Shouldn't be hard to map for, you will be using the same maf sensors so its just a case of rescaling the Maf table to allow for the increased diameter.... Should be no different to adding a 80mm and any old induction kit.
You shouldn't suck in hot air given where the intakes sit and they appear pretty shielded. Get the SVM cold air ducts put in the bumper If you are concerned
ask your tuner what they think, otherwise i would recommend something else ... i remember the discussion about it...
any one have the Injen intake system on their gtr review comment? - Engine - GT-R Life
gotboost has the best design intakes and the best filters (green filter) and its affordable. just one option of many to choose from.