[mechamanz]

Hi,

Would this 340i/440i exhaust fit my 320i b48 without any welding or major modifications? It is pretty much the full system being sold at a good price.

Thanks

[mechamanz]

Just to add....the pipe diameter Cat back is both 80mm, but on the image it looks like it bends slightly different?

Has anyone had any experience with this? And, was it just a simple bolt-on job?

[Gen13 F36]

The midpipe area from the catalytic is different between the 2 model. Only the axle back fit.

[mechamanz]

Originally Posted by Gen13 F36

The midpipe area from the catalytic is different between the 2 model. Only the axle back fit.

Are you referring to the pipe between the Cat and front muffler?
In that case what if this bit is cut off and a pipe is fitted from cat to 340i front muffler (as circled on attached image)?

[mechamanz]

Originally Posted by Gen13 F36

The midpipe area from the catalytic is different between the 2 model. Only the axle back fit.

Apologies, please can you advise on what you meant by only the axle back fits?

As per my response above, what if I fabricate a pipe from the cat to 340i front muffler (as circled on attached image)? Would this work?

[sqwinny]

There are no gains to be made if you bought and fitted this exhaust. Look up dual muffler conversion 320/328i. That's literally the difference.

Looks wise, it looks really good to have two outlets instead of one.

[mechamanz]

Originally Posted by sqwinny

There are no gains to be made if you bought and fitted this exhaust. Look up dual muffler conversion 320/328i. That's literally the difference.

Looks wise, it looks really good to have two outlets instead of one.

Yes, I am aware of this - I am mainly going for aesthetics (looking to follow up with some 3.5 inch akrapovic tips), but I understand there is a minor sound benefit (slightly more if i do the ''PE'' mod to it)

[sqwinny]

Give it a shot. The stock 335/340i muffler compared to the 320/328i muffler seems as if it's slightly louder than the stock twin-pipe one side exit muffler. As I literally did this conversion a couple of days ago, I think it seems to be "louder" due to sound coming from two sides of the car instead of one. Friends say the car is slightly "louder" then again I also flashed stage 2 bm3 without a downpipe as I drive like a grandma with hot weather in Florida. Catless Downpipe is on the way to add on the supporting mods.

[Gen13 F36]

Originally Posted by mechamanz

Apologies, please can you advise on what you meant by only the axle back fits?

As per my response above, what if I fabricate a pipe from the cat to 340i front muffler (as circled on attached image)? Would this work?

Yes it will work if you fabricate a something(at the circled area) that will line up to the end of the downpipe.

Also mounting area #7 on the photo is slightly different.

[0liver]

Waking this thread up since I'm hoping to have this done while getting my car serviced on Thursday...

I have the full 340i exhaust system ready. Does anyone know if the circled part above has the same diameter? So that it would in best of worlds come down to cutting the current 320i exhaust and the 340i exhaust, lining it up and welding it together? Or did BMW decide that the 320i should go from 80mm straight down to 65mm at once?

Looking at images - it doesn't appear to be the case - but would LOVE to get some facts

[alexonahurry]

Hi Oliver - you need a couple of other parts to fit the whole system as the exhaust mounting is slightly different. Also the down pipe is on a different position, so not a straight fit. All factory fitted exhaust systems are in one piece but there is a marked cutting point just before the muffler I have done the rear muffler box conversion on my 330i (also from a 440i - see picture below ) and my exhaust shop has just used an adapter from 75mm to 80mm. I would only change the rear box as it is pretty much plug n play apart from the adapter. The cutting point for the 440i is on the same spot than for the 320i (B48) exhaust. I have finished mine off with Akrapovic exhaust tips. The video link is for US cars, they don't need an adapter but it is the same apart from that. The cutting point is explained as well.

[0liver]

Originally Posted by alexonahurry

Hi Oliver - you need a couple of other parts to fit the whole system as the exhaust mounting is slightly different. Also the down pipe is on a different position, so not a straight fit. All factory fitted exhaust systems are in one piece but there is a marked cutting point just before the muffler I have done the rear muffler box conversion on my 330i (also from a 440i - see picture below ) and my exhaust shop has just used an adapter from 75mm to 80mm. I would only change the rear box as it is pretty much plug n play apart from the adapter. The cutting point for the 440i is on the same spot than for the 320i (B48) exhaust. I have finished mine off with Akrapovic exhaust tips. The video link is for US cars, they don't need an adapter but it is the same apart from that. The cutting point is explained as well.

Looks more and more like this will be the most likely option. Cant help thinking that the larger diameter 80mm vs 65mm would help when I go for my custom tune and also add some more sound without be obnoxious.

[0liver]

And there we go. Exhaust is fitted. They fitted the entire 340i system onto my 320i.
Only thing they had to do was cut the piece shown further up in this thread. They then cut the original 320i system in the same area. Welded it together and voila - 100% fit.
Anyone looking to do this - the diameter of this first step of the exhaust is the same on 340i and 320i.

No video as of yet - but exactly the difference I was looking for - subtle.

[alexonahurry]

Originally Posted by 0liver

And there we go. Exhaust is fitted. They fitted the entire 340i system onto my 320i.
Only thing they had to do was cut the piece shown further up in this thread. They then cut the original 320i system in the same area. Welded it together and voila - 100% fit.
Anyone looking to do this - the diameter of this first step of the exhaust is the same on 340i and 320i.

No video as of yet - but exactly the difference I was looking for - subtle.

That's great - you probably the first person with this particular mod. How do you like the sound? the muffler box alone is quite an update but the whole system must be awesome.

[0liver]

Originally Posted by alexonahurry

That's great - you probably the first person with this particular mod. How do you like the sound? the muffler box alone is quite an update but the whole system must be awesome.

Haha maybe. Seems the install was even more straight forward than trying to cut it at the backbox - needing the different steps between the tiny x20 to x40 backbox.

I will try to make a video, family been ill and the plan to meet up with my brother to make a decent video - turned into not happening.

I will see if I can at least make a "startup" video this week 🚀

But all in all - it's most definitely to quiet if it's a lot of sound that one is after, however it is clearly louder than the normal exhaust (but could be partially due to the OPF delete)

Got the cheapest diffuser on stock. Looking to replace it and add m-performance front lip and side extensions during spring this year

[barciacik]

Hi guys, i have catback exhaust from 340i on my 320i. Little bit tricky and good welder will do it easly. I have a question for you, mine exhaust flap is uninstalled (because 320i have not controller and connector for it) for a year. How do you control your flap?
i have it with always opened flap and the sound is crazy good (catless downpipe+BM3) but for some comfort driving i am finding somethink to operate the flap. thank you

[eff32fl]

Originally Posted by barciacik

Hi guys, i have catback exhaust from 340i on my 320i. Little bit tricky and good welder will do it easly. I have a question for you, mine exhaust flap is uninstalled (because 320i have not controller and connector for it) for a year. How do you control your flap?
i have it with always opened flap and the sound is crazy good (catless downpipe+BM3) but for some comfort driving i am finding somethink to operate the flap. thank you

You can buy an aftermarket valve controller. This is intended for *20i cars that don't have an OEM valve. This will give you control over the valve regardless of what driving mode your car is in. It's designed to get power from a 12v socket but you can hard wire it anywhere in your trunk.

https://valvetronic.com/products/ele...d853c7ed&_ss=r