it's easy to go up on power because the oversized parts on an engine not built for it isn't going to make s**t for power initially, and when you start with all the parts that are designed to make huge amounts of power bolted onto an engine that doesn't make squat for power, you have a shitty running car until you finally reach that "due time and end point".its easy to go up in hp often when your list of upgrading is very small lol
So you purposely want to make your car worse for the meantime just so you wont have to upgrade anything later on. You're running boost.....the main things you need to focus on are your block and your turbo to prevent from upgrading. You don't have to touch anything else. 500 isn't some high goal to reach even for that to be your minimal output. You still have nothing to warrant using parts that don't even fit when the correct things you need are readily available. Running large charge pipe is going to increase lag, not running the turbo and exhaust manifold you need for your goal is going to create a crazy high expense, and running a custom one manifold (I would assume a large one since you asked about mine) will help create more power on less boost, but if the block isn't built for that, it's a waste or a ticking time bomb.