OEM Exhaust Mod - Possible in New M3/M4?

[jeremyr4]

First of all, let me send a congrats to everyone who has already received their new cars. I'm REALLY looking forward to trying the new gen. I have owned 3 E46 M3s and I currently have a 2013 M3.

My 2013 has the OEM Exhaust Mod and it literally transformed my car from being disappointing (in terms of it just being too quiet/refined) to being a joy to drive every day. Does anyone know if the OEM Exhaust Mod (non-perforated) can be done on the new gen of M3/M4? While the exhaust and cabin noise seems louder than the previous gen, I'm guessing it still isn't comparable to the previous gen with the OEM Exhaust Mod.

On a similar note, if anyone had the OEM Exhaust Mod (non perf) and already has their new car I would love to hear their impressions of how the sound levels differ - thanks!

Thanks,
Jeremy

[chmura]

Should be similar to the previous M3.

You can probably do the exhaust mod 3 different ways or even more.

1. Looks like there are 2 perforated pipes instead of 4 like in the e92 M3. So open up the can and cover both perforated pipes.

2. Close off the one end of the Y that goes to the canister. On both sides.

3. Code the flaps to always stay open.

[jeremyr4]

Originally Posted by chmura

Should be similar to the previous M3.

You can probably do the exhaust mod 3 different ways or even more.

1. Looks like there are 2 perforated pipes instead of 4 like in the e92 M3. So open up the can and cover both perforated pipes.

2. Close off the one end of the Y that goes to the canister. On both sides.

3. Code the flaps to always stay open.

Thanks for posting this great diagram. I didn't realize it was so straightforward! Given that I probably won't own an M4 for another year or so, I won't be the first to give it a try but I certainly look forward to feedback from others. This was BY FAR the best money that I spent on a car (ever) so hopefully it will yield similar results on the new M3/M4...

[Wild_Will]

If you can afford to properly modify an M car then don't buy an M car.

[CanAutM3]

IMO, there is no gain at doing the OEM exhaust mod on the F8X.

That valve system in the exhaust does exactly what the mod on the E9X does. Look at the diagram, when the valves are open, the exhaust gases flow straight through.

[///M ARMY]

Originally Posted by Wild_Will

If you can afford to properly modify an M car then don't buy an M car.

I have never been a fan of modifying a stock exhaust. Seems cheap. But that's my personal preference.

[Bluehinder]

Originally Posted by CanAutM3

IMO, there is no gain at doing the OEM exhaust mod on the F8X.

That valve system in the exhaust does exactly what the mod on the E9X does. Look at the diagram, when the valves are open, the exhaust gases flow straight through.

+1

[jeremyr4]

Originally Posted by CanAutM3

IMO, there is no gain at doing the OEM exhaust mod on the F8X.

That valve system in the exhaust does exactly what the mod on the E9X does. Look at the diagram, when the valves are open, the exhaust gases flow straight through.

Thanks VERY much for pointing this out. So essentially an OEM Exhaust Mod for the new M3/M4 will just be a matter of keeping the valve open the whole time. Given how different the OEM Exhaust Mod sound was on the E9x, I'm now even more curious to hear the new M3/M4 on Sport+ mode. Sounds like it has potential to be significantly louder than the E9x.

It will be interesting to see if someone comes up with a way to keep the valve open the whole time...

Thanks again for pointing this out,
Jeremy

[aus]

How does the exhaust flow if the valves are closed? Does it flow back through the perforated pipes?

When the valves are open, the perforated pipe looks like a huge Heimholtz chamber, so you might get a little volume if you block off that pipe.

.

[CanAutM3]

Originally Posted by aus

How does the exhaust flow if the valves are closed? Does it flow back through the perforated pipes?

See diagram below: