The Unofficial Aftermarket Exhaust ~2000 RPM Vibration Thread

**xxdunnxx** · 02-07-2017 01:18 PM

Hey,

There are posts all over the forums about people with this problem AWE, APR, Borla, and Magnaflow all alike. Lets solve this and bring it all into one place.

The problem:
Car shakes and vibrates from 1500 to 2000 RPM on acceleration an deceleration
In park/neutral the downpipes can be seen shaking in that rev range
There is no evidence of the exhaust touching anywhere

What I've seen:
People have this issue on other cars as well
It can be caused by harmonic imbalance
As the flex pipe warms, it actually tightens up, rather than loosens
At cold start, the vibration is lower in the RPM range (1500 RPM)
Once warmed up, the vibration is higher in the RPM range (1900 RPM)

What I've tried:
Tighten all clamps
Re-adjust
Added resonators
New resonator-less down pipes
Exhaust Vibration Damper (2x Dodge part 52103612AA)

The fix (for now)
Exhaust vibration dampers were used (2x Dodge part 52103612AA) where the downpipes angle in towards the middle of the driveline, behind the transmission. Utilizing two U-bolts, I was able to sufficiently clamp them on. If they are clamped on any further back, they seem to have no effect. The vibration has nearly completely subsided since adding.

I'm pondering the idea of bracing the downpipes in that location by welding a bar between them, as that may also solve the vibration. If anyone wants to give that a go, please update the thread!

Who has this issue?
What have you done to fix it?
DSG or 6MT?

**theweebabyseamus** · 02-07-2017 01:26 PM

I do get a slight vibration around there. AWE touring with resonated downpipes. DSG

**LittleDozer** · 02-07-2017 01:34 PM

DSG here. I have the issue. Didn't have it with OEM exhaust, barely had with with Stasis non res DPs + Stasis Challenge, now have a significant shudder with Stasis non res DP + Borla Sport.

**PSUGOLD** · 02-07-2017 01:53 PM

I have the issue around 1800 RPM with the Borla exhaust. I had it before around 2200, the front pipes were vibrating. I had a leak in the pipes, Borla sent me a new set, problem was solved. It came back about 2 months later, but this time around 1800 RPM. On cold start the front pipes vibrate from 1200-1800 or so, but once the car warms up it sticks to 1800 RPM for the vibrations. I have looked under the car, it is definitely the front pipes shaking. I have another set here, but have not installed them yet. Waiting until Spring.

DSG here too.

**SportVier** · 02-07-2017 02:00 PM

I get a slight vibration only while engine braking through ~1800rpm. AWE Touring with rez DPs. I have been meaning to take a look for a while. Was assuming I just have a clamp that is hitting the heat shielding somewhere.

**volyer** · 02-07-2017 02:01 PM

I have noticeable shudder/vibration around 1200-1800 rpm while decelerating. OEM exhaust with Magnaflow non-res x pipe. I am eventually going to look at it to see if the clamps or mounts are loose. DSG.

**Michaelds4** · 02-07-2017 02:22 PM

I have the same. 6mt around 2k

**Trent212** · 02-07-2017 02:26 PM

I have headers and non res AWE down pipes and an x pipe and this last week the headers vibrated loose my down pipes. Around ~1500rpm if you give it gas it has a tin sound that appears to be a rattle like 2 things are touching that shouldn't be.

**jimrobbington** · 02-07-2017 02:29 PM

I actually don't feel like I have this problem with my custom exhaust. But I've had the problem on two previous vehicles and the cause was always the downpipe/flexpipe rubbing against the transmission or a cross member of some sort. Usually it only happened under load, or with the AC on, or while turning. It would be much worse during wet weather when the exhaust is constantly being cooled, making it stiffer.

Sent from my SM-G930VC using Tapatalk

**tar** · 02-07-2017 02:33 PM

No rattles here 6mt stasis setup

**extratime** · 02-07-2017 02:40 PM

Awe touring with resonated dp's. I also have this issue around 1200-1500 rpm. Seems to mostly come from driver side resonator on my car. I did hear it the other night on passenger side while pulling into my grage though.

**xxdunnxx** · 02-07-2017 02:53 PM

Thanks for all the replies so far. Lots of people with the same problem but nobody has mentioned a fix for it!!! I will not stop until I find a fix for this. I wish one of the companies that makes the exhaust would do some R&D on this issue. It baffles my mind!

I think I might be onto something with the damper. BMW uses them on stock and performance exhausts for their cars. It may be a viable solution here.

Anyone here an engineer that could explain why this might be happening?

**extratime** · 02-07-2017 03:43 PM

Originally Posted by xxdunnxx

Thanks for all the replies so far. Lots of people with the same problem but nobody has mentioned a fix for it!!! I will not stop until I find a fix for this. I wish one of the companies that makes the exhaust would do some R&D on this issue. It baffles my mind!

I think I might be onto something with the damper. BMW uses them on stock and performance exhausts for their cars. It may be a viable solution here.

Anyone here an engineer that could explain why this might be happening?

I have a appointment with my indy shop to see if they can find the problem with my exhaust. If they find a solution or error on my part when I installed it, I will post it here.

**spy963** · 02-07-2017 04:03 PM

Subscribing.
I have the same problem this winter with my Magnaflow resonated xpipe in place of the stock baby resonators and no center resonator. Drone around 2200 rpm.

**Loe** · 02-07-2017 04:33 PM

so from what I've gathered after asking a few people (and it may be different from car to car, set-up to set-up), this vibration is independent of exhaust drone correct? Have you guys used a sound measuring app to get the frequency of when it vibrates the cabin? You can try and to change the pitch/octave of the exhaust to a higher frequency by introducing an extra non-resonated x-pipe to the mix to see if that resolves the vibration (which may subsequently reduce/eliminate drone in that area as well).

**xxdunnxx** · 02-07-2017 06:49 PM

Originally Posted by Loe

so from what I've gathered after asking a few people (and it may be different from car to car, set-up to set-up), this vibration is independent of exhaust drone correct? Have you guys used a sound measuring app to get the frequency of when it vibrates the cabin? You can try and to change the pitch/octave of the exhaust to a higher frequency by introducing an extra non-resonated x-pipe to the mix to see if that resolves the vibration (which may subsequently reduce/eliminate drone in that area as well).

You are correct. My system doesn't drone at all. It just has the vibration as others do. The pipes can be seen shaking at the specified RPM. I had resonators on with no change, leading me to believe it's the engine vibration leading to the exhaust vibration. All of this seems to revolve around the flex section. It seems to be around a 35hz vibration if I were to put a number on it. Most dampers I've found target that frequency. I have high hopes for the damper, but then wonder what it will cause as an effect of the rest of the system pre-flex joint. Because it is decoupled by the flex, the flex itself may take a beating in doing so.

When I get them in I'll update the post with my findings. I have to travel for work, so it may be 2 weeks until I get a chance to try.

**whiped** · 02-07-2017 07:03 PM

I get this issue only on cold starts until the pump purges its air.

Sounds like it is coming from directly under the rear passenger floorboard.

I don't get it at all after that. I could poke my head under the car and see what it is coming from but I haven't bothered.

**extratime** · 02-07-2017 08:22 PM

Originally Posted by Loe

so from what I've gathered after asking a few people (and it may be different from car to car, set-up to set-up), this vibration is independent of exhaust drone correct? Have you guys used a sound measuring app to get the frequency of when it vibrates the cabin? You can try and to change the pitch/octave of the exhaust to a higher frequency by introducing an extra non-resonated x-pipe to the mix to see if that resolves the vibration (which may subsequently reduce/eliminate drone in that area as well).

I can hear it when I'm in a stop and go traffic where you don't get above 5 -10 mph. I don't have any noticable drone. In reality, it's more of an anoiance then anything. Most of the time I forget about it. I didn't even make an appointment at the shop just for that. I happen to be having a rear sway bar and end links put on so I asked if they would look at it then.

**BDP** · 02-08-2017 05:11 AM

I've got the same issue mainly on deceleration at about 2000-1700 rpms. I have AWE resonated donwpipes matted to a AWE catback. The connections from the downpipes to the catback are horrible. They constantly leak no matter what I do. I'm to the point where I may just have them welded together. I've always contributed the downpipes to the vibration because of the leak, as the vibration feels like it's coming from directly below. It doesn't do it at any other rpm though...which is odd, just that specific spot.

**leahcim** · 02-08-2017 09:17 AM

I had a minor vibration during cold start. There is a bracket that is basically under the console of the car that can rub against the pipes. Put a couple of washers or spacers to prevent the bracket from hitting the pipe. Problem went away and now I have no vibrations at all.

**MrFunk** · 02-08-2017 09:22 AM

The vibrations is the downpipes.
The vibration exists even with the stock exhaust - it is just significantly reduced.
If you get the car on a lift and rev it up to around 1500 rpm you will see the downpipes resonating and causing the vibration - it's VERY obvious.
Vibration is worst in cold weather.

For whatever reason mine has virtually gone away - I think ever since I heated my garage.

**PSUGOLD** · 02-08-2017 11:24 AM

It is weird though, in the AM, even cold start, as soon as I shift into reverse to get out of the driveway it stops.

**Rex Wilkinson** · 02-08-2017 01:01 PM

AWE Touring with resonated downpipes on mine and I get that vibration as well. My local garage told me that one part of my exhaust sits very close to one part of the underside of my car (I forget which part) They suggested that I wrap that section with some heat wrap. I was actually having them look for a suspension noise I was having when I had the H&R OE sport springs on when they told me about that.

**Silverbullet S4** · 02-08-2017 02:40 PM

Same issue here. Everything has been triple checked front to back and retightened but still exists. Currently have AWE touring with non-res downpipes, but also did it when I had AWE resonated downpipes.

**fitzydude** · 02-08-2017 03:00 PM

Mine has a shimmy/rattle on deceleration around 1500-1900 rpms. I just assumed it was the fitement of my hacked up magnaflow.

**VeNoMS4** · 02-08-2017 03:03 PM

I have it on mine as well. I have the AWE track with stock DP. The vibration occurs during cold starts and subsides once the RPM goes below 1k idle. DSG trans as well.

**xxdunnxx** · 02-09-2017 09:38 AM

Maybe with the stock catback, due to the added weight, the system absorbs most of the vibration. With aftermarket, due to lightweight and geometry of it, it shakes more at the catback section.

**xxdunnxx** · 02-10-2017 01:04 PM

Small update: The weather pushed the temperature up to 50° and it was far better than usual. Temperature greatly affects the issue.

**MrFunk** · 02-10-2017 01:40 PM

Originally Posted by xxdunnxx

Maybe with the stock catback, due to the added weight, the system absorbs most of the vibration. With aftermarket, due to lightweight and geometry of it, it shakes more at the catback section.

Bingo.

As I said above. It's vibrating at the downpipes. I've investigated this at length and spent plenty of time under the car with someone revving it from above.
And as I said - it's more noticeable in the cold when components are more rigid. It's the harmonics of the exhaust vibrating at the downpipes - lighter aftermarket exhaust will have this more. Just consider it normal... It's only for a split second at very low RPM.

And yes - it's even there with OEM exhaust. Just far less noticeable. You can actually hear it from outside the car if you know what to listen for.

**extratime** · 02-10-2017 07:32 PM

Originally Posted by MrFunk

Bingo.

As I said above. It's vibrating at the downpipes. I've investigated this at length and spent plenty of time under the car with someone revving it from above.
And as I said - it's more noticeable in the cold when components are more rigid. It's the harmonics of the exhaust vibrating at the downpipes - lighter aftermarket exhaust will have this more. Just consider it normal... It's only for a split second at very low RPM.

And yes - it's even there with OEM exhaust. Just far less noticeable. You can actually hear it from outside the car if you know what to listen for.

Your right about this. Since the temperature has warmed up into the 50's around here, I haven't heard it at all.

**xxdunnxx** · 02-11-2017 12:05 AM

Originally Posted by MrFunk

Bingo.

As I said above. It's vibrating at the downpipes. I've investigated this at length and spent plenty of time under the car with someone revving it from above.
And as I said - it's more noticeable in the cold when components are more rigid. It's the harmonics of the exhaust vibrating at the downpipes - lighter aftermarket exhaust will have this more. Just consider it normal... It's only for a split second at very low RPM.

And yes - it's even there with OEM exhaust. Just far less noticeable. You can actually hear it from outside the car if you know what to listen for.

This is all true, but there's got to be a solution. It's obnoxious on my car at least having the whole car shake on every development as it hits 1900rpm in the winter. Likely these dampers will be it! We shall see when I'm back from California. (Depending on the snow up here in MA)

**eurotic** · 02-11-2017 04:36 AM

Originally Posted by xxdunnxx

When I get them in I'll update the post with my findings. I have to travel for work, so it may be 2 weeks until I get a chance to try.

Did anyone else get an immediate visceral response to those words?

**MrFunk** · 02-11-2017 06:40 AM

Originally Posted by xxdunnxx

This is all true, but there's got to be a solution. It's obnoxious on my car at least having the whole car shake on every development as it hits 1900rpm in the winter. Likely these dampers will be it! We shall see when I'm back from California. (Depending on the snow up here in MA)

Keep us posted.
Ever since I heated my garage I have not noticed the vibration... Best solution for me

**xxdunnxx** · 02-11-2017 07:17 AM

Originally Posted by eurotic

Did anyone else get an immediate visceral response to those words?

If only I didn't have to travel with work. By all means, if someone else wants to try while I'm gone and post here the dampers I mentioned the part number for are like 35 bucks!

**Acejam** · 02-11-2017 09:33 AM

Any video clips of this issue? It should also be noted that even a bone stock B8/B8.5 S4 vibrates quite a bit. Just start your car and stare at the bottom cushion of the passenger seat and you'll see it move. This is because the V6 is one of the most unbalanced engine designs out there.

**MrFunk** · 02-11-2017 10:20 AM

Here's a vid I took when I was chasing the noise down. You see him put his flashlight right on the downpipes and states it's somewhat normal.

**xxdunnxx** · 02-15-2017 08:55 AM

The dampers should be shipped out tomorrow and I'll be flying back on Monday! It may be normal and within the tolerances Audi allows, but it can likely be fixed!

**SportVier** · 02-15-2017 10:07 AM

Dampers? Dampeners? What are these things of which you speak?

Sent from my SAMSUNG-SM-G890A using Audizine mobile app

**xxdunnxx** · 02-15-2017 10:13 AM

Check out OP. Essentially they're a tuned mass that absorbs vibration at a certain frequency. Google exhaust vibration damper and they will show up.

**dave96gt** · 02-15-2017 10:42 AM

Not that this is a solution to aftermarket exhausts, but the statement within this thread "I wish one of the companies that makes the exhaust would do some R&D on this issue" is poignant such that Audi performed R&D on the stock exhaust to prevent such annoyances. In a simplistic manner, the aftermarket companies are reintroducing the constituents that Audi engineered out. I understand that the aftermarket company's optimization of fit / gauge of tubing / location of hangers, etc. will have a variable effect on drone and vibration, but maybe the Audi engineers "optimized" the exhaust performance / comfort / cost as a whole.