Tial 50mm is the best BOV IMO depending on the app and also what I run, but only for bigger turbo/high HP setups. It will dump more air than the K03 can flow!

 

Diverter valves are much better for Audis. How much boost are you running? Just get a fresh stock one for the TT. They hold better than the ones that came in the S4. I run 2 of the TT valves in my S4 at 20psi and they work great.

 

Tial is way better than HKS SSQV

 

Your asking for Police Attention with the HKS.

 

Get a intake... I had a GTI (same motor) and when I got a cold air intake (I had a forge DV too) it definitely gave the car that pssshh sound, and you could really hear the turbos spool.

 

try stasis engineering...

 

you asked this on IWSTI a year or two ago as well, are you joking?

 

A new intake system in combination with the Forge DV will give you the sound that you're looking for without causing issues that you would run in to with a BOV. The splitters (that DV 50% and BO 50%) are becoming more popular, but it isn't a necessity.