FMINDK43
After continued testing and discussions with owners of GR Corolla's, the stock airbox has proven itself to function well, especially with the stock map. However, the weakness in the airbox is most definitely the quantity and directional flow of the air.
As such, Forge explored several different avenues, before settling on a replacement upper airbox that mounts to the stock lower. When used in collaboration with the Forge Motorsport Inlet Duct, it ensures a consistent cold feed of air into the lower airbox that can then be delivered into a refined upper airbox. The increased diameter from 80mm of the stock inlet pipe to 89mm produces a volumetric increase of around 20% in just the connecting pipe from turbo inlet adapter to the airbox alone. After running data and tests it was decided that Forge would not use a panel filter, but instead a cone filter as shown in the CAD below. 3D scan data was utilized to ensure that the cone filter would fit in the optimum position inside the lower airbox, not just for ease of fitment but also to allow for optimum flow into the inlet tract.
*May cause CEL (p2C90) on 2025 model years. CAN BE ELIMINATED VIA TUNING NOW!
