MDR Industries | Billet Intercooler | Honda Civic Type R | FL5 | 2.0T K20C1 | 2023+MDR's intercooler is made in the USA, with machined Billet 6061 T6 aluminium end tanks and a 5. 50 core to replace the factorys plastic end tanks and 2. 5 core. Throughout MDR's testing period, they calculated heat transfers for different types of fins, with different fin heights, and fin densities to determine the best combination internal and external fin to achieve the highest heat transfer effectiveness, with the lowest pressure drop. We then