While I agree that the FA24 is a stronger motor and E30 / 330whp is a safe number, JB4 or any other piggyback is never going to be as good as a custom tune. It's essentially trying to fool the ECU by intercepting signals.Hello folks!
Well I agree not to mess with the warranty but... I went with the JB4 unit (as will all my cars I did) so I have a lot of tuning experience with it. Anyway, did you know just by adding E30 to your *stock 2022 WRX will unleash 30 HP... with no tune or nothing else. Already been proven and I can verify via track times ... yes it does work. Been with the Beta 2022 JB4 since it initiated with a lot of testing. As of now, the latest update seems to have ironed out the wrinkles in the AFRs and EWG arm issue. Do the JB4, get the BMS intake and run Map 4 with a shot of E85 (to make ~E30) = ~ 339 WHP. You'll have to adjust your Fuel Bias and Open loop settings to get the optimal AFRs in which various settings have been already tested, so it's easy to dial in now. You'll see a huge difference. You can knock this stuff off and resort back to the stock setup no problem without the warranty issue.
BT is working on a TMIC which has dual 1/8" NPT bungs. This will utilize their prototype chargepipe injection kit which allows the JB4 to directly control a 5th fuel injector off the low pressure system. They increased the E85 mix to E60, cranked up timing, and got ~381 WHP. They expect this will come more in to play when people start doing larger turbos, straight E85, etc, but they found the side benefit of bypassing some ECU fueling limitations they were previously fighting. Check out their CPI (Charge Pipe Injection) updates to get 400 WHP!
FA24 is a stronger motor (rods, springs, cylinder walls.. direct port injection) so I think 400 WHP mark would be fine. You can still take all this stuff off for warranty issues but it'll be a hassle. Going the CPI (later on) route, might be a hassle taking the setup off & on when taking the car in to address warranty issues or service though
Usually dealers will never know or care if you take off the JB4 before warranty work. But if there's an engine failure, Subaru may ask the dealer to send them the ECU and install a new one. In that case, Subaru can go through the datalogs & easily figure out a piggyback was installed.