At TGA, we would love to help you make smart decisions on modifying your vehicle. Useless parts are sold non-stop, so these guides are just suggestions based on our past experiences. This is not supposed to be an exclusive list, but more of a great base for a continuously modified vehicle.
First off, do your research whenever you modify your car from OEM specifications. Make a plan for the future of your vehicle, talk with your installer BEFORE you start purchasing parts, and understand most aftermarket parts do not mate well with other brands. Here are some of our suggested modifications for certain stages; Feel free to make suggestions as this should be an ongoing list. Anything past Stage 2, you want to start looking for a backup source of transportation. A highly modified Subaru requires constant monitoring, just like any race car.
Stage 1Tuner, intake, catback, mild suspension
Stage 2 (270-350hp)
Stage 1 + turbo back exhaust, adjustable suspension, cooling system, oil system
Stage 2+ (350- 450hp)Stage 2 + E85, turbo, fuel pump, injectors, clutch, pistons, EWG
Stage 3 or higher (450hp+)
Stage 2 + larger turbo, drive train, suspension