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Discussion Starter · #1 ·
Expecting to be flamed for this, but the exhaust drone from my stock ATS-V 8A at low speeds is getting on my nerves and I'd like to some silencers or additional resonators to quiet it down. Is it safe to assume this will void the factory warranty? I've considered less invasive options like sound deadening or heat wraps, but those are either ineffective or cause other problems.

Serious responses please. I still love the car's styling and power, so no, I didn't buy the wrong car...
 

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It would, though technically they'd have to prove the modifications caused any issue that comes up.

Interesting you say it drones at low speed though. What mode are you driving in? After initial movement from a stop in Sport mode, the valves close and it's really quiet. If you're in Tour mode, it's already really quiet. Is this a 16? If it's any year but a 16 you can modify the settings so valves are always closed even in Sport or higher modes.
 

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As mentioned above, these cars with the stock exhaust are darn near silent when the exhaust is in touring mode... and even in sport and track mode with the valves open they're not very loud.

If you have a 2017 or later, go into the drive mode preferences and see what mode the exhaust is set to (you can customize it by drive mode.) Sport and Track mode for the exhaust will keep the exhaust valves open in the lower gears but closed in higher gears until the engine exceeds 3500rpm, while tour mode will keep the valves closed in all gears until the engine goes above 3500 rpm.

If you bought your car used, you might also want to see if someone pulled the fuse for the exhaust valves... if they did the valves will be open all the time.

You should visually check the valve function too; set the exhaust to touring mode, start the car, and then go back and look inside the inner exhaust tips at the valves... they should be closed. Then switch to sport or track mode and look again, they should be open.
 

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Discussion Starter · #4 ·
Thanks for all the info, I did the buy the car as a CPO (2018) and fairly certain the valves are unmodified as it's even louder when I switch it to Sport mode, but will do a visual check just in case. I would think such a mod wouldn't pass CPO checks either, but perhaps it's easy to miss.

It's almost always in full Tour mode (handles well enough, so no need for Sport/Track), and does quiet down in 3rd gear or so. But when starting the car and/or cruising along in 1st or 2nd, it's almost unbearable. I faintly recall the 6M not being as obnoxious at low speeds when I test drove one, so kinda regretting the 8A since I recall slushboxes having a tendency to drone more.

Perhaps it's all relative, and for most folks it's quiet enough and I'm really just getting old :(
 

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By default, the car has "startup rumble" active in all drive modes, where the exhaust valves are open during cranking and for the first 5 seconds or so after startup... not sure why GM programmed it that way for tour and snow/ice modes. IMO startup rumble should be on in sport & track modes, and off in tour and snow/ice modes. You can enable/disable startup rumble by drive mode, but only if you tune the CCM with HPtuners.

Also, cold starts are always louder than warm starts, because below a certain coolant temperature the ECM commands split-injection pulses to get the cats up to temp more quickly. When this is active the exhaust has a different tone that's louder than a warm startup where cat lightoff isn't active.

I don't recall the A8 car I test drove being any louder at low speeds than my M6 car... the exhaust is still pretty darn quiet in tour mode at low speeds. In my M6 car at low speeds I hear mostly transmission and engine noises, but no real exhaust note. Maybe double check your valves and make sure they're fully closing and that both of them are closing. You may have an issue with one of the valve actuators.
 

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Expecting to be flamed for this, but the exhaust drone from my stock ATS-V 8A at low speeds is getting on my nerves and I'd like to some silencers or additional resonators to quiet it down. Is it safe to assume this will void the factory warranty?
No, it will not void the factory warranty.
 

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Discussion Starter · #8 ·
After owning MT cars prior to this A8, perhaps it's completely normal and I'm just not used to the drone. Or perhaps the V6 soundtrack isn't as melodious as my previous V8's 🤷

I actually don't mind the startup rumble too much, but would prefer to eliminate it after driving off. Can the latter be disabled via HPtuners? I assume that would definitely void the warranty though, and I still have quite a few years left of it :(
 

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I was driving around in Tour mode for most of yesterday. It's whisper quiet. So you either have an exhaust problem, exhaust modification, or truly are sensitive to the sound. My wife's Outback is louder than this car in Tour mode, unless you punch the gas.
 

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2020 XT5, 2017 ATS-V M6,1968 Corvair, 1974 Corvette, 2003 HD Road King
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I would check to see if it has been modded previously. My 2016 A8 is super quiet in tour mode.
 

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Discussion Starter · #13 ·
So I tried looking for these valves but couldn't find them since exhaust fumes were coming out and I didn't want to get high off of them lol. But I'm almost certain they're functioning correctly since it gets noticeably louder in Sport/Tour mode. It also sounds like all the other stock ATS-V's on Youtube, so I'm just gonna chalk this up to my ears being too sensitive :-(

And since it was a CPO car, I'd assume/hope there wouldn't be mods, or at least obvious ones like exhaust work. Anyway, seems like a silencer/resonator is the only solution, so hopefully my local dealers won't refuse any warranty repairs as a result...
 

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I would think if you have a reasonable dealer, you should be fine. Talk to your service advisor and even have them perform the work.
 

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Ok, to be direct, you bought the wrong car. Based on the engines output level the exhaust needs to pass a certain amount of flow. When you start the car it goes through a higher RPM warm up for the cats. That increased rpm requires the car to allow the added exhaust flow so it opens the valves. The only reason for the valves is to make it quitter during times the added flow is not needed, below 3500rpm.

Anything you add that makes the sound quieter will also limit exhaust flow. You could line the whole exhaust with sound proof pillows and the sound will still be coming out of the tail pipes. I have the A8 and on the highway there is absolutely no drone or even any noise from the exhaust so I'm not sure what you're hearing. Do you mean when you accelerate? If so that's what a performance car sounds like, probably should have gotten the regular ATS.

Don't consider changing the exhaust valves so they close more or all the time because that will induce back pressure on the engine, which can cause misfires.
 

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Discussion Starter · #17 ·
I am starting to feel like I got the wrong car...had they offered a more subdued ATS V-sport with the 3.0TT that may have been perfect. But I still love how it looks inside & out 🤷

More to the point, my main complaint is the drone when driving away (slowly) from a stop. I don't mind the startup rumble as much since it quiets down again pretty quick. And it is fairly quiet on the highway as mentioned.
 

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If you keep it below 3500 rpm when you're driving away the exhaust valves won't open . I personally prefer the car in sport mode so that the exhaust valves are always open when it accelerating because I don't like the way the car transitions from quiet too noisy. To me that's irritating, I would rather hear the note of the engine the whole time.
 

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Discussion Starter · #19 ·
Saw this interesting tidbit from Borla re: their ATS-V catback: "There are several ways to adjust the sound level. You can obtain venturies, for example, from your retailer that you can place in your system to quiet your system."

Borla seems to be reputable enough, so perhaps this "venturi" thing should be safe and effective? I see some threads about it on Viper forums so can't be too horrible heh.
 

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Discussion Starter · #20 ·
I'll need to try the < 3500 rpm technique, but if I'm remembering correctly that's pretty much where I always keep it on local streets when there are passengers in the car (who have also complained about the drone 🤦 )
 
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