b6tbfmp

I just picked up a gently used C450 with 7630mi and have been looking at modifying the stock exhaust system. I have scoured the forum with what members have done and cant find specifics to my hypothetical idea. I am looking for anyone's thoughts in making it into dual exhaust. Yes, I have considered brand name exhausts. My idea is to remove the resonator and making a dual pipe (perhaps adding an x-pipe where the resonator is) all the way to the Y connector, cut that off and reconnect to the stock dual exhaust?. So in essence, it makes a dual exhaust using the stock setup. Will that setup still have the similar acoustics or just have an awful sound? Some posts describe droning when removing both resonator and mufflers. Thoughts?

Dieseldan9

iTrader: (1)

I am pretty sure that is how the performance exhaust is setup

C43Ayemgee

I was planning on doing the same, I just don't have much time. I was going to cut off the resonator and make it a dual exhaust down towards the mufflers. You will get drone removing mufflers or resonators, but if you can replace them with bullet mufflers so it can resonate some drone.

I was going to cut off the resonator and put in 2 mandrel pipes and have 2 straight pipes going down to the mufflers with an h or x pipe in the middle and replace the mufflers with jones resonators or some sort of bullet muffler

b6tbfmp

I am sure I will get a little more noise/drone with the resonator removal however, keeping the stock mufflers is a must.

C43Ayemgee

Yea, I'd like to keep mine aswell, Just incase you'd like it louder, bullet mufflers are always a great option.
I do believe it'll sound nice with the dual exhaust and no resonator. Hopefully, I can do it soon when i have the time ( I keep procrastinating). When do you plan on doing this?

b6tbfmp

I was planning to do this in the next few months as I go in next week for a full clear bra application. I just got a full exterior detail treatment so they could apply the xpel. After that, then comes the exhaust

konigstiger

Response to your PM inquiry.

b6tbfmp

Just a follow up to this thread that this morning the muffler shop removed the single exhaust and fabricate me a dual exhaust mirroring the PE exhaust except I dont have an H pipe or the valved mufflers. I reused the stock mufflers to avoid possible droning and to my surprise, no drone at all. Initial impressions are the sounds at idle are a tad deeper. The pipes to the xpipe and midpipes are press bend....didnt care if it wasnt mandrel bend because not going to see much of a difference. However, I made sure the bends after the rear diff are mandrel. A U-bend was cut in half to make the 90 bend. Since I drove there, there are no cold starts so that is TBD. The car doesnt resonate much at cruising speeds and appears to be smoother. At mid to moderate loads the burbles are much more apparent in the vehicle. WOT you can definitely tell its louder than stock.
As for the pops and crackles, I lost them after this project so I will do an ECU reset to get them back. Not sure why perhaps the new exhaust flow?? The overall cost OTD was $400...now this was done in CA and shop rates are $125-150/hr.

HTXgearhead

ShakyTom

"I lost them after this project so I will do an ECU reset to get them back"

How do you reset the ECU? My upshift bangs have vanished after a tune so while the tuner looks into it, I could give this a try.

CA400

I've read on many threads that after a ECU tune the pops and crackles are lost but come back after driving the car for a few days/weeks. Search "lost pops and crackles after tune" I'm sure you will find lots of info. Pics look good and the price sounds very reasonable!

Alex

ShakyTom

My car pops and crackes like crazy on overrun as part of the tune, but the stock 'bangs' when upshifting are gone.

So there is a chance they will come back over time?

b6tbfmp

I apologize for that. One was for the diameter of the piping and the other is to follow up. I should have check and didnt realize that you could review past posts.

My tuner says:

OPEN YOUR HOOD, CLOSE YOUR VEHICLE DOORS AND ENSURE THAT THE VEHICLE HAS BEEN OFF FOR AT LEAST 10 MINUTES.
- Disconnect the two battery terminals. Negative (black) and Positive (red)
- You can use the red cover that once covered the "positive" terminal, put back into place to keep the positive terminal from touching the battery
- Once disconnected, let the vehicle sit for about 5-10 minutes.
- Now, carefully without touching the battery, take the positive and negative "wires" and touch them together.
- Again, make sure you are NOT connected to the battery or touching the battery in any way.
- Once this is done, you can put the terminals back onto the vehicle.
- Now your vehicle's ECU and modules in the car have been fully reset.
I think this discharges the capacitance with all sensors. I did this before I reinstalled my ecu back from my tuner......my pops and crackles disappeared and reappeared the next day.

[QUOTE=CA400;7590525]I've read on many threads that after a ECU tune the pops and crackles are lost but come back after driving the car for a few days/weeks. Search "lost pops and crackles after tune" I'm sure you will find lots of info. Pics look good and the price sounds very reasonable!

Thanks! This is true, you can wait a day or two but I want to ensure whatever sensor that detects exhaust flow takes note of the reduced back pressure

b6tbfmp

Tom, they will come back. The dual exhaust I just did makes them more noticeable. I am very happy.

CA400

b6tbfmp

Definitely felt more torque and power...no loss at all. The boost spooled faster. Dp's are coming so will let you know when I get them installed. I just installed semi forged 20s onto my car today so I know it will affect the acceleration! I got all my pops and crackles and its ridiculously louder like what a PE would sound!!! I couldnt believe it.....kept on asking if this is my car I am driving.

CA400

waisoserious

Without Resonators it will definitely have some low/mild drone. And since you did not change your muffler to something valved, there will be no way to turn off the drone when you are in comfort/eco mode on the freeway.

But when youre on it, it will sound good.

Personally I think you should just get a custom valved muffler/midpipe setup.

I have a custom exhaust on my GLC43 and thats my experience. It would be a bit irritating if I could not close the muffler valve when I want to be quiet. You need to realize that after you delete the resonators the car will be louder than before and any drone you had previously as stock will be magnified. Just because you want the car louder now does not mean you will want the car loud all the time after you delete your resonators (when the car will be much louder).

b6tbfmp

Deeyounee

This is something to consider - I find my C400 to be so quiet and tame, no pops, bangs or burbles.

Hoping doing something like this with intake and tune with really liven this sucker up

CA400

I was thinking the same thing. I was just thinking that maybe the C400 has different mufflers then a C450/C43. Making the sound different, I do have a ECU tune and was told that burbles/pops were added. I can hear them slightly on S+ mode when the car downshifts. I was wondering if maybe this would make them louder? Definitely a tons cheaper then aftermarket exhaust, but aftermarket exhaust has been tested. I just would hate to cut up the OEM system then need to put it back.....oooh the choices!!

Alex

Deeyounee

Hey Alex,

I think you and I are looking to do very similar things to our cars so let me know what you find out or decide on.

I came from a C63 so having little to no exhaust sound has been somewhat disheartening. I do however love the comfort, ride quality and look of the car - just want to give er a lil nudge in the right direction

b6tbfmp

Alex, the exhaust is different in the C450/C43 compared to the C400. Your exhaust has 2 post resonators, one where I removed mine and one before the rear diff. I am just guessing the mufflers are different too.

CA400

Thanks for that info. I wonder how different the sound would be, because if I did the this all the piping would be the same except for the mufflers?

I'm going to look for a shop around me that does mandrel bends and talk to them about this, without cutting up my stock exhaust.

b6tbfmp

Here is a suggestion Alex, for the big bends use U bends for the 90s...most muffler shops charge about $45-60 per bend. For slight offsets, slight bends, you are not going to see performance loss with press bends vs. mandrel IMO. The muffler shop who did my exhaust quoted me $1k -1500 for a mandrel bend using pre cut bends. So I was shocked to hear that you can buy an AWE for that price. Certainly you call.