I still think that 3in is ALOT of flow for an N/A engine.
Check the Amuse R1000 single exit, its 3in and there is
considarable gains with it.
With those HFC and custom Y pipe, this exhaust will be ALOT les
restrictive than stock.
We'll see
I'll consider changing to 3,5in if I go SC at 500HP for sure
Thx for the comments