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Corvette C6 Performance Exhaust Systems -
Buyer Beware
As proud C6 owners we have been intently watching the dialogue and product
introductions surrounding C6 performance exhaust systems. We admittingly have a biased opinion on what exhaust sounds are good and not so good. One thing that we watch very carefully is the in-cabin resonance or
drone you hear in many systems when you are at highway cruising speeds (60 – 80 mph, 1400 – 2200 rpm depending on the gear). When we were kids, having noise all the time (including drone/booming/resonance in the
car) was pretty cool - we just turned our radio up louder. Now that we have gotten a bit older, we still want to sound cool at engine start-up and acceleration, but have no need for the booming sound that upsets our
ears (and needless to say, our spouses) at highway speeds.
Back in June we got a limited sneak peak at the C6 at GM due to our long relationship
with GM Engineering and Marketing Teams. We quickly learned that the C6 is truly an all new vehicle, with a new motor, producing difficult harmonic characteristics. Right off the bat, the source level harmonics are
5 decibels (dB) higher than the C5. Five dB may not seem significant, but it equates to the difference between the buzz of an electric razor and a child's scream. The challenge of tuning this exhaust, making it
sound cool, and having no in-cabin resonance, was confirmed by some of the GM engineers that worked on the stock system. The LS2 has a broader number of peak frequencies that result in booming. Said another way, the
amount of attenuation needed is over a wider bandwidth, thus there are more frequencies to tune.
Our acoustics engineers* are painstakingly working to specifically tune these
frequencies so all you hear is the deep, aggressive, and appealing tones when you want to hear them. The net result is the engine makes more horsepower and torque due to straight through design (you can roll a
billiard ball through our system), and produces a great sound with no interior resonance. We have yet to see a manufacturer match our performance on these four characteristics (+ HP, + Torque, no resonance, great
sound). Speaking of character, you will also experience some trailing throttle noise (or burble) on deceleration, so do not be surprised when your audience thinks you are driving a race car. We just think it sounds
cool.
Many exhaust manufacturers use a baffled or absorptive muffler to create performance
exhaust sounds. You may know these as glass packs or steel wool packed mufflers. The benefit is that they are easy and quick to build, and require little tuning, except for how much packing to put in. It essentially
becomes a packaging exercise, and thus these manufacturers are very quick to market. We have made the conscious choice to spend the money, time, and other resources to specifically tune out the "bad" frequencies and
keep the good ones. This takes extra time during the development process, thus it is rare that we are first to market. We do promise that we will be first to market a C6 performance exhaust with a non-resonating,
cool sounding, horsepower and torque enhancing system that looks great. Our C6 exhaust system will be worth the wait.
* Our acoustics engineers are retired NASA engineers, so in a way, this could be
called rocket science…
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