I want to put together:

S4 TII Irons
S4 NA Housings
S4 NA rotors

As a turbo motor. The only thing that the TII housings have that the NA housings don't is coolant passages to the Intake mani that go to the turbo correct? Otherwise, everything is the same?


Thanks

 

NA housings have exhaust diffusers in them.
I'm pretty sure the diffusers in the NA ports are necessary for the proper port velocity to make power.

 

This is going to be a turbo motor, not NA.

 

https://www.rx7club.com/2nd-gen-archive-72/removing-swapping-rotor-housing-exhaust-sleeves-401058/