[nikolausv]

Hello

does anyone know if you gain any extra power by replacing the stock exhaust with a performance exhaust? From what I have heard you need to exchange the stock catalytic converter to a sport version and combine it with ECU tuning but there is no point in replacing the stock exhaust. Do you agree? Thanks for your advice.

Kind regards
Nikolaus

[GoSpursGo]

Yes you will get extra power by replacing the stock exhaust but you wouldn’t notice it.

It will sound a lot better though...and it allows for future modifications with the tune, upgraded turbos etc etc.

[Billfitz]

You might get some gains, but nothing huge. Compared to most cars the stock BMW exhaust is a performance exhaust. That's one of the things you paid the big bucks for.

[rjd_F30]

pretty much what these guys said. not unless you have supporting mods like a tune, big turbo setup etc. also, from what I understand the only part of the exhaust that can make a difference even with supporting mods is downpipe and resonator section (mid pipe?). hope this helps

[nikolausv]

Thanks for all helpful advice. I am planning to do an ECU tuning combined with a new race catalytic converter. The questions is - is the resonator section a bottleneck and needs to be replaced also? What ECU tunings do you recommend? Thanks

[rjd_F30]

Originally Posted by nikolausv

Thanks for all helpful advice. I am planning to do an ECU tuning combined with a new race catalytic converter. The questions is - is the resonator section a bottleneck and needs to be replaced also? What ECU tunings do you recommend? Thanks

quick question: is your car a diesel? I noticed that in your description it said that and if in fact you do drive a 320D I have no idea about anything regarding tuning them, and you're in the wrong part of the forum. If you do have an N20 like the location and title of this thread would suggest, I apologize and disregard what I just said. Hi flow cats + ECU tune is a good combo and should yield some significant power gains. I would recommend BM3 ECU tune, or if you're looking for something more simple, Dinantronics sport. The dinan is a piggyback, and can only manipulate a few variables, mostly boost. It will be much easier to install, cheaper, but will give you a bit less power than BM3. BootMod3 is a full ECU tune that can manipulate all the necessary variables within your engines tuning to get good, reliable results. it will be more of a process to install, more expensive, but more customizable and will get you a bit more power than Dinantronics. Also, if you have the money, I would recommend getting an M Performance exhaust. It wouldn't give you any more power as it is just a muffler, but it does sound great. I just clicked over 1500 miles on mine and it really is great. So: Hi-Flow Catted Downpipe + ECU Tune (BM3 or Dinan) + M Performance exhaust. That is the setup I would recommend. Hope that helps. Damn that was long, sorry.

[nikolausv]

Thanks for your long and informative answer! I actually have two cars for the moment but I will sell my 325D soon :-) I am not interested in piggyback solutions.

How does BM3 work? Can I install the new map myself by connecting a laptop/smartphone to the ODB port? Can BM3 crack the BMW tuning protection? How is this done - do I have to send the DME box to someone to crack the tuning protection? Is the new map included when I by a BM3 and is this map well tested for the N20? I am a computer engineer so I am sure I can do it :-)

[rjd_F30]

Originally Posted by nikolausv

Thanks for your long and informative answer! I actually have two cars for the moment but I will sell my 325D soon :-) I am not interested in piggyback solutions.

How does BM3 work? Can I install the new map myself by connecting a laptop/smartphone to the ODB port? Can BM3 crack the BMW tuning protection? How is this done - do I have to send the DME box to someone to crack the tuning protection? Is the new map included when I by a BM3 and is this map well tested for the N20? I am a computer engineer so I am sure I can do it :-)

Gotcha. I actually run Dinantronics sport on my car not BM3, so I can't speak to how it is installed from personal experience. I can however vouch for it's quality as I've researched and read on it extensively. it's probably the best non-piggyback tune available for the N20. so good choice! according to pro-tuning freaks' website (FAQs linked here https://www.protuningfreaks.com/pages/bootmod3-faq) the DME has to be taken to a licensed dealer or sent to them to get it unlocked and available for tuning. after that, it's a bit complicated, and they can explain it better at the link I attached above than I will be able to here. If you're a computer engineer, I trust that you will be able to figure it out lol. In my limited flash tuning experience on my cousin's C5 RS6, the tune for that car was simply sent to me via email to download onto a flash tuner, which I plugged into the OBDII and flashed away. I would imagine it should go something like that for you and BM3 if that's what you decide to do. Once installed, it works like any other tune. It changes ignition timing, fueling/AFR, boost pressure etc. to give you about an extra 50+ hp and 50+ lb-ft. BM3 is relatively popular and well liked. I haven't heard any horror stories either, so I guess you could say it is well tested by our n20 owner community. it will definitely be reliable for you, as long as you don't go crazy with other mods.

[nikolausv]

Thanks again. I have emailed pro tuning freaks about how I can remove the OBD lock since I live in Sweden and also if their stage 2 is installed and well tested. No answer so far.

[nikolausv]

Has anyone tested mod3 stage 2

[435MSPORT]

M sport exhaust sounds very awesome.( Catless is a must) I was debating between Akrapovic exhaust and M sport. The Akropovic does not sound any better than M sport + cost more) and sounded more throaty. A friend of my just bought a $129K of Porsche, the Porsche does not sound as close as my M sport. You will enjoy it even more when driving in downtown in 3rd or 4th gear due to close surrounding. The tonality will excel.