Npp exhaust
Race Director
Joined: Jan 2014
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From: Fulshear, TX
https://www.chevrolet.com/performanc...d-price/config
Included w/Z51. Standalone $1,195 option for base.
Included w/Z51. Standalone $1,195 option for base.
Melting Slicks
Joined: Aug 2000
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From: Early 2020 Z51 Coupe, Original Owner, Ahwatukee Foothills, AZ
Melting Slicks
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Le Mans Master
Joined: Mar 2001
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From: Omaha
2020 Corvette of the Year Finalist (performance mods)
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Interesting. I was already ordering black tips because I prefer the look, will be a nice bonus if they are a little louder. As an FYI, ordering black tips forces NPP order if people aren't aware (I was definitely doing NPP, but when configuring I happened to add black tips first and it automatically added NPP).
Race Director
Joined: Mar 2007
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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."
Keep in mind that a 3dB increase is noticeable. Those who have the GM Borla report that it is louder. It will also have a different tonal quality - that many find more pleasing. It is subjective though.
Melting Slicks
Joined: Oct 2005
Posts: 2,586
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From: Palm Beach Florida
That option has been out for a while now. You have to order the NPP. Then order the GM Borla upgrade. Here are measurements that have been posted by Borla in other threads on this forum. These are direct quotes, from a while back. There could be later information that I don't know about."Unfortunately we don't test for maximum dB level. We use test standard SAE J1492 to measure the volume of our exhaust systems.
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."
Keep in mind that a 3dB increase is noticeable. Those who have the GM Borla report that it is louder. It will also have a different tonal quality - that many find more pleasing. It is subjective though.
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."
Keep in mind that a 3dB increase is noticeable. Those who have the GM Borla report that it is louder. It will also have a different tonal quality - that many find more pleasing. It is subjective though.
Race Director
Joined: Mar 2007
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It is a GM specific model, neither the ATAK or S-Type. That is why there is a separate sound pressure level measurement in what I posted above. Based on the dB levels above, the GM Borla is louder than the regular NPP, but not as loud as the S, or ATAK. As I noted, the tonal quality is different from the regular NPP (according to forum reports). The difference in tonal quality can be as important as the loudness.
Le Mans Master
Joined: Mar 2001
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From: Omaha
2020 Corvette of the Year Finalist (performance mods)
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You're better off just ordering NPP, then if you don't like it, do an exhaust swap. That way you might be able to sell the stock NPP, and you should definitely be able to find an aftermarket exhaust cheaper than what GM is selling. Having to order NPP & the Borla, to only get the Borla seems a little crazy.
Race Director
Joined: Mar 2007
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The GM Borla exhaust used the existing actuators for both the AFM valves and the exhaust flow control valves, and has the supporting software to control the exhaust volume through the vehicle menu settings. Many other aftermarket exhaust systems also reuse those actuators, and would required the NPP to have been ordered. Some may be cheaper though, if that is what you want. If you dont want to control the volume, you can skip the NPP. Then get an aftermarket exhaust that does not have valves. It will loud all the time, if that is what you want. This will require the use of the AFM valve actuator simulators, however. The car will throw a code if it detects an issue with the AFM valves.