[eddie92x]

Hey guys, my warranty recently ended so it's finally that time. Looking to go stage 2 on my 340i which has MPPSK and want to upgrade the downpipe. I am looking for peoples opinions that have MPPSK and what catted downpipe they went with and why? Two things to note, my budget for the downpipe is around $1k and I am looking to keep the deep beautiful sound the MPPSK produces but just want it to be louder (20%+ increase would be incredible). I've seen several videos where after a cheaper downpipe the MPPSK sounds louder but more tin-canney and raspy which imo is a downgrade and absolutely do not want. I want to keep the deepness and of course want something that performs well and is reliable, but this thread is more geared towards how the car will ultimately sound. Most appear to be 200/300 cell, I'm good with both.

Any videos for reference would also be awesome.

Note: I did search across forums with different key words before posting, and did not find what I was looking for. Feel free to send links to relevant threads.

[vcx]

My car is currently at a garage shop to get a HJS catted DP installed over the MPPSK. I will let you know once it's done!

With any sport DP paired with MPPSK, the sound will be more raspy and metallic. If you want a deep sound, just weld a vibrant resonator (bottle style), like the ones from Vibrant Performance. I bought one but can't install it as the local authorithy will say that my MPPSK is not legal anymore... which is stupid, as the exhaust with added resonator will do less noise than the regurla MPPSK exhaust.

[eddie92x]

Originally Posted by vcx

My car is currently at a garage shop to get a HJS catted DP installed over the MPPSK. I will let you know once it's done!

With any sport DP paired with MPPSK, the sound will be more raspy and metallic. If you want a deep sound, just weld a vibrant resonator (bottle style), like the ones from Vibrant Performance. I bought one but can't install it as the local authorithy will say that my MPPSK is not legal anymore... which is stupid, as the exhaust with added resonator will do less noise than the regurla MPPSK exhaust.

Sick! What made you go with a DP that's almost $2k? Was it the strict emissions in your area? I didn't realize all downpipes would make the mppsk more raspy. I guess now the question becomes, which one downgrades the sound the least?

[vcx]

Originally Posted by eddie92x

Sick! What made you go with a DP that's almost $2k? Was it the strict emissions in your area? I didn't realize all downpipes would make the mppsk more raspy. I guess now the question becomes, which one downgrades the sound the least?

The HJS downpipe is currently the only one legal in Switzerland.

Concerning the sound of a catted DP with MPPSK, others might be able to inform you better than me, but all the vids I saw on internet sounded more or less the same, raspy, which I don't particularly like to be honnest.

Side note: you should also desactivate the cold start sound (you can do this using an app like MG Flasher or others). It will be annoyingly loud with a catted DP + MPPSK when you start up.

[G.Newt]

Sound is subjective. I had CG DS-1 catted DP with AWE catback and it sounded great. Now with upgraded turbo + inlet + VRSF catless + AWE catback, it sounds absolutely mental.

If you want a catted downpipe around $1k, I'd go with CG DS-1. Maybe Mike@x-ph.com can help you out on acquiring one, as lead times are a bit long. It only threw a CEL for me once in my 5+ years of having it and I was on stock tune for majority of that time.

[Skyhigh]

Experience summarised here: https://f30.bimmerpost.com/forums/sh....php?t=1691853

[disintegrator66]

Originally Posted by vcx

My car is currently at a garage shop to get a HJS catted DP installed over the MPPSK. I will let you know once it's done!

With any sport DP paired with MPPSK, the sound will be more raspy and metallic. If you want a deep sound, just weld a vibrant resonator (bottle style), like the ones from Vibrant Performance. I bought one but can't install it as the local authorithy will say that my MPPSK is not legal anymore... which is stupid, as the exhaust with added resonator will do less noise than the regurla MPPSK exhaust.

Hello... any update on the HJS install? Since all retailers want ~$2500 USD for the Akra I might go with the HJS.... love to hear your feedback. Thx

[vcx]

Originally Posted by disintegrator66

Hello... any update on the HJS install? Since all retailers want ~$2500 USD for the Akra I might go with the HJS.... love to hear your feedback. Thx

Hi!

I am very happy with it! really quiet in confort mode, more than I thouight, even with MPPSK (and cold start delete).

Very loud on sport mode when the throttle is 100% open.

The install was made by a shop, so I can't comment about the process but they had no problem apparently.

No check engine light also, and I passed the legal test a month ago without any problem.

So very happy overall.

[dmanb2b]

Originally Posted by disintegrator66

Hello... any update on the HJS install? Since all retailers want ~$2500 USD for the Akra I might go with the HJS.... love to hear your feedback. Thx

If you are in the US AA is the way as it's way cheaper

[Juice247]

I have the AA catted DP with MPPSK. BM3 tune with OEM flaps and MPPSK burbles in Comfort and sport. Cold start is off, GTS roar is on. It's subdued during light throttle as long as you keep it under 3k/3500 rpm when the flaps open.

It sounds great during light throttle and absolutly RIPS WOT in sport w/flaps open. It's such an incredible sound when it's warmed up, the exhaust is opened up, and there is enough pressure to fill the pipe.

It absolutely sucks when it's cold and you use medium throttle. It trumpets with a hollow echo of a ricer that chopped their muffler off. Also cold start is brutally terrible sounding. It just resonates in all the wrong ways.

So I learned to drive around it. Light throttle, shift at 3k or less until warm. Don't let the flaps open in Comfort.

Is it worth it. Yes. Its subdued and kind when you keep the revs down and never fails to bring a smile to my face when I get on it. I'd add a resonator if it would eliminate the trumpet sound, but I don't want to sacrifice the midpipe for a shot in the dark.

Oh, and turn on throttle blips in XHP for the cherry on top!

[disintegrator66]

Originally Posted by dmanb2b

If you are in the US AA is the way as it's way cheaper

True... I've researched AA and it appears to be a quality DP at a very resonable price. The HJS DP intrigues me though; built to survive a nuclear blast, dual chamber 300 cell design, claims of flowing ~93% of a straight pipe, Euro 6 compliant etc.

[Skyhigh]

HJS is sort of the golden standard in Europe.
Akrapovic features the same cat converter (HJS) but has a superior body quality with optimised gas flow - higher diameter inlet and aerodynamically coned outlet. And of course both are Euro 6 compliant, no CEL.

Where did you read that about 93% of a catless thoguh...? Never seen that before, sounds a bit exaggerated...

[vcx]

Originally Posted by Skyhigh

HJS is sort of the golden standard in Europe.
Akrapovic features the same cat converter (HJS) but has a superior body quality with optimised gas flow - higher diameter inlet and aerodynamically coned outlet. And of course both are Euro 6 compliant, no CEL.

Where did you read that about 93% of a catless thoguh...? Never seen that before, sounds a bit exaggerated...

I wanted to go with the Akrapovic DP first, which is cheaper than the HJS, strangely. But it's no more listed as compliant with laws in Switzerland.

Maybe because of the noise.

[Skyhigh]

Cheaper!? Something is wrong there… 😁
Akrapovic has always been min 30% more expensive.

Noise-wise they must be the same. Sound-wise maybe not exactly the same but very close.

[vcx]

Originally Posted by Skyhigh

Cheaper!? Something is wrong there… 😁
Akrapovic has always been min 30% more expensive.

Noise-wise they must be the same. Sound-wise maybe not exactly the same but very close.

https://www.rupteur.ch/fr/produit/ec...pipe-Akrapovic

https://www.rupteur.ch/fr/produit/ec...seur-Sport-HJS

[Skyhigh]

Extremely odd. Don't know the prices nowadays, but the HJS must be extremely overpriced if it is more expensive than the superior Akrapovic…

[vcx]

Originally Posted by Skyhigh

Extremely odd. Don't know the prices nowadays, but the HJS must be extremely overpriced if it is more expensive than the superior Akrapovic…

Strange indeed.

I guess since they are the only legal option, the price went up.

But I still don't know why the Akra isn't law-compliant anymore, if he has the HJS cat inside..

[Skyhigh]

I don't really know what „law-compliant" means in Switzerland. The Akra DP is provided with the same approval as the HJS…
Both are ECE-marked components.

[disintegrator66]

Originally Posted by Skyhigh

HJS is sort of the golden standard in Europe.
Akrapovic features the same cat converter (HJS) but has a superior body quality with optimised gas flow - higher diameter inlet and aerodynamically coned outlet. And of course both are Euro 6 compliant, no CEL.

Where did you read that about 93% of a catless thoguh...? Never seen that before, sounds a bit exaggerated...

A claim made by the US importer Fabspeed:
https://www.fabspeed.com/bmw-m140i-m...rter-downpipe/

[mike@x-ph.com]

Originally Posted by dmanb2b

If you are in the US AA is the way as it's way cheaper

Agree

[vcx]

Originally Posted by Skyhigh

I don't really know what „law-compliant" means in Switzerland. The Akra DP is provided with the same approval as the HJS…
Both are ECE-marked components.

If you check the current akrapovic website, it now says that this DP isn't emission compliant.

https://www.akrapovic.com/en/car/pro...00&yearId=5048

But I don't know the reason behind it !

[Skyhigh]

It has always said that on the website. Also that ECU tune is required to avoid CEL. Reasons unknown, since it is the same HJS cat (type engraved on a plate on the DP), which is Euro 6 compliant.
Maybe just liability concerns.