[vcx]

Hello guys,

I hijacked another thread about midpipe with my question but I thought it would be better to make a separate thread.

I currently have a 340ix with the MPPSK exhaust.

I plan to add a catted downpipe (probably the Akra), so I can flash my car to a stage 2 tune.

I'm not interested in more sound, only in the performance gains of the DP + stage 2 tune. On the contrary, I'm worried about the extra volume added by the DP.

I know the MPPSK exhaust to be very loud in sport mode, when paired with a DP, and I want to limitate the volume (without altering the tone quality, if possible) as much as possible.

So, my idea is to add a resonator in the midpipe, instead of the straight midpipe that I currently have with the MPPSK.

My questions are:

-does anybody knows if it's possible to change the MPPSK mid pipe with the standard OEM midpipe (but keeping the MPPSK axleback) ? If so, is it "plug and play" between the OEM midpipe and the MPPSK axle back, or the diameter is different, or other problem prevent to do so ?

-would you rather recommand to add a custom-made resonator on the current MPPSK midpipe ? I've seen guys saying that they went to a local exhaust shop, that added a resonator for little money.

-if so, do you know in what way the shape of a resonator influence the tone ? (I rather like muted, low pitched and "cavernous" sound, like Borla Stinger on Corvettes, if you see what I mean, rather than a "metalic" sound, like the e46 M3).

Thank in advance for you answers !

[aardate]

I had the Akro DP and recently added the MPPSK to my 340i. I was a little worried about how loud the car would be and had the same idea. But honestly after hearing it and driving it for a while, I don't think the noise level is at a point where you would need to add in a resonator or a sec.cat. Especially that you can always put it in comfort and its almost stock level of noise (just a tab louder). Cold starts are definitely louder though but I guess you can tame that down with your BM3 option.
Also, the sizing might be a little tricky as the stock downpipe has a oval shape to it while the MPPSK downpipe piece is more round. Anything is doable I guess if you go to the right place.
My advice is to stick with a reputable DP.

[vcx]

thank you very much for your useful insights!

[Jay5k]

I did a dual resonator delete and I added a vibrant resonator in the mid pipe (welded). I have a catless dp and stock muffler. The vibrant resonator removed the hollow and raspy sound and made the exhaust sound deeper.

[AMG KLR]

Originally Posted by vcx

Hello guys,



My questions are:

-does anybody knows if it's possible to change the MPPSK mid pipe with the standard OEM midpipe (but keeping the MPPSK axleback) ? If so, is it "plug and play" between the OEM midpipe and the MPPSK axle back, or the diameter is different, or other problem prevent to do so ?

Thank in advance for you answers !

Yes you can

For OEM midpipe, cut a portion of the rear section of your mppsk of 31.2cm from the end, and then cut the existing mid pipe 45mm behind the resonator weld (bottle shape not oval cylinder)

https://prnt.sc/1gvuusy
https://prnt.sc/1gvv2gh

[vcx]

Originally Posted by AMG KLR

Yes you can

For OEM midpipe, cut a portion of the rear section of your mppsk of 31.2cm from the end, and then cut the existing mid pipe 45mm behind the resonator weld (bottle shape not oval cylinder)

https://prnt.sc/1gvuusy
https://prnt.sc/1gvv2gh

thank you guys!

[Ifellapart]

You should just code it so the valve is always closed. Even with my setup being basically straight piped when the bypass valves are opened, when they're closed in comfort its crazy how quiet and subdued it is.

[anh3]

Originally Posted by AMG KLR

Yes you can

For OEM midpipe, cut a portion of the rear section of your mppsk of 31.2cm from the end, and then cut the existing mid pipe 45mm behind the resonator weld (bottle shape not oval cylinder)

https://prnt.sc/1gvuusy
https://prnt.sc/1gvv2gh

you meant to say 45cm? I'm looking to this, need to confirm the measurements...

[AMG KLR]

Originally Posted by anh3

you meant to say 45cm? I'm looking to this, need to confirm the measurements...

View post on imgur.com

4.5mm

[vcx]

I see that it's possible to buy non-OEM vibrant resonators alone on amazon, which are much cheaper than buying the full OEM midpipe (piece n° 18308638781).

https://www.amazon.com/Vibrant-1792-.../dp/B000E3VHVO

Anybody has experience with those cheap resonators ?

Also does anybody know what inlet/outlet size of resonator is compatible with MPPSK midpipe ?

Thank you!

[Hein Jockins]

This doesn't necessarily answer your question, but I have MPPSK with catted Akra DP and I don't think it's too loud at all as a result of the upgraded DP. Obviously subjective, but to me, the only thing anyone would want to "muffle" would be the crackles and pops of the mppsk tune which can be toned down with a flash tune.

The main difference in sound with the Akra DP is more of a roar in higher revs which I would think most people would want cause higher revs aren't when you're casually driving around a residential neighborhood.

I'm happy to post sound clips if you're interested. I love the combo I have on my car, as it's mainly a functioning of Sport mode (ie. open flaps) + driving in high revs meaning the b58 roar is controllable.

[vcx]

Originally Posted by Hein Jockins

This doesn't necessarily answer your question, but I have MPPSK with catted Akra DP and I don't think it's too loud at all as a result of the upgraded DP. Obviously subjective, but to me, the only thing anyone would want to "muffle" would be the crackles and pops of the mppsk tune which can be toned down with a flash tune.

The main difference in sound with the Akra DP is more of a roar in higher revs which I would think most people would want cause higher revs aren't when you're casually driving around a residential neighborhood.

I'm happy to post sound clips if you're interested. I love the combo I have on my car, as it's mainly a functioning of Sport mode (ie. open flaps) + driving in high revs meaning the b58 roar is controllable.

Thank you for the answer!

I found some videos of the MPPSK + DP combo on youtube but I am always interested in hearing new videos ! So if have some vids, that would be appreciated.

Concerning the sound, I also want to add a vibrant resonator to eliminate the raspy/metallic sound, that seems to be amplified with the metallic cat of the DP (i want a sound a bit closer to the stock exhaust setup, more cavernous).

Anyway, if this project can materialize, I will post videos.

But first, I must find the diameter of the MPPSK midpipe..