C8 Exhaust Sound: We Have Not Yet Heard It’s Potential Loudness

[John]

I was re-watching to the CorvetteBlogger April 27th video of the C8’s NCM Bash circular drive by, and heard something from a person who know just how loud the C8’s exhaust can be, knowing that from his own ears and comparing it to the C8’s sound in this video.

There was a top Corvette team person who said at the end of the video, “He kept that exhaust quiet.” This comment was from one who has first person, direct knowledge of what he C8’s exhaust loudness can sound like.

Who made that comment which we can clearly hear in the video? It was Jeff Strausser, Corvette Brand Quality Manager (in the blue shirt walking toward the camera).

Jeff made that comment that at 1:09 in this great CB video of the NCM circle drive through. He was referring to its brisk acceleration on the main road as it drove away. Yet, it was way quiet.

It will be so nice to hear how loud the C8’s exhaust really can be.

[brad66]

I like the fact that with the C7 you can adjust the exhaust note from quiet to loud. Glad to see that will continue with the C8.

On my 2007 C6, I had Corsa Extreme with a supercharged/cammed/heads/headers LS2 and it was really loud all the time. Sometimes it's good to be quiet but that wasn't possible with my C6.

[John]

My thoughts exactly. When we do a long interstate day, that is one of the rare times we turn out exhaust down. Makes it a nicer IOO. However, the rest of the time, ours s set to max loud.

[meyerweb]

Yep. My valves are always open, except on the highway or when leaving my house early in the morning (keep the neighbors happy).

[Fasttoys]

I love having the flexibility of changing the exhaust note. Loud when I want it and quite when I need it, the best of both worlds.

[JB]

Npp rules....sometimes you just want it subdued....early AM escapes.....and late night arrivals.....highway for long distances...and sometimes....you want it loud and crazy...

[Mobius]

NPP is a great option, and definitely a must-have on my C8.

I'll normally take the long way through my subdivision, and into an adjacent neighborhood to let the engine/tranny warm before heading out to my favorite roads.

I'll perform this warm-up in Tour Mode. By the time I switch to Track Mode (my preferred driving mode, to enjoy the syncopating sounds of the melodious exhaust), the exhaust has also warmed, and little moisture is left in the mufflers, helping to keep the outboard muffler tips clean.

[Boomer]

I keep my NPP in "open" mode all the time. I assume the C8's exhaust with its LT2 and a "reported" 530 HP will be louder than our base 460 HP LT1 C7s.

[Mobius]

I keep my NPP in "open" mode all the time. I assume the C8's exhaust with its LT2 and a "reported" 530 HP will be louder than our base 460 HP LT1 C7s.

it's difficult to say, as a lot of it comes down to the C8 exhaust and muffler design, but I suspect that you're right.

[Boomer]

it's difficult to say, as a lot of it comes down to the C8 exhaust and muffler design, but I suspect that you're right.

Yea good point. As a total non-engineer, I figure since the exhaust system will be shorter cause the engine is in the "rear" there will be less muffling of the sound. Also cause it will be tight back there with the engine and everything else, the mufflers will need to be smaller and less restrictive.

I think in addition to emissions, the tone and db level should be the primary focus for the design of the exhaust system.

[electroVette]

Guess I'm the odd one out here. If I'm driving in a subdued manner I want a quiet exhaust, but for spirited driving I want an even quieter exhaust so I don't draw the attention of police. A loud exhaust is yet another provocation to a police officer that could decisively tip his decision between a warning and a ticket.

[meyerweb]

Yea good point. As a total non-engineer, I figure since the exhaust system will be shorter cause the engine is in the "rear" there will be less muffling of the sound. Also cause it will be tight back there with the engine and everything else, the mufflers will need to be smaller and less restrictive.

Since I can say whatever I want, I think the tone and db level should be the primary focus for the design of the exhaust system.

Actually, smaller sometimes mean MORE restrictive. But GM spent a lot of time tuning the exhaust on the C7, and controlling the valves so even in track mode it quiets down at steady speeds of 35 mph and lower to pass the EPA's drive by sound tests, while opening up at higher speed and large throttle openings.. I'm sure they won't do any less for the C8.

[Boomer]

But GM spent a lot of time tuning the exhaust on the C7, and controlling the valves so even in track mode it quiets down at steady speeds of 35 mph and lower to pass the EPA's drive by sound tests, while opening up at higher speed and large throttle openings. I'm sure they won't do any less for the C8.

I think thats a 50 foot sound measurement distance from the drive by. Plus maybe a stationary throttle. Don't know for sure. But I'm sure my C7 would more than meet it leaving room for the C8 to "expand". Tire noise makes up some of it. I'd like to see three NPP settings with the third just meeting noise requirements.

[meyerweb]

I think thats a 50 foot drive by plus maybe a stationary throttle. Don't know for sure. But I'm sure my C7 would more than meet it leaving room for the C8 to "expand". Tire noise makes up some of it. I'd like to see three NPP settings with the third just meeting noise requirements.

I did a bunch of research on what the standards were back when people figured out that even in track mode the valves closed up at certain rpms. In testing, I discovered it wasn't a specific rpm, it was a specific speed. Then I found the federal noise standards, and the only federal requirement is a drive by at speeds of up to 35 mph. Some states may have a stricter standard.

Later, someone on another forum had the opportunity to ask Tadge why the valves closed at low speed in track mode. His answer was "because we wouldn't be legal if they didn't."

Let's see....

Here's my original write up: https://www.stingrayforums.com/forum...tml#post557121