In 2015 the Dodge Charger adopted a much more tapered rear fascia, compared to previous model years. This taper offers an aerodynamic benefit and, in turn, improved fuel economy. However, this taper caused the fascia to move much closer to the rear exhaust resonator than it has been in prior model years. Computational Fluid Dynamics (CFD) simulations showed that the surface would be about 275° F, hotter than the melting point of the plastic.
I coordinated with Design & Release Engineers and led the development of a heat shield made of recycled polyethylene terephthalate (PET) backed sheet of aluminum was designed to protect the fascia. PET is a carpet-like material that acts as a buffer between the aluminum and plastic fascia. It dampens any sound vibrations created from the heat shield hitting the fascia. The aluminum reflects the radiation from the exhaust and protects the fascia from melting. CFD with the heat shield in the simulation model.
Before any pre-production vehicles were made, I requested carbon fiber prototype rear fascias to be made with representative fascia material samples for initial validation in FCA's climatic wind tunnels. The plastic patches survived with the heat shield, but melted when the heat shield was removed, supporting the virtual analysis. Final validation of this heat shield occurred on pre-production vehicles. I led a trip to the Mojave Desert with instrumented vehicles during the summer of 2013 for testing in extreme heat. One of the main tests conducted in this region is a Davis Dam Trailer Tow test. Davis Dam is a 6% grade that ascends 3000 feet on the border of Nevada and Arizona. This test is a Society of Automotive Engineering (SAE) standardized test - SAE J2807. All vehicles across the industry must complete this test to be considered compliant. The data collected during this trip validated that the heat shield is sufficient in keeping the rear fascia below goal temperatures, even in severely hot environments. The heat shield has been added to all 2015 Dodge Charger models. These include: Charger R/T 5.7L Charger Pursuit 3.6L Charger SRT Hellcat 6.2L.