It does have the silver heat shield visible. Has goldish tint to it

 

Correct. I think I misread the comment as the mesh being silver too (was in a hurry when reading), but what I stated was still accurate. I probably could've worded it better though.

 

Also, the upgraded heat shield acknowledged for 2022 (probably due to muffler change)

 

GM is an avid sportscar race car builder with its successful C7/C8 race program where they must comply with noise restrictions.
I have prepared a spreadsheet explaining options and an explanation of the dB logarithmic scale provided in jpg format.
It makes sense that GM has reduced the sound of the GM Borla system to comply with sound regulations.

I chose Borla as their system is on other cars of mine. While I am not an exhaust analysis professional, My interpretation of the after-market exhaust manufacturers
are some can be classified as "prototypes" where a quick design may emphasize getting into the market quickly with a sound/weight package
while others may design a total integrated system with sophisticated engineering that mimics GM Engineer capabilities.

Sound is a simple word that requires a simple explanation of a complex subject I have tried to summarize below:

Sorry if I cannot get "go advanced" sequence organized properly.

 

GM Borla system has reduced sound (see Borla specs) and should not be louder as someone reported (
References to "touring" mean sound setting, not the Touring exhaust made for other cars

 

This is being discussed in several threads. Information provided by Ian@Borla about measured sound pressure in dB indicates that the GM Borla system will be louder than the stock NPP system by 3.7 db. And that should translate to a perceived increase in loudness of 23%. Here is some supporting data.

The information that was posted by Ian@Borla is as follows. These were posted in a different thread by Ian@Borla - in two posts.
"The Stock NPP exhaust averaged 86.6 dB in Touring mode and 89 dB in Track mode.
The S-Type averaged 92.4 dB in Touring mode and 101.3 dB in Track mode.
The ATAK averaged 100.9 dB in Touring mode and 104.4 dB in Track mode.
Using the same test standard, SAE J1492, the GM Borla system averaged 92.7 decibels in Track mode. It's only a bit more aggressive than the stock NPP exhaust."

And, as pointed out in a post (I think in a different thread) by Zymurgy, 3.7 dB is generally perceived to be louder by something a little greater than 23%, so the GM Borla system should be noticeably louder than the NPP system - and that is substantiated above by someone that has one.

The loudness factor of 1.23 (23%) increase in loudness results from tests where the volume of a single tone is increased by 3 dB. - But in the case of the Borla system, there may be more going on. Some who have installed the GM Borla system report being very happy with it. I believe its described as favoring lower frequencies, and the Borla website says they do some "polyphonic" tuning like a cord on an organ, to emphasize certain sounds. So not only is the sound louder by 3.7 dB, but I suspect that it has a different tonal quality that will affect the perception of loudness. And, while lower frequencies (at least a constant tone) are generally perceived as not as loud at the same pressure level, in this case I think the sound may be perceived as more powerful, more satisfying, and even louder (based on some of the reports).

Here is a table (that I also posted in a related thread) showing perceived loudness for increases in dB sound.

 

complex comparisons, both scientific
and supports my comment while including the GM unit
as we are both describing how much 3 dB means and in your illustration, 23% louder.

Many were trying to determine ATAK vs. S-type.
Our two lists make comparison more factual
and the polyphonic tuning should make this
Bass- baritone really sing!
It does for me, and already had a track session with comments
from the spectators that the sound was more European pronounced!

NPP 89dB track
GM B 92.7
S 101.3
ATAK 104.4

thank you

 

Deeplateapex & Andybump: Thank you for the technical analysis.

I want to add the GM-Borla to my GM Order Workbench, being completed at this time. MacMulkin tells me that the GM-Borla is unavailable at this time. They are being told that it is not being produced. Is that consistent with what others are being told? Or, am I being misinformed?

 

Borla "Touring" are quiet and not significantly louder than stock OEM for what it's worth... Happy Motoring!

 

Expect in the range of 8 to 12 horsepower increase with Borla’s System eliminates restrictions typically seen from stock systems caused by sound-deadening back spacers and provides an unrestricted flow path for maximum power output. Happy Motoring!

 

OK, so based on this thread, and other sources, I decided to go ahead and bite the bullet and order the S-Type Borla exhaust. I just hit the 'go' button with Paragon. We'll see how long it takes to get here. In the meantime I'm going to talk to my local Chevy dealer and see if they're willing to install it. I'd rather do it myself, but I'm concerned about the valve relearn procedure. If they'll do the install, along with the valve relearn, for around $500 I'll go forward with that.

I'll let everyone know how it goes from here. Wish me luck!

 

We have S Type and Atak in stock for anyone interested.

-Josh

 

good luck with the $500 cap

 

Birks was a year late to the game and still is having difficulty with product and delivery.

 

Yes, GM’s anything will be on the quiet side.

 

Too quite for me I’m afraid.

 

You will make Borla marketing Division very happy.

 

Well, you’re right about that.

Good news bad news. The good news is that my exhaust has shipped and FedEx is saying it’ll be delivered on Friday. Further good news is that my local Chevy dealer has already done this same install for another customer recently. They feel confident about it and are happy to do the install but quoted me $700-900. That was the bad news. But, I do have about $120 of Chevy rewards money that they’ll accept.

So, I now have an appointment for next Wednesday to get my exhaust installed. I’m going to do some recordings and dB measurements this weekend and try to replicate afterwards to document the difference. I may even post on YouTube.

 

$300-400 around here, depending on dealer.

 

Looking forward to your results! Getting the job done correctly, plus using some points, isn't a bad way to go. Glad your dealership is confident and experienced.