KJLive

I am curious. What are the best settings to get the most sound from the LT2 with the factory exhaust? I love the sound at starting, but it is too quiet while driving. I don't plan on installing aftermarket at this point. Just looking for opinions! Thanks guys!

Andybump

If you have the NPP option. In Z-mode or my mode, set the engine/sound to Track. In Z mode you can customize all the other settings if you want, so you can have a louder engine sound but otherwise everything else set to Tour if that is what you want. And you can also use Track Drive Mode - but you might not like that for normal street driving (I dont).

KJLive

Sorry! I should have specified that I do not have any upgraded exhaust option on the car. So I assume there is nothing to change?

Andybump

But you still see the setting right?(others who do not have the NPP have reported seeing the engine/sound setting). So, there is some evidence that the car pipes some engine sound into the interior, if you have the 14 speaker system that comes with the 2,3LT. No-one has ever reported being able to detect it. But its documented on the Bose website, specifically for the 14 speaker system at the link below - its called Engine Sound Enhancement.

If it is real - it may be that the engine sound setting controls the volume of the "enhancement". Again, no-one has ever reported detecting it, and even if is there, I have no direct evidence that its controlled by the engine/sound. I will point out though, that they could have named it "exhaust sound" but chose to name it "engine sound".

In any case, if it does affect that, the settings I suggested would still applicable.

https://automotive.bose.com/vehicles...vette-stingray

GP37

Since you did not get the performance exhaust, it will be super quiet. Your options are to buy an aftermarket exhaust, of get someones takeoff NPP exhaust for a few hundred and do something to hold the valves open all the time.

tadda

Since you don't have an NPP exhaust I think your only option is an aftermarket exhaust.

SpectreOne

Bottom Line: You bought the quiet version. You'll need to switch your exhaust. Members on here sell their stock NPP exhaust all the time for a pretty low price. Or go aftermarket but you'll pay quite a bit more.

KJLive

I really appreciate the reply. I will check it out!

sTz

If you don’t want to change or modify your OEM mufflers, then you could just go w/high flow cats, which will add some volume.

BigF6B

KJLive, I still have my NPP Exhaust if you are interested. PM Me... Thanks, Tony

topdown1999

Respose to Andybump. My 3LT with NPP arrived with a bad passenger door speaker. Bass would cause a noticeable rattle from the speaker. With nothing playing on the radio and the car idling in gear, I could hear the "engine" through that speaker. Both issues were gone after the speaker was replaced.

alekscpi

I'd recommend buying a takeoff NPP plenty on here going for under $700. Keep the values open and she will sound a ton better and you wont get any check engine codes.

JerryU

Don’t feel bad. My NPP with windows shut and roof on is also quiet! The only time I really hear my exhaust is at WOT. Have NPP set to Track. MY two C7’s were definitely louder.

The Corvette Chief Engineer said there are several reasons:

1. The short coupling between the headers and muffler compared to the C7
2. They worked hard to get low engine noise as it is close to your ear to ear. They even copied a Ferrari 488 trick of having the glass between the cabin and engine compartment twice as thick as the windshield glass.

We all wish we could get that “Bark” at start to come when we wanted. It is partly loud because of the rich fuel starting mixture to warm up the CATs quicker.

Frankly because of the very quiet cabin I’m not sure I would invest in another exhaust unless I sat in the car when driving. My car sound is actually not bad when someone else is driving (very seldom for me only at the dealer when the tech drives it away!) I never have the roof off and windows always up. If I have the car door open when I start in the garage it’s a loud “Bark.” Normally start with car door closed so not so much!

If you are considering spesn9ng several thousand dollars be sure to get one with well designed insulation. GM only approaves and dealers sell one- BORLA. They have several only one approaved by GM but I would consider any as some my be too lound for GM.


I would only get a quality system with well designed heat insulation as Tenneco who designed and builds the exhaust did,

ryanbrennan1009

Don’t pay any where near 700 for the Npp exhaust. I’ve seen them give away for free. Lots of examples for sale in the $250 range. But, the largest cost would be to install it, unless your pretty handy. It does require removing the back bumper. Expect to pay around $500 for install

JerryU

NPP is controls by a computer. No NPP no way to control the NPP butterflies to work. Sure you can buy them cheap from folks who installed and aftermarket exhaust. In fact most Borla require the electronics to install theirs.

BUT you could buy a used system and block the NPP butterflies open. You'll have about what folks like me have with NPP set to Track.

Andybump

Yes - the cold start strategy is pretty complex - details about it are scattered through the Service Manual - its not easy to piece together and summarize. But here is one statement about it. It seems to say a bunch of parameters are monitored, Timing is modified during the start up, and fuel trim bias is adjusted to keep the air/fuel ratio within a predetermined range.

"The catalyst must be warmed to efficiently reduce the emissions. The cold start strategy is to reduce the amount of time it takes to warm the catalyst. During a cold start, the engine spark timing is altered to allow the catalyst to warm quickly. This diagnostic monitors the following to build an exhaust energy model:
Spark advance
Engine airflow
Engine coolant temperature
Engine run time
Engine idle speed
Catalyst temperature
The actual model is then compared to the expected exhaust energy model. Fuel trim bias is used to keep the post catalyst air/fuel ratio within a predetermined range. This allows optimal catalyst efficiency under various operating conditions. The engine control module (ECM) constantly monitors how lean or rich the fuel trim bias is commanded, to determine if the fuel trim bias is greater than a calibrated amount."

JerryU

^^^^
For a gearhead like me, good info. Thanks.

For non gearheads the Bottom Line is you cannot duplicate the sound except when stating a cold engine!

SIDEBAR
Can't do anything with an engine today with a computer! The 850 Holley on the 8.2 Liter BB in my street rod gets a rich starting mixture to maintain spark with an electric choke. That gives a rick mixture and higher throttle opening until the engine warms up. I'm sure emissions are far more than EPA allows!

C6 MoneyPit

I would ride in a NPP car before you jump in. I have it and it is quiet in it's loudest mode - as Jerry said with the windows up and the top on you hear almost nothing unless you romp on it. It may be too tame for you if you are looking for an aggressive sound in the cabin.

Andybump

As you know, the Ford Model A allows (requires actually) me to independently adjust spark timing and mixture. I'm not sure what the Vette does, but the more bark-like sound (or shaply defined putt putts since its only a 4 banger) is with the fully retarded timing. It tends to quiet down as the timing is advanced, with the engine rolling un-evenly at idle if advanced too far.. I don't notice much sound change with mixture, but I do notice that going up a hill I need to make sufficiently rich to get full power. The worst is if I cut it off and it spits a bit of un-burnt fuel mixture into exhaust and backfires - in the garage its truly deafening. A bark upon stop instead of start.

combatninja

If the car is too quiet, grab someone's NP takeoff for free (plenty of people give them away) and try that out. If an NPP stuck in permanent "full open" mode is not enough, time to go aftermarket. Non-valved aftermarket systems start out pretty reasonable.