CT4-V Open exhaust valves without burbles/pops?

[maxm50]

Hey all,
I'm currently waiting for a new CT4BW to be built (while keeping an eye on used listings), so of course I'm burning time by thinking about what I'll do to the car when I finally get one. Unlike most other cars in my life, the answer here is "not much of anything". But, one thing that I really would like to change, if possible, is to remove the incessant burble/pops (or at least drastically shorten their duration) on the Track exhaust mode. I love the tone of the exhaust on Track, but I really hate that 10-second long series of pops and bangs any time you let off the throttle. It's borderline comical. A few burbles/pops is fun. 10 seconds of it is just annoying.

So: Is there any way to do either of the following:
- Reduce the duration of the burbles/pops on the Track exhaust setting
- exert manual control over the exhaust valves (so that I could put it in Sport, which has less burbles/pops, but peg the exhaust valves fully open)

All of this is based on the assumption that the "Track" exhaust noise setting simultaneously opens the exhaust valves fully and also changes the engine tune to create all those pops. I'm also assuming that the exhaust valves are not FULLY open in Sport exhaust sound mode. If either assumption is incorrect, please let me know!

Side note: is there any functional purpose to the burbles/pops? Do they keep the turbos spooled up or something?

 

[piranha971]

It's not about the exhaust valves. It's in the tuning. Don't overthink it. It's good as is. The car needs a little theater.

 

[1Evil55]

I love the burbles. You could always coast to a stop in neutral.

 

[LastGas]

@maxm50 the second 'loudest' exhaust setting has nearly the same valves open profile as track. But only very minimal pops and bangs and much less artificial noise from the speakers. Off memory the only difference in valves open is part throttle below 2500 rpm and in six gear.

Also the valves are either open or closed, there is no intermediate setting. I know it doesn't always sound like that in the car but that's due to the added noise from the speakers. The pops and bangs are purely for the theater and not functional.

 

[Sebring20]

yeah I leave the exhaust in Sport mode. Its valve open without the indigestion sound like in track mode. Also hate the burbles

 

[maxm50]

@maxm50 the second 'loudest' exhaust setting has nearly the same valves open profile as track. But only very minimal pops and bangs and much less artificial noise from the speakers. Off memory the only difference in valves open is part throttle below 2500 rpm and in six gear.

Also the valves are either open or closed, there is no intermediate setting. I know it doesn't always sound like that in the car but that's due to the added noise from the speakers. The pops and bangs are purely for the theater and not functional.

Thank you, Lastgas! This is the kind of answer I was looking for. Surprising to hear that the exhaust valves are binary! I thought they would be progressive like those on the Ford Mustang active exhaust.

 

[jcsperson]

@maxm50 the second 'loudest' exhaust setting has nearly the same valves open profile as track. But only very minimal pops and bangs and much less artificial noise from the speakers.

I thought I read somewhere that there is no augmentation from the speakers in the 4BW.

 

[mfcentex]

I thought I read somewhere that there is no augmentation from the speakers in the 4BW.

I read that the audio system only reduces noise from unwanted frequencies.

 

[brad.kize]

The burbles are one of the few complaints I have with this car. Surprised GM went with such a "boy racer" approach, I'm wondering if this is something that could eventually be disabled via tune. Similar to others I set the exhaust in My Mode to sport, since it's much more tolerable.

 

[brewski]

The burbles are one of the few complaints I have with this car. Surprised GM went with such a "boy racer" approach, I'm wondering if this is something that could eventually be disabled via tune. Similar to others I set the exhaust in My Mode to sport, since it's much more tolerable.

It would be a major reason to push me to get a tune. I'm content with the power stock

 

[blackeneth]

GM put a lot of time and attention to get those burbles. Fast forward to 11:56 in this Savage geese review of the Escalade V to see the ultimate in burble tuning.

 

[Roadhawk]

The burbles are one of the few complaints I have with this car. Surprised GM went with such a "boy racer" approach, I'm wondering if this is something that could eventually be disabled via tune. Similar to others I set the exhaust in My Mode to sport, since it's much more tolerable.

I don't mind the burbles in wide open and I think the engine/exhaust sound pretty good and have no real complaints. That being said the Corsa exhaust and those that Tapout has modded sound even better IMO....more aggressive befitting the sporty nature of the car.

Do I need it - probably not....but if it were just up to me I'd upgrade (and maybe will some day....also awaiting the AWE variant perhaps down the road at some point)...but my wife would absolutely throw a fit if I did so as she likes quiet....so I'll stand pat for now and I like the sounds enough that I can't wait till the weather improves so I can drive windows down and enjoy it more....burbles and all...

 

[Dirkbg]

In touring mode the Corsa exhaust is just as quiet as stock.

 

[piranha971]

Corsa with the valves open sounds decent enough. Its louder than stock but a bit too raspy. Stock sounds deeper.
With the valves closed Corsa sounds like a broken vacuum cleaner. It is horrible. It might as well be a valveless exhaust as I don't think anyone will ever close these valves. I think I've seen just that argument made by some folks that had it installed: no one uses closed valves. So if you feel that you need to retain this function......