Popping and cracking and banging - Exhaust

[cadence_1]

I posed this question in another post but can see that it might have moved the topic off what was currently being discussed.

So it is best to post an original thread. Please read below if you have time and insight.

Thanks for looking!



I was wondering if someone can clarify something(a few things maybe).

I have a 14 RS7 now. Love the car. I installed the APR DP's from my S6 on there and they work fine. Planning on Stage 2 sometime next month. My question is one that I am sure I will catch a bit of flack for, but given AMS assertion of "improving on the exhaust note" with their DP's I wanted to pick your brains.

So.. I absolutely HATE the snap, crackle, ,bang, and pop of the sport exhaust on both the S6/S7 and the RS7. It just sounds... over done in my opinion I guess. I know most folks like this sound. And it seems this is the way all OEM's at least are tuning these exhaust for some reason. And to each his own. But I am honestly looking for something a bit more exotic vs just loud crackles and pops every time I let off the throttle. I hope you guys know what I am referring to.

In fact I like the sound of the AWE track exhaust and factory DP's on the S6 well better than the RS7 sport exhaust. But even that has the requisite "bang, boom, crackle" on decel. But what is funny is this sound seems to be engineered by selecting Sport mode and possibly (but not 100% sure) opening of the secondary valve on the exhaust. I say this because if I am in drive and put the car in manual mode and down shift. I dont get the cracking and popping. The car sounds pretty good on upper revs and high deceleration, but of course lacks volume and the "exotic" tone of an aftermarket exhaust when this is done and the valves are closed.

Now in the paragraph above (sorry so wordy) I reference a bit of uncertainty in whether or not the valves are opening because I dont think I get this crackly pop if I am not in Sport mode(whether in manual or not, no matter throttle input). But from my research and testing the valves open above 2700 regardless of what mode I am in. So I am confused on that, and where this stinking crackly pop comes from? Can I stop it somehow while still having a free flowing exhaust?

Basically, I am trying to find an exhaust that sounds a bit more like the AWE without all the hoopla of the cracking, popping, and banging. The DP's didn't make this cracking happen because the car did this with the factory sport exhaust. They made it louder.... sure. But do the AMS DP's get rid of this sound? Tame it in some way?

I tried searching for some exhaust clips with the AMS DP's and 4.0 engine. But all I see are the two AMS dyno videos. And the stinking dyno rollers are so loud you cant really tell.. haha.

Thank you all for any input. Sorry if this hijacks the thread at all, it just seemed as if it was a bit off original topic anyhow.

Thanks!

[Ze_Nardo6]

Downpipes do not rid the exhaust note of the pops and bangs. I will say the APR add a louder, more raucous tone over the AMS pipes. AMS are quieter and more toned by my ear. A few have had both on their car on these forums and would share that opinion.

From the research I've done and videos I've seen, the general theme is the louder your exhaust setup, the more pronounced are the pops and bangs. For instance, the Milltek exhaust...I've never heard so many pops and bangs.

I'm currently running AMS catted pipes to the Akra system (which I would say is more tame than most other systems, but not all). The pops and bangs are there (and I do enjoy them in moderation), but they are far more subtle now than they were when I was running a more open, louder setup

[Dasquade]

For what it is worth, and everybody their own taste offcourse, i made my tuner add the bang, boom craclke to my S6 C7 (prefacelift, facelift already has it in certain degree).
Not 100% sure but it is, afaik, some sort of anti lag and i suppose to a certain degree depends on the type of driving mode you in. My S and M does it, D almost nothing (even with my controlable exhaust valves open).
Might want to ask your 'future' stage 2 tuner for a custom adjustment if they do (i know at least 2 european tuners that does that).
Sorry for lack of info and details (tired and late...).
Basicly, yes, if wanted you can get it adjusted ;).

Can't help on the exhaust, running russian catless thermo DP's, milltek non res S6 version valved with CETE valve controler.
For what it is worth, just driven 1houre highways (EGT's +-770°C), came home and measured my DP's temps: 230°C (not sure what stock or other non thermo coated ones run of temps, but think mines are doing good for their price).

[cadence_1]

Thank you so much for the replies!

My contention is roughly the same in that I think it is "tuned" into the system. Not sure why Audi decided to make it so obnoxious (again my opinion) but I would like to get rid of most of it.

My stage 2 will be from APR but I may be able to talk them into working with me on the popping if I am lucky.

What is funny, is I really just wish it sounded like my old Ultracharged S4 w/AWE exhaust or simply the AWE track exhaust on the S6.

Hopefully we can make some end roads with APR. Hell.. they are back in the exhaust game again. Maybe there is some hope. :)



Does anyone have any vids of the AMS DP's they can send my way by chance? Stock exhaust, aftermaket. Whatever.. Just want to hear the difference.

Thanks!

[arrivalanche]

The noises that you are talking about are part of the tuning of the car. You cant make it not do it.

[Dasquade]

The noises that you are talking about are part of the tuning of the car. You cant make it not do it.

Granted i'm no expert and heck i forgot what actually creates it, but if my tuner and several others can 'add' it, i'm sure if tuner wants, they can reduce it. I have to admite, it took my tuner 3 tune files, before they had the wanted effect on my S6 (with my last stage 2 tune i asked to reduce it again bit as it was bit too much).
If wanted i can even prevent it but very very slightly keep the throttle pedal (might want to give it a try).
*if correct, anti lag/pops & bangs are created by giving itsome negative timing when thottle is in off position...

[pez81]

I'm pretty sure the exhaust has nothing to do with it popping and banging. It accentuates it definitely when you have a less restrictive exhaust system. But the earlier cars I don't think do this. Also on my 2016 in D it doesn't do it at all and I have the valves open all the time. It's only in sport mode. So my guess is it's over fueling in to the hot exhaust on overrun. Which is down to the mapping of the stock or tuned car. Custom tune could remove it probably of you wanted.

Sent from my SM-G920F using Audizine mobile app

[Ze_Nardo6]

OP, APR will not custom tweak your tune in an attempt to rid of the pops and bangs (they don't do "one off" tweaks for any end users cars really). In fact, I've yet to see a tuner in the States offer that type of adjustment. As Dasquade mentioned, a few Euro tuners have made that a priority.

[NardoRS7]

I think the pops and bangs are over done as well in Dynamic mode. It needs to happen only at high RPMs. In my opinion they should do them only open 4500RPM

[ryanlada]

On my S6 I have had both the EPL and APR tunes. The EPL stage 2 tune had significantly less exhaust crackle than the APR tune. I would say the APR tune increased this over stock and the EPL tune decreased the crackle from stock levels.

[Sam S]

OP sounds like you have a serious problem. I’ll be a good sport and try my A7 (without bangs and pops) for you RS7. Lol

[flyfishing]

On my S6 I have had both the EPL and APR tunes. The EPL stage 2 tune had significantly less exhaust crackle than the APR tune. I would say the APR tune increased this over stock and the EPL tune decreased the crackle from stock levels.

im just curious, but which tune did you like more and why? thanks

[ryanlada]

Ultimately APR. I can't say enough good stuff about EPL, they were great to work with and i would recommend either company to anyone really.
EPL has excellent customer service and response. I liked their flash at home delivery, it made it easy for me to pick a dealership close to my home and on my schedule. Ultimately i had issues (that i think) were related to the ECU software version their tune was based on. Even on the stock tune the car didn't perform well (felt alot slower than my stage 2 2011 S4 to my subjective seat Dyno) and it wasn't until i had my car in for a fuel system code that the newer factory revision was applied and i could feel a huge difference in the stock level performance (felt as fast as the stage 2 S4).
I switched to APR because they had a tuned version of the updated factory code and the tuned performance has felt a bit better. The downside is that now going to the dealer for service is harder.
The exhaust sound was definitely different EPL to Stock to APR. APR has alot more crackle than stock (i have the factory sports exhaust) and the EPL tune had significantly less crackle than stock. I personally like the noise so that was a plus for me. I think EPLs trans tune ran smoother in comfort mode as I still have some odd lurching with the APR trans tune after coming to a full stop (shift to first clunk). Ultimately both are good solutions in different ways so choose accordingly.

[FourRings115]

I'm pretty sure the exhaust has nothing to do with it popping and banging. It accentuates it definitely when you have a less restrictive exhaust system. But the earlier cars I don't think do this. Also on my 2016 in D it doesn't do it at all and I have the valves open all the time. It's only in sport mode. So my guess is it's over fueling in to the hot exhaust on overrun. Which is down to the mapping of the stock or tuned car. Custom tune could remove it probably of you wanted.

Sent from my SM-G920F using Audizine mobile app

Pez is correct. The popping is from an extra little bit of gas being sprayed into the exhaust to ignite. So this comes from Audi already programmed into the engine tuning. Changing the exhaust doesn’t affect the pops. That said, even with the “loud” version of the Milltek on my car (non-resonated exhaust), there is zero popping unless the transmission is in Sport mode or I change the driving mode to dynamic. My car is is loud in comfort mode when accelerating, but there is no popping on decel unless I am in Dynamic mode.

[BLKMGK]

Pez is correct. The popping is from an extra little bit of gas being sprayed into the exhaust to ignite. So this comes from Audi already programmed into the engine tuning. Changing the exhaust doesn’t affect the pops. That said, even with the “loud” version of the Milltek on my car (non-resonated exhaust), there is zero popping unless the transmission is in Sport mode or I change the driving mode to dynamic. My car is is loud in comfort mode when accelerating, but there is no popping on decel unless I am in Dynamic mode.

This is correct. I currently own and tune a different platform, Porsche 911 turbo, and when my car was initially tuned by someone else it popped, banged, and spat fire on deccell. Looking into the tables I found that fueling wasn't being cut off-throttle so fuel was still being sprayed like carbureted cars used to do in deccel. A few mouse clicks in the fuel map and this was 100% eliminated. Since folks seem to be finding that this occurs only in specific drive modes that points to the Audi or aftermarket tune doing it - maybe try finding someone who can custom tune the ECU to remove it? Most EFI cars turn off fueling on deccell to save gas but in sporty modes I can see them allowing it. Anti-lag is another kettle of fish, richen the mixture, lower the rev limit, and retard the timing - fuel burns as it exits the exhaust port and expands in the exhaust manifolds. Turbos spool right quick but the mixture will heat everything real fast, bang like crazy which can damage turbines, and you can kiss your catalytics goodbye! Mine does it when I click the e-brake up one notch and stomp the gas ;)

Hunting an S6, S7, or RS7 for a daily which is why I'm here getting educated but fuel tuning is something I know a bit about heh :)

[FourRings115]

This is correct. I currently own and tune a different platform, Porsche 911 turbo, and when my car was initially tuned by someone else it popped, banged, and spat fire on deccell. Looking into the tables I found that fueling wasn't being cut off-throttle so fuel was still being sprayed like carbureted cars used to do in deccel. A few mouse clicks in the fuel map and this was 100% eliminated. Since folks seem to be finding that this occurs only in specific drive modes that points to the Audi or aftermarket tune doing it - maybe try finding someone who can custom tune the ECU to remove it? Most EFI cars turn off fueling on deccell to save gas but in sporty modes I can see them allowing it. Anti-lag is another kettle of fish, richen the mixture, lower the rev limit, and retard the timing - fuel burns as it exits the exhaust port and expands in the exhaust manifolds. Turbos spool right quick but the mixture will heat everything real fast, bang like crazy which can damage turbines, and you can kiss your catalytics goodbye! Mine does it when I click the e-brake up one notch and stomp the gas ;)

Hunting an S6, S7, or RS7 for a daily which is why I'm here getting educated but fuel tuning is something I know a bit about heh :)

Good luck with your search! I have been a long time lurker on RennList- want a 997.2 cab 6MT. Just need a garage to keep it in!


Sent from my iPhone using Audizine

[schaNYC]

grass greener... have a pre face lift and wish I had pops/bangs!

[allenzhang215]

Pez is correct. The popping is from an extra little bit of gas being sprayed into the exhaust to ignite. So this comes from Audi already programmed into the engine tuning. Changing the exhaust doesn’t affect the pops. That said, even with the “loud” version of the Milltek on my car (non-resonated exhaust), there is zero popping unless the transmission is in Sport mode or I change the driving mode to dynamic. My car is is loud in comfort mode when accelerating, but there is no popping on decel unless I am in Dynamic mode.

I had the non-res milltek as well. Compares to the OEM exhaust, the milltek definitely pops more. In dynamic mode, very time my foot off the throttle, i will get the pops. I remember, with the OEM sport exhaust, even in Dynamic mode, you need to get certain RPM to get the pops. However, you are right, on comfort mode, no pops at all.

[elp_jc]

New to Audi, with an S6 here. Quick related question. Supposed you're in full comfort mode, when you select 'S' mode on the tranny lever, what exactly switches to 'dynamic' by doing that? Obviously the 'engine/tranny' mode, but anything else? I think the 'exhaust sound' also turns to dynamic, but maybe even something else. Just curious if somebody knows for sure. Manual says nothing about that. Auto mode doesn't seem to be a stand-alone mode, by the way; just switching from comfort to dynamic, with the possible exception of the steering, which reduces a bit of assist, but keeps the variable ratios. Am I right? Thx.