Ok, Im kinda new to the turbo thing, I dont understand all the lingo, and I dont know a lot of the parts of a kit. Hopefully you'll bare with me here. Ive read a lot on here about turbo kits and swaps. From what Ive read, adding a kit such as the AVO kit to the RS's 2.5 "pretty much max's it out." Yet, for about the same money, you could swap a WRX engine in, have about 220 hp, and lots of room to grow. Why is this? Can you not do the same work on the 25 as you would on the 20 to get "room to grow?" For example, (totally hypothetical, I dont even know if this is needed) if you were going to up the boost on the EJ20 a lot, and needed new headgaskets to take the boost, could you not just do the same thing to the EJ25? I just dont understand why the EJ20 could take lots of power with mods, and the EJ25 couldnt with the same precautionary mods? Thanks.