1998 328is muffler diameter

[devaul]

I want to get a magnaflow muffler for my 328is but i dont know the diameter in/out size. i read somewhere its 2" but then somewhere else 2.25". If someone could please let me know what the in and out size would be it would be greatly appreciated.

really? noone knows this simple question?

[devaul]

anyone know this?

[flyfishvt]

really? noone knows this simple question?

its January. I'm not real enthusiastic about crawling under the car with a micrometer when it's 10F. Besides. Any place (reputable) that sells them should already have fitment info

Can't you measure your existing pipes? If you don't have a micrometer just wrap a tape measure around it and divide by 3

2" on both pipes is the outside diameter

[keeslinger31]

I've got a 328 muffler laying around somewhere I'll go measure it.
You want the inside diameter i assume?

[flyfishvt]

I only measured the outside diameter where it meets the muffler.

[keeslinger31]

Idk I'm cornfused now. I measure 1 3/4 inside diameter but wrapping the tape around the pipe gets 6 inches and that's 2 but I don't think the metal is that thick. But either way I'm pretty sure the od is 2 inch and the m3 muffler is 2.25 and that is the source of the confusion.

[flyfishvt]

They are double walled pipes....basically a pipe inside another pipe. Reduces corrosion and noise

[keeslinger31]

They are double walled pipes....basically a pipe inside another pipe. Reduces corrosion and noise

Ya but jeeze 1 3/4 is tiny :eek:

[flyfishvt]

But you have 2 of them so its a total of 3.5"

[keeslinger31]

True but Now i have m3 muffler so my midpipe is the only thing left that's 1 3/4

[flyfishvt]

But you're forgetting that you also have the intake to deal with. It does no good to increase the exhaust size without also increasing the intake size.

[dtnorthern]

Two 1.75" pipes is not equivalent in area at least to one 3.5" pipe... lol.

I had a magnaflow dual in dual out muffler installed last weekend. I had heard the pipes were 2.25 and the muffler only came in 2.25 or 2.5, so I got the 2.25". Turned out they were 2" pipes, but it was still easy for my exhaust guy to install and it worked out great. Sounds awesome. They have a shorter and longer version of that dual in out muffler, and I would suggest getting the longer one if you get it because the shorter one is a bit loud.