Varex or Butterfly Exhaust Muffler
 

Hello 86s / FRS / BRZ / BMWs,

I am looking to get a butterfly valve exhaust and I know which one I want to get, but not 100% sure if installing a butterfly valve exhaust behind the CAT will cause issues. For instance, too much heat as the cat burns away gases created by the engine.

Hopefully someone can give me an idea as I've e-mailed some shops, but quite lazy reply's to be honest.

This the closest I could find to a compact exhaust muffler that can open and close, by Racecraft:

https://racecraftaus.com/products/el...lled-muffler-3

You may be asking why don't just put it at the back, well I have a TOMEI EXPREME TI TITANIUM EXHAUST and trying not to mess with its current cat back setup.

Any help would be great.

My friend and I have a butterfly valve catbacks setup on our cars, but keep in mind that our set up has the valves are located way in the back where a typical briefcase muffler would sit.

https://cdn.shopify.com/s/files/1/05...g?v=1634502727

Most of these butterfly valves can traced back to bulk wholesale items found on Alibaba and from our experience they do NOT like heat. The electronic motor that opens and shuts the butterfly valve may fail eventually. Personally that hasn't happened to me yet but there are rumors. Lastly, the valves will seize and get stuck either full open or full closed. My friend is dealing with that right now. Fortunately, we have warranty so our local muffler shop replaces them frequently (about once a year) no questions asked.