Quote:
Originally Posted by Kingtal0n
The larger exhaust doesn't cause anything with a "path of least resistance" since as we already discussed the post turbine and post gate pathways are both expressed in identical pressure units for an OEM style turbine outlet. i.e. resistance is always going to be lower in the gate than going through the turbine because they both share the same destination but the gate is just an open hole where the turbine is a solid, flat surface (the blade surface that exhaust gas strikes is a "wall" to the gas molecules). The capacity for flow rate in units of volume can become much higher going through a turbine because even though path resistance is higher, the cross section area is also much larger. so pressure rises more quickly as the gate jams up with unwanted exhaust volume than when going through a reasonably sized (large enough) turbine.
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One major variable you're overlooking is the design of the turbine housing and internal wastegate valve itself. It's positioned in a way where faster exhaust gases will not flow through it efficiently. Wastegate position is very important in many long tube turbo manifolds where the gate needs to be positioned in a way where its partially facing against the flow of the exhaust. The same is true for turbine housings where the exhaust is flowing at an extremely high velocity in one direction. Its like trying to catch water from a stream with a cup perpendicular to the direction of flow. If you look at the EFR turbos, the internal wastgate is also facing the entry of exhaust gas for optimal wastegate flow.