Ed what the fook has a subaru got to do with anything ? :lol:
Correct me if im wrong but both the 3071 and 3076 use completely different flanged housings with the internal and external gated versions so one will make more power anyways with everything else being equal....i.e t2 and t3, one flows alot more efficiently than the other to start with so is not a good comparisson.
fazz states that 400-450bhp is the limit on an internal gate....this is far from the truth, there are off the shelf options of the gt35 that will do 600bhp on an internal gate and you can go bigger than that on some manufacturers turbos.
a bigger external gate is better at controlling low boost on big turbos as it will allow more exhaust to bypass the turbine, hence why sometimes you can get creep on a smaller internal gated turbo when high up the revs. An internal gate is restricted by its size due to the fact its built into the housing where as an external gate can be as big as you want it to be aslong as its manufactured.
If you were running an internally gated turbo (example 3071) in its higher range, absolutely flat out everwhere all of the time you would probably never have an issue with it being internally gated, if you were poodling about at .9 of a bar all of the time at higher revs you're more than likely to get some sort of issue, either creep or spikes due to the small waste gate not allowing enough gas to exit before the turbine wheel.
the same thing happens if you were to undersize an external gate, if it cant flow enough gas to bypass the turbine boost levels would creep.
