Help me pick an exhaust

[hunterbs123]

I have a 2008 535xi and need helping finding a good cat-back exhaust. Not looking for anything super loud but louder than stock. Also, keeping it sorta cheap. Thanks in advance.

[pbonsalb]

Is yours already open full time?

[hunterbs123]

No. All stock exhaust. I was looking at the Magnaflow Touring i think is what its called

[interalian]

He meant the butterfly on the second muff. Easy to set it to run 'open' all the time. Sounds a little more growly but not much.

[hunterbs123]

Oh okay. Yeah today I went to autozone and got a vaccum hose connector. Opened up the flap valve. Sounds pretty good... Except I have an exhaust tick at startup.

[pbonsalb]

Could it be loose/worn wastegate flappers rattling until they warm up and expand?

[interalian]

I was considering gutting the baffles from the muffler with the flapper in it. With the flap closed in 'normal mode', it would still be the Helmholtz Resonator it was designed to be, but when the flap opens it would be straight-through. Interesting?

[pbonsalb]

Try it if you feel up for a project. Seems fine in theory. Wound it matter under load that one exhaust had less restriction than another? Probably not if the rest of the exhaust is stock, but one turbo will be working with is a little more back pressure than the other. If these exhausts have a crossover that may not matter. The 535xi wagon is my wife’s car so I have left it all stock apart from a JB4 and have not really studied the exhaust. She would complain if I made it louder.

[interalian]

Try it if you feel up for a project. Seems fine in theory. Wound it matter under load that one exhaust had less restriction than another? Probably not if the rest of the exhaust is stock, but one turbo will be working with is a little more back pressure than the other. If these exhausts have a crossover that may not matter. The 535xi wagon is my wife’s car so I have left it all stock apart from a JB4 and have not really studied the exhaust. She would complain if I made it louder.

There's one fat pipe that splits just in front of the dual mufflers, so less restriction in the muff with the valve would just mean less restriction, and more noise.

[pbonsalb]

Then it seems like it’s worth a try. Aftermarket exhausts would cost a lot more, assuming you can cut open your muffler and weld it closed after gutting it. I have not really followed E60 exhausts so I don’t know what is available, fits well or sounds good.

[interalian]

^that's my problem too. I'm too cheap to spend on a catback system but I have the time.

(Sorry for the thread hijack, OP).