Hi all,
Wondering if you all can ELI5 (Explain like I'm 5)
Recently purchased a Carrera have decided my first mod will be a SW chip and modifying the exhaust. I know there are a million threads on that but first if someone can help me explain (or confirm if my knowledge is correct) the exhaust system in a 911.
Looking at this image belowand reading some articles this is what I've concluded
- Heat Exchangers are just headers with metal boxes around them to help heat the cabin
- Headers connect to the cylinders and push the exhaust fumes through the exhaust system
- Cat converter makes bad gasses into good gasses (ELI5 version)
- Muffler/baffles make exhaust noise quieter
Here is an image I made from what I understand is the stock 3.2 exhaust system. I just don't see the catalytic converter in it, I did google searches of what it looks like and can never find it in the pictures of stock exhausts.
Now in my research for SW + exhaust there is a lot of talk about pre muffler and cat-bypass.
Can someone ELI5 what a pre-muffler does and how it is different from a cat-bypass? One can assume that a cat bypass is just a pipe that replaces the cat converter, thus making exhaust fumes bad for environment at the cost of a better engine note.
However, upon my reading it seems that if you were to install a pre-muffler or cat-bypass, it is one or the other.
If one were to modify an exhaust system, am I correct when I say you MUST have:
- headers/heat exhangers (these cannot be replaced by other components the way a pre muffler replaces a cat)
- piping from headers to muffler (your choice of cat, pre-muffler or cat-bypass)
- muffler to tail pipe (e.g., M&K sport muffler)
Lastly, if you get a SW chip, would you have to tune it differently depending on what muffler you have? I'd like the Bisimoto Pulse chamber but as far as I know that only replaces the muffler/tail pipe, to make the most out of a SW chip, I've read that it's best to get a pre muffler or a cat bypass as well.
I intend on keeping the stock heat exchangers on there unless that is a bad idea.