Side Sill Insulation (Recap)

[All Blue ACR]

I replaced my stock cats with RT cats and later added a 3" Belanger catback and headers. The RT cats made a huge difference in side-sill heat reduction. The RT cats are running 200 degrees cooler than the stock cats. Also, the aluminzed steel in the Belanger system seems to cool off quicker tham the stock pipes or the stainless steel catback I had prior to the Belanger setup. I then added my own version of vents to the front of the sills to allow air to circulate through the sills and push heat out through the back of the sills. No insulation was added. Amazing how much room is gained in the sills by removing the stock cats. Air now has a way to circulate through. My sills are much, much cooler to the touch. Hi-flow cats and side sill vents are worth the investment and seem to do the job. The principle is simple...get air moving through the sills so that the heat has somewhere to go other than inside the cabin or roasting side sills.

Can you share your vent setup please. This task will be first on my list when my car arrives

 

[ViperTony]

PartsRack carries side-sill vents here. DC Performance has a different version of vents you can see in this thread. I had the front wheels and side sills off one day, saw the drill laying around and decided to drill holes to create a pattern like the DC Performance vents. Had I used a template the end result would be much more appealing but who cares as its behind the wheels. Someday I may actually install the DC vents but for now I'm happy with my drilling adventure.

To keep crap out of the sills, I cut up one of my aluminum window screens and epoxied it to the back of the vents using JB weld. Nothing gets in there but air. I don't normally drive in the rain but I did get caught in rain on my way back from the track in august. When I got home I took off the sills to see if any water was in there. Very little was in there, less water than I would have after washing my car. It appeared that most of the water that got in had evaporated. There's plenty of distance between the vents and the cats so there's no chance of water splashing up onto the cats and damaging them. I don't normally drive in the rain so water in the sills is not a concern for me. I made this mod 4K miles ago and I've had the sills off several times since then and so far no issues.

If I were to do this mod again, I'd buy the vents from DC performance since they would look better than what I did and seem to have a greater area to allow more airflow compared to the PartsRack vents and rain is not a concern for me. However, I would still install mesh behind the vents to keep stuff out.