[MachF10]

I'm trying to change my F10 535 M Sort from dual to quad exhaust and thinking of purchasing the Dinan Free Flow exhaust. I already purchased the M5 bumper and adapter to fit a quad exhaust but does anyone know if the Dinan M5 or 550i free flow exhaust fit? I don't mind going to a welder and having it modified to fit but wondering if anyone suggests against it? I also have the option of going for the Megan Supremo which make a quad exhaust for my car but would prefer the Dinan model.

[Unspec]

Remus also offers a quad exhaust. I believe the M5 hangers are slightly different from the non-M hanger locations.

spielnicht did some M5 muffler installs recently and can probably chime in better on the M5 to 550i differences.

[spielnicht]

As Unspec mentioned, the rear hangers differ between M5 and non-M5 cars. Muffler shops can work around this by custom welding. But if you're installing something like a full M5 exhaust, you're better served by replacing the rear hangers. If you're just going for the M5 mufflers, you're fine either way. If you're a**l like me and always opt for a true OEM install, the rear hangers will run you $150 between used and new parts. Again, not needed unless you want it to look 100% OEM. 99% of those on the forum don't change the rear hangers when installing M5 mufflers.

Now, one man's definition of M5 bumper/diffuser is different from another. Share a pic of the bumper/diffuser and we can better tell you which muffler will work best. For example - Dinan's 550i mufflers WILL NOT work with true M5 diffuser, straight bolt up or custom welding. Share a pic of the diffuser.

[addy27]

Not to add to any confusion but on stock 550is, the M6 mufflers fit without any issue. The M6 muffler tips are wider apart and so they should fit easily in the stock 550i cutouts. BUT if you are using the M5 diffuser, and other plastic parts that go on the M5 under the diffusor, then you should be able to get them on without mods.

[MachF10]

Originally Posted by spielnicht

As Unspec mentioned, the rear hangers differ between M5 and non-M5 cars. Muffler shops can work around this by custom welding. But if you're installing something like a full M5 exhaust, you're better served by replacing the rear hangers. If you're just going for the M5 mufflers, you're fine either way. If you're a**l like me and always opt for a true OEM install, the rear hangers will run you $150 between used and new parts. Again, not needed unless you want it to look 100% OEM. 99% of those on the forum don't change the rear hangers when installing M5 mufflers.

Now, one man's definition of M5 bumper/diffuser is different from another. Share a pic of the bumper/diffuser and we can better tell you which muffler will work best. For example - Dinan's 550i mufflers WILL NOT work with true M5 diffuser, straight bolt up or custom welding. Share a pic of the diffuser.

Thanks, this is very helpful. The diffuser I bought is the M5 oem version. I haven't installed it yet but will share a picture soon. I'm only buying the catback exhaust, not changing the whole exhaust system. So should I buy the Dinan M5 exhaust instead of the 550i? I showed the my local welder the images of the exhaust and he told me he should be able to install them, but will need to modify the clamps/hangers and the piping but I didn't think the diffuser would be an issue since it's the M5 stock one and should accommodate the two tips?

[MachF10]

Originally Posted by MachF10

Thanks, this is very helpful. The diffuser I bought is the M5 oem version. I haven't installed it yet but will share a picture soon. I'm only buying the catback exhaust, not changing the whole exhaust system. So should I buy the Dinan M5 exhaust instead of the 550i? I showed the my local welder the images of the exhaust and he told me he should be able to install them, but will need to modify the clamps/hangers and the piping but I didn't think the diffuser would be an issue since it's the M5 stock one and should accommodate the two tips?

Here is an image of the M5 OEM diffuser. I have to get it painted and installed

[Unspec]

Originally Posted by MachF10

Thanks, this is very helpful. The diffuser I bought is the M5 oem version. I haven't installed it yet but will share a picture soon. I'm only buying the catback exhaust, not changing the whole exhaust system. So should I buy the Dinan M5 exhaust instead of the 550i? I showed the my local welder the images of the exhaust and he told me he should be able to install them, but will need to modify the clamps/hangers and the piping but I didn't think the diffuser would be an issue since it's the M5 stock one and should accommodate the two tips?

Catback is effectively the entire exhaust, and is what spielnicht is talking about regarding hangers. You need axlebacks if you want to have no/minimal modifications.

[MachF10]

Sorry I meant installing axel-back not cat-back. I spoke to a welder who quoted me between 300-400 for customizing the fitment.

[spielnicht]

So you got a true M5-spec diffuser. That means any muffler made for the 550i will not work with it since the tips sit further out. I mean some can be welded to work, but definitely not the Dinans. Trust me, many of us have already looked into and/or tried.

Any muffler made for the M5 will work just fine, regardless of hangers.

[MachF10]

Originally Posted by spielnicht

So you got a true M5-spec diffuser. That means any muffler made for the 550i will not work with it since the tips sit further out. I mean some can be welded to work, but definitely not the Dinans. Trust me, many of us have already looked into and/or tried.

Any muffler made for the M5 will work just fine, regardless of hangers.

I see, thanks for letting me know. I'll stay away from 550i's mufflers. I was going to place the order tomorrow but will aim for the Dinan M5 model, it's either that or the Megan Supremo's that actually make a quad muffler for the 535's.

[MachF10]

Sorry for the late post…thanks to everyone's input. I decided on going with the Eisenmann exhaust for the 535. I muffler shop did have to modify the hangers since i had a small clearance issue with the m5 OEM diffuser but nothing major.