IAG FA20 Block Reccomendations
 

Hello all,
Currently running a ‘13 BRZ with E85, UEL Headers, Invidia N1 Catbcak, Berk Front Pipe, Catless overpipe, and an OFT stage 2+ tune. I’m planning on adding a JR Supercharger C30 and DD at around 9psi, which block would y’all recommend and any other supporting upgrades like clutch?

You do not want to build a block for a centrifugal supercharger at 9 psi, your stock engine will serve you just fine. To add on with more information, I would recommend upgrading as needed - a clutch would be fine but may be unnecessary (I would recommend the Exedy stage 1 clutch, uses stock flywheel and drives almost like stock). I imagine you've got some upgraded injectors and fuel pump if you're running E85 - but let us know what you've got for fueling.



The reason I recommend not getting a block or clutch is because of the power delivery. A Centrifugal supercharger is very linear, which means it's generally forgiving compared to most other application styles of forced induction. The clutch won't be seeing much torque until high in the RPMs, and at high RPM, the load is sustained for a minimal amount of time, meaning the clutch and engine both don't get a whole lot of stress compared to having torque very early in the powerband.


Getting a built engine may seem like the cool reliable thing to do, but the highest reliability you can have is the stock engine that came with your car, unopened. Removing the direct injectors means putting them back in - your seals can be torn through this process and you could have headaches for a long time if any of them have damaged seals. You can lose bolts and have to re-buy some, which can be a lengthy process through the dealer. You have to strip the sealant off of everything and risk damaging mating surfaces in doing so. You risk not sealing the new engine properly in a variety of places, which is never a good thing. You have to perform break-in on the new engine and are relying on it having been built near perfectly. You risk oil passage obstructions if you re-sealed excessively and the sealant ends up coming off of whatever it was supposed to be sealing inside the engine.



Another thing that can happen is the "may as well" thought process, which can becomes excessively expensive. "May as well replacing the timing chain and guides since we're here." "May as well get all new valve springs for high RPM" "May as well do all new coils and plugs" "May as well get the TODA high volume oil pump" etc. Do you get what I'm saying? I am not trying to be a ****, far from it. You may very well be familiar with every word I have said and are excited to start your journey - that's great, if so. But today's social media world paints a fantastic, exciting adventure with modifying cars and the truth needs to be known that it can become ugly extremely easily. I would have stuck to my original stock engine that ran perfectly fine, if I had not been a J02 recall victim.