It is just another heat exchanger. Late 80's early 90's Nissan engine had these types of heat exhangers before the throttle body. They didn't really do a great deal, but would help a little with heat soak. Being aluminium, it will absorb the heat well, but I doubt you would notice any performance improvement.
Nissan Passage RB20ET
Holden Commodore RB30ET
Look similar? Nissan built the RB30 for Holden Australia.