Sehr interessanter Artikel aus der BMW M2 & M2 Competition Facebook Gruppe;:
„Guys, over the past few days I had many people asking me questions about the exhaust set up for the new M2C. I felt that it was time to shed some more lights on the things. For the sake of making it easy I will go from the back to the front:
Slip-On: This is the easiest upgrade for everyone with a EU-spec M2C. Replace the thick neck muffler and fit a decent one. Hardly any power increase, much better looks and a louder exhaust across the rev range even if you opt for a homologated system. Options enough in the market to consider! Valve control is not legal, but you can add it if you prefer. The slip-on is the ONLY option if you DON'T want a ECU tune on your car.
Linkpipe: Not legal and only for track use, but an option if you feel like going illegal and don't have problems tuning your car. The sound volume goes up considerably when the OPFs are removed. The tune is required to disable the sensors which are fitted at the end of the downpipes. If you don't do this, then your car goes into limp mode.
Sport downpipes: A possible option if your tune requires it, not an option when you leave the OPFs installed on the car. It is a waste to install an improved set of downpipes when the OPFs are still there, because the OPFs are the biggest obstruction in the flow. I have to agree that I also heard that HJS is working on new sport downpipes that don't require OPFs, but with the current software / ECU tune requirement I don't see why you would need them. Anyone would go catless if they really wanted to improve the flow.
Catless downpipes: Totally illegal, and only smart when you have a full cat-back system that replaces both the stock slip-on and the center linkpipe with the OPFs. Installing a catless downpipe without removing the OPFs is not possible! Reason why... Your flow will change triggering the sensors and you will simply burn through the OPFs. Also a catless downpipe means Delete-R and you need to disable the OPF pressure sensors on the downpipes. This means ECU tune! Also I believe the soundtrack will be so freaking loud, you will be pulled off the road every other day by the police for driving a car which is simply waaaaay too loud.
This is the current position when it comes to options. Of course, there are many developments on going. For instance, I have seen displays that go into your dashboard air vent that offer delete-r for your catless downpipes. I have discussed with those companies to develop a delete-OPF option in their displays that allows you to remove OPFs without a ECU tune. Similarly to how these displays have delete-r installed in their software.
There might be more solutions in the future, but for now don't think of installing catless downpipes on cars that have the OPFs and stock slip-on. That is not solving the issue, it will only bring you more issues. If you opt for a better exhaust note, work from the back to the front. Slip-on is the sweet spot for us guys in the EU! Only go further if you are ready to opt for a ECU tune. The rest of the world has way more room to play and can do whatever they want.
Any questions still, let me know!“
(Marc Rutten)
