This thread is a very interesting read. I hope it can be resurrected as I've got a few questions and hope someone could answer them.
I ride an A3 1.5 TFSI COD and my muffler looks like on the picture below. It has two tailpipes on the left side and I need to add two more to the right side as I'm going to convert the rear of the car to the symmetrical S3 look. I've been looking at other options but none of them suited me, mostly being too expensive. I'm not looking for loudness as I like my quiet 1.5 TFSI, however I wouldn't complain if this mod made the sound a little deeper.
What I need is to add two exhaust pipes to the muffler. I spoke to my auto mechanic and he said it wasn't easy. But after reading through this thread I see that it could be done. Could it?
What if to open the muffler from above, gut it, then bore two holes on the right hand side and weld on two new pipes, symmetrical to the existing ones on the left hand side?
I didn't see my muffler open, but I guess it would have the same structure as all the other mufflers in this thread.
May I ask a few questions?
- Why did you put any pipes (perforated or non-perforated) inside the muffler? Can it be as an empty box with a pipe in and a pipe out? What do those pipes change?
- Why to put rockwool inside? For a deeper sound? I can't think of any heat insulation.
- What if to open the muffler, bore new holes for two new pipes and weld those pipes on without removing the original muffler contents? Would it still lead exhaust fumes through all the pipes out?