takeuchi wrote:The turbo outlet/manifold inlet are 2inch?
Ehhh, no. The turbo and inlet stub are 1.5" diameter (UPDATE:Maybe not all of them. Mine have a 1.5" reducer and it fits just fine, but later in this thread a 1.75" outlet shows up. Maybe measure yours before buying things.) . Which is fine when it's a 4" hop from the turbo to the inlet manifold, but longer plumbing needs larger pipes to avoid strangling the flow. 2" was the largest I could fit between the chassis and radiator, so that's what I used. It seems adequate- there's very little turbo lag (which you'd get if the pipes were too large), and it's not starving for air at higher revs. Oh and my intercooler has 2" inlets.
I used a 1.5" - 2" elbow at the turbo like this one :https://www.amazon.com/1-5-38mm-Silicone-Degree-Reducer/dp/B015PZKIGA
...and made my own 2" inlet stub, because the old one was aimed the wrong way and I figured I might as well make the new one 2" to match the new plumbing.