So I want to upgrade my stock muffler ( '09 Toyota Camry ) but I don't want to use a performance one.
I want to take my current one off, and add a perforated piece of pipe in between the input and output ( sort of like Magnaflow ). Any tips or tricks to do this would be appreciated, and also how should I tune the car afterwards to run the same or better with that free-er flowing muffler?
I'm not understanding what you're trying to "upgrade"...do you mean removing the muffler and putting a pipe in it's place? You can do this, and it doesn't require any engine tuning whatsoever. Power gains are very minimal to none with a muffler delete (at least on NA engines); it will only make your car louder.
Don't.
Just don't.
It is going to sound like a weed whacker, you'll actually lose power.....just...no.
WHY do you not want to upgrade to a performance muffler when you want more airflow from the exhaust? That is, literally, exactly what they are built to do.
If you want to change tone, buy a muffler like a Magnaflow. Don't rig something and straight pipe it. It is terrible for the engine, it sounds horrible, your back pressure will be all thrown off. There is a reason companies spend millions of dollars R&D'ing mufflers. If you don't want drone in your car, and don't want to be slower than you were before, don't slap perforated pipe on there.
You wouldn't have to tune anything. There would be no gains to be found and essentially it would be the same as driving around with your muffler busted off.
