Posted this on i-club with no response yet: I understand that the stock downpipe as well as several aftermarket downpipes have a flange that covers the turbo wastegate. Because this flange doesn't allow the gasses to flow easily, it could cause boost spikes, especially with a higher-flowing uppipe or downpipe. Some other downpipes (Bosal) have a separate pipe for the wastegate that empties into the downpipe further down the line while others have single-hole bellmouth design that flows both into the downpipe at the same opening. So, my question is, what would happen if I drilled a hole in the flange of whatever downpipe I decide to buy (HKS, Stromung, etc.)? Would that cause any problems (hot gasses being released into the engine compartment)? Would it have similar benefits to the other downpipe designs? Does anyone know?