adam525i said:Is 4-500 hp your goal here or is it just nice to have that headroom built into the block so at 300 hp you can just enjoy the car? Is there a reason the EZ30 is an option but not the newer EZ36?
No, based on performance with ~200WHP I think anything beyond 300WHP would be stupid. I want the headroom of "reliable at 400HP being asked to do much less".
The EZ36 has some changes that make it more challenging to use. It's DBW only, which is managable, but also has offset connecting rods which make aftermarket availability lower and many in the Subaru Trackday community doubt their reliability for high RPM track work. The EZ30 with it's shorter stroke runs traditional rods that don't have these compromises and is available with a Cable Throttle body. It is also the EZ recommended by the track community.
For sure whatever engine goes back in is getting much more dyno time and a much more gradual introduction that will find issues before they become catastrophic. I think putting the WRX motor I have in and running the car a a few autoxes and some lower pressure track events is probably a good approach then do an IAG type motor over the winter unless I decide to do a swap of some kind.