I am getting a T3/t4 hybrid now im going to run 2.5 custom piping to the intercooler. My question is....how do you figure out what size intercooler is right for what your using it for? I will be boosting my b18b later on 17-20 psi after i do block work. Any suggestions??

 

Well what I would do first is measure how much room you have bumper wise, then you can break down and observe your options from there.

 

go to http://www.spearco.com

then look at the sizes of the intercoolers and find the one that fits in your bumper with least mods. I got the biggest that fits without modifications...its not a huge one but still a nice size....I also have a GSR with a t3/t4 hybrid and plan to boost 17-20psi like you. I bought a 3.5x24(i think)x6 and had the end tanks done and polished by a local shop...looks very nice!! Just remember end tanks will add approx 6 inches or more to the total length so watch the length...also dont get it too low or youll hit it on parking stops or too thick or youll be doing some mods to the bumper....I did it right the first time...its not real hard....hope this helps.