Exhaust heat has always been an issue with the Viper. Not many vehicle manufacturers encapsulate the exhaust system in the body. Those who do (like Austin Martin) have an elaborate exhaust ventilation system and numerous shields (many made from Inconel).
On the early Vipers, 1992-1993 your feet would boil in your shoes and you would burn yourself badly on the side sills if you wore shorts. The 1994-1996 models had some improvements to the exhaust insulation and side sill vents that made things better, but heat still was a constant complaint. The catalyst in these models was very large and fully contained in the side panels with no airflow, plus fuel control was not refined, causing high catalyst temperatures. It was part of the nature of the car and the price of admission.
There were many aftermarket fixes for this; we manufactured vents for the front sill panels that would allow air to circulate through the side panels and Inconel exhaust shields that reflected the heat away from the body of the car. High flow cats reduced temperatures as well.
The 03-10 models were much better, the catalyst was split so one half of the catalyst was encapsulated in the side panels, air deflectors were designed to create a low pressure area under the car near the cats, to draw more cool air to them. Still, heat was an issue as you had one catalyst under your feet and one next to it. Aftermarket, vents, heat wrap and high flow catalyst helped those who could not take the heat.
The 2013-14 models are by far the best, with one catalyst under the car, not in the side panel.
One common method of reducing heat is wrapping the catalyst with heat wrap. Beware, this does reduce temperatures but will compromise catalyst life.
Hope this helps.
