if am not mistaken both are the same, function as below
An oil catch can/tanks purpose is to separate and hold (catch) any oil and/or oil vapors from entering the intake or atmosphere through the crank case ventilation system.
The OCT is to catch oil vapour from the PCV valve that's usually routed to the intake manifold / TB.
Breather tank is to ensure coolant it not wasted in a radiator / cooling system. Not exactly sure why you'd need one since we have a overflow reservoir.
my external wastegate down pipe around 1 feet long.. the sound not really nice la.. a bit like like rotary sound peekssss like when air dumping.
how long u ppl run? what kind of tone u get with the pipe distance...