Esiest thing is to tghten all ur piping's rubber. If cannot, dismantle ur intercooler and suppress into water to check for bubbles. if alot comes out then throw away & go buy a trust intercooler (Joking).. Easiest way is to bring it to an experienced mech of radiator sifus..
Ok, here we'll be discussing tyres. I know there is a section on tyres but I need input from Skyline owners as the Wheels and Tyres section mainly discusses smaller diameter tyres and not all are really performance...