Product code: FMINDK43
Product Description
- Gains of 13bhp
- Peak torque gains of 8nm
- High quality carbon fibre
- Pleated performance air filter
- No engine management check lights (EML)
- Increased air flow
- Lifetime warranty*
The Toyota Yaris GR has proven itself to be a fantastically capable vehicle since its release, and the development team at Forge Motorsport have been able to work their magic once again to find further improvements. The next instalment, is the release of FMINDK43 the new upper airbox for the Yaris GR.
After continued testing and discussions with owners of Yaris GR’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, we 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 (FMINLD1) performance car part, 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 we would not use a panel filter, but instead a cone filter as shown in the CAD below. 3D scan data was utilised 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.
Due to the sensitivity of the MAF and stock map of the Yaris, a lot of testing was required to ensure that performance was gained without inflicting the driveability of the car – especially as we were changing from a panel filter to a cone filter and an increased diameter. To test this in real world conditions, we created a modular design that was 3D printed and allowed for different variations of MAF position, diameter, and airflow to be tested on road and the dyno. After finding the optimum design, we then reprinted the full prototype and left this on the vehicle. This allowed us to continue our testing to prove out the performance repeatability in real world driving conditions. We also noted at this stage that there is a small gain in induction noise.
Dyno Results
We found that FMINDK43 with the stock turbo inlet produced peak gains on average of 13bhp at the wheels and peak torque gains of 8nm.
The dyno graph below shows a comparison between the stock airbox, the 80mm prototype and 89mm prototype. We ran a total of 8 different prototype variations of MAF height, MAF distance from entry and inlet diameter to ensure that the best solution was used. You can see how sticking to the stock size diameter and MAF position with the cone filter produced a slight improvement to the wheel horsepower, however when increased to 89mm we were able to produce some fantastic gains from such an easy to install bolt on modification.
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