F80 M3 / F82 M4 exhaust resonator delete and straight pipes

[kitw]

Originally Posted by makasu

I have unplugged it under the car and it completely closes the valves.

Nope. As long as you unplug while they are open, they will stay open. I unplugs mine and they stayed open through 2 drive cycles and about 20 miles of driving.

[Blindside_137]

That 135 sounds so much throatier, and down right meaner.

That's sad

[Dog Face Pony Soldier]

I can understand hiding a cat bypass, but why the need for a stealth look with the resonator? Seems like the long (and heavier) road to China…

[Seth9]

Originally Posted by BuLoOoSki

To each his own, but it sounds too raspy. If anything this car needs a mod that makes the exhaust tone deeper and throatier. This mod IMO just made it sound worse.

[Elaz]

Originally Posted by Phase 9

I'm glad you said it first sounds like a ricer to me.theres nothing like the sound of my e92 with active exhaust.

[Crimson92]

I'll just leave this here.

[Jadar]

Originally Posted by Dackelone

So a friend of mine took delivery of his brand new M4 last week. He did not have it but a few days before the mod'ing has begun!

He had a friend, he goes by the name: New Fiftyninefifty on FB: cut open the factory resonators and welded in, a straight pipe - bypassing the factory resonator - but maintaining a factory "look"! It's a pretty stealth look.

IF anyone lives in Germany and wants to have this relatively cheap mod done... just send me a PM and I will get you in touch with the welder(Nurnberg area) guru.

The car's exhaust flaps are also controlled via a switch in the drivers cockpit. Now you can have the exhaust flaps bypass the muffler when NOT in Sport or Sport+ modes.


Attachment 1051540

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videos after mid pipe delete... keep in mind the exhaust has zero miles on it and will surely change tone(deeper) once the exhaust carbons up some more...

Flaps open vs. flaps closed...
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Let me understand this a bit better...

By the looks of it you slipped in a smaller diameter straight pipe to eliminate the resonator?
Theoretically yes the sound will be louder, but adding a smaller diameter pipe like that will choke off the exhaust and rob hp!

Hope the sound was worth it because I'm willing to bet dynoing before and after there will be a loss in power.
If anything on turbo cars...they must have maximum flow out of the exhaust. Hence why everyone does down pipes..

You need to just cut off the resonator altogether and put in the same diameter pipes. Forget about the stealth looks at this point.

[HP Autosport]

I don't know if I like it with "straight pipes". Most BMW's and gas powered vehicles in general sound horrible with straight pipes if the rest of the exhaust isn't property tuned.

[Jadar]

Originally Posted by Dackelone

Here is another friend's N55 135i that New Fiftyninefifty did a muffler delete(ala M3 style). He cut open the factory muffler and bypassed the perforated internal exhaust pipes. It sounds AWESOME!

Here is the exhaust mod on an e9x N54 335i...
Attachment 1052146
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Yep sounds amazing indeed!!! It's exactly my what I did in my F30.

[InTheNightKitchen]

When you're climbing up a ladder,
and you feel something splatter...

Diarrhea (Cha cha cha)
Diarrhea (Cha cha cha)

[duk]

I don't liek that sound at all

[The long haul]

Originally Posted by Crimson92

I'll just leave this here.

Much better, that's the bees knees!
The 135i sounds mucccchhhh better than the S55! Granted the straight pipes honesty don't sound too bad on the S55 it's just not great.
[u2b]m.youtube.com/watch?v=a-EUllKwP7Y[/u2b]
That's how the S55 note makes me feel

[Dackelone]

Originally Posted by kitw

Do they default open at idle? What's the stock behavior? (I could crawl under the car and look I guess

Originally Posted by W Cole

Im confused - I thought unplugging the valves would mean they stay closed. But you are saying breaking the ground opens the valves??

Ok, I found out more info. When you cut/interrupt the wire to the exhaust valves... they LOCK or FREEZE in the position they are in. So my friend first puts the car in SPORT MODE, then throws his switch to "freeze" the exhaust valves in the louder mode(then goes in cofomfort or eco or what have you.

He is also working on a coding solution... but so far his "switch" does the job quite nicely.


Dackel

[M3guy3]

the 1 series sounds better. Its not as ricey

[Doctor J]

still doesn't sound that great

[mcasseba]

Sounds like a dirt bike

[Falafel Combo]

Sounds better, but still far from special.

[krapnoj]

Originally Posted by Alex07M3

Why does that 135i with exhaust mod sound better then an M4 with Akrapovic!?! :

+1

[Fizik]

And it still doesn't sound better. Agreed 135 sound much better.

[Hokie_BMW]

That is way to beer can/civic-ey sounding for me. 135 sounds way better.

[Lorde]

[jeremyr4]

Originally Posted by Hokie_BMW

That is way to beer can/civic-ey sounding for me. 135 sounds way better.

I agree. For anyone who is interested, the 135i essentially got "OEM Exhaust Mod - Non perforated" if you want to look it up on the E9x M3 threads. I had this done to my '13 M3 Convertible and it sounds AMAZING and only cost me $350! It's the best money I ever spent on a car, especially when you consider how cheap it was!

Also, theoretically, being in Sport or Sport+ mode on the new M3/M4 appears to be equivalent (ie. bypassing the chamber) to the OEM Exhaust Mod - Non Perforated that I mentioned above.

With the positive + negative reviews, I'm certainly looking forward to hearing the new M3/M4 in-person in Sport or Sport+ mode. I am definitely concerned that it will be a huge downgrade in terms of sound vs the E9x M3 but I'm reserving my opinion until I hear it in-person.

Happy July 4th to everyone!
Jeremy