stupid

 

Correct. The MAF measured the air before it was compressed in the turbos. This air volume is used in the injector computations. If you vent this air the computer will think there is more air in the system and inject too much fuel. The rich mixture will hit the catalytic converters and result in premature failure. It may also cause your check engine light to come on and result in you failing inspection.

There have been long discussions about this on the Quattroworld UrS forums, there are some guys on that forum that really know turbo's and they are into performance, not sound. Audi's are well engineered vehicles and you can bet that they use a diverter for a very good reason.