I have a few questions:

1. How huch hp 2" (50mm) IC piping is good for(facts if possible)? Ive heard that 60mm piping is good for 550-600hp...?

2. Is it useless to swap fd throttle body to fc if I have "only" 2" FMIC piping?

I everything goes well I have 350+rwhp next summer in my FC.

 

2" bit small but should work
FD mani and TB on FC is not really for power, just for looks and for having much more space around fuel rails

 

well the fd manifolds/tb will gain you like 10hp but it is a lot of bullshit to make it work. i just use s5 manifolds and a TB-FMIC adapter.

 

I would say 3" Although I am not a TII guy at all yet. Even our CAI is (way) over 2" ID it is for N/a's though. But I would imagine that TII's require more from intake just like they require the largest exhaust for the most power.

Santiago

 

I believe the GReddy kit uses a combo of 2" & 2.5" or something similar. I would expect it to be good for 400+hp.