I already own the turbo. Which is from a single turbo VG30 engine, it was rebuilt and had it's ceramic exhaust wheel changed to a steel item about 1000km ago. So for now it will stay.
The car is intended for weekend/very occasionaly track day use.
Power goal at this stage is at least 150RWKW. The maximum boost this engine will see is about 20PSI.
There are certainly a large number of factors to consider when designing an intake manifold, runner length, volume, turbulance and airspeed are just a few. Unfortunately I dont have the resources or time to trial different manifold designs. The stock plenum and TB size on a 3TGTE is definetly on the small side. I know of someone who designed an intake manifold for a race car as a uni project, hopefully he can give me hand.
I guess the sump should be fine as long as the engine is not subjected to extended high RPM use.
3T-GTE: I am interested in the specs of your engine