[1]By this point, you may be familiar with the white C7 Stingray that we selected to install and test aFe’s Momentum [2], cold air intake system. As the aFe install was done before the exhaust install, we recommend you give it a read if you haven’t done so already.
For those unfamiliar with the car, this exhaust installation was completed on a 2014 Chevrolet Corvette Stingray [3], equipped with the six-speed paddle-shifted automatic transmission, and optioned up to the 2LT trim level. The car was completely stock except for the intake system mentioned above. The car has a few thousand miles on it, and is truly in mint condition, making a great canvas for installations and testing.
While those of us at Corvette Online have been extremely impressed with all of the performance aspects of the Stingray, we just can’t seem to leave well enough alone. It must just be that innate quest to improve our automobiles. While the intake enabled the C7 to breathe more efficiently, we knew we needed to get that air out, all while producing a great exhaust note.
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The Exhaust System
Brent Noward is the Marketing Manager at TMG Performance Products [5], the parent company to both CORSA [6] and Volant [7]. We had the opportunity to speak with Noward about the creation of an exhaust system for the C7 Stingray, and he was happy to share. “Development of the CORSA exhaust offering for the C7 Corvette was an extremely challenging and rewarding project. From start to finish the project took over seven months to complete and consumed well over 1,000 man hours.”
Noward continued, “Once we had moved from the prototype phase to production however, we were confident we had delivered a system that delivered on all of the expectations of a CORSA exhaust, but at the same time, we were anxious for our first Corvette install. The nervousness quickly dissolved however as heads began to turn and smiles began to cross customers’ faces every time their C7 rolled off the lift with a new set of pipes.”
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We were happy to hear such enthusiasm and care about their product, and decided that CORSA was the bet fit for this particular application. In consulting with the car’s owner, we decided to move forward with the CORSA three-inch X-Pipe (item #14761) as well as the CORSA 2.75-inch Valve-back, Sport exhaust (item #14764).
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Additionally, we were able to get two different sets of exhaust tips for the Stingray. One set being in chrome, and the later being a black chrome finish. We figured the chrome tips would be the winner considering the car has the factory chrome wheels to match. However, after double checking with the owner, he ultimately chose the black chrome as he plans to fit his car with black wheels in the near future, and preferred the contrast compared to the stock tips. After looking at both options, the consensus at Corvette Online was in agreement with the owner, they’re one great looking set of pipes!
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The Install
Luckily, Corvette Online has the BendPak XPR-10ALP [14] lift which made for quick work of the CORSA exhaust install. For those who have installed after market products before, you may be familiar with the frustrating times when things weren’t built the right length, width, and so on. This was far from the case with CORSA’s system, as you could tell time was certainly spent making sure that this was truly a bolt on system, no “home-modifying” necessary.
We lifted the car up to a workable level and began removing the plentiful number of bolts holding on the skid plate / chassis brace, exposing the majority of the central exhaust system.
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We were then able to remove the bolts at the forward flanges, as well as at the rear for removal. By lowering the front down first, we could then pull the factory unit forward, and allow it to fall freely from the car.
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The next goal is to fully remove the factory muffler system along with the pipes uniquely bent to route over the transaxle. To access this, you must first remove the rear bumper section, accomplished by removing bolts behind the rear tires, as well as removing the side inserts, reflectors, and license plate to access more bolts. Front this point, a few alignment clips will dislodge it and the rear bumper cover is now free. Remember to set this in a safe place on something soft to avoid any paint damage.
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You can now remove the factory exhaust tips as well as the two bolts which connect the muffler tabs together, located in between the mufflers. You can then remove the factory exhaust hangers enabling you to pull each muffler down and out with the attached pipe sections. At this point, your Stingray should be free of all exhaust components.
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The next step involves some minor cutting, we used a sawz-all, with a fresh, sharp, bi-metal blade. There is a metal spacer included in the kit which allows you to easily mark perfect cutting lines on both sides of the factory butterfly valves. We marked our lines with a permanent marker, double checked the line again with the included spacer, then made nice straight cuts (and don’t forget the safety goggles). After we deburred the edges we used the included hardware to refasten our pipes, valves, and set them in place over the transaxle.
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At his point we decided to install the CORSA X-pipe after taking the rubber hanger from the factory pipe and fitting it to our CORSA pipe. We fastened the front of the pipes, then supported the rear while we moved to the back of the car to install our new mufflers. After reinstalling the exhaust hangers and putting the two bolts through the muffler tabs, we loosely connected the mufflers and the back of the X-pipe to the exhaust pipes running over the transaxle. This enabled us to rotate the exhaust pipes and mufflers for proper fit and alignment.
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We then torqued down all of our lose clamps, making sure the mufflers were hanging evenly, and reinstalled the plate beneath our new X-pipe.
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After reattaching the rear bumper and trim pieces, we tried both the chrome and black chrome tips one last time for an aesthetics check, and again the black chrome won out. This concluded our installation process, which meant it was time for the dyno and a little seat time!
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The Gains
When looking at our Dynojet dyno (dynamometer) results, we are first going to look at the amount of horsepower and torque gained just from the CORSA exhaust system. In other words, our dyno figures with just the intake installed will be our baseline, giving an accurate reading of what the exhaust system produced.
With the addition of the CORSA Sport exhaust and X-pipe, the Stingray gained 19.7 hp. The peak horsepower was achieved at 80 rpm higher then with the intake alone. Additionally, the C7 gained 20.8 lb/ft of torque and was able to do so at 60 rpm less then its previous peak point.
[40]Before = 401.7 hp and 417.1 lb/ft of torque, After = 421.4 hp and 437.9 lb/ft of torque
When combining an air intake system with a stellar CORSA exhaust as we have here, we achieved an overall gain of 36.9 hp, now at a total of 421.4 hp; and 36.1 lb/ft of torque, now at 437.9 lb/ft of torque. We are on our way to getting our wheel horsepower figures to match that of the factory engine!
Without reverting back to the factory intake, we have no way of testing what this CORSA exhaust system would truly produce as the only performance enhancement. That being said, the CORSA system is very well designed and we wouldn’t be surprised if it still produced similar numbers.
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Driving Impressions
The 2014 C7 Stingray is one amazing platform, and it is certainly going to take some high-level engineering to improve upon it. From the factory, this car runs from zero to 60 mph in 3.8 seconds. Between the aFe air filter system that we installed before and the CORSA cat-back exhaust system, the 6.2-liter V8 really seems to have sprung to life.
The motor definitely seemed to breathe even better then it did with the intake system alone, and with almost a combined 10-percent increase in power, we felt like there was a performance gain you can feel in the seat.
Additionally, when we were able to hear the car from the perspective of somebody on the side of the road, we became even more ecstatic. The throttle blip from on-power upshifts just sounds flat-out mean, not to mention the high-rpm downshifts. Should you be in a position where you can briefly hear the car before you can see it, you have little doubt that there is a high horsepower, V8-powered machine headed your way. An impression that every Corvette deserves to portray.
Brent Noward had mentioned, “The difference in the exhaust note from the available C7 stock option is immediately noticeable and the CORSA system gives the C7 an aggressive exhaust note that matches the C7’s aggressive styling while maintaining a drone-free driving experience that customers deserve.”
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We also thought we should mention that we did do a quick listening test of interior acoustics. While cruising on the freeway we drove at various speeds in order to activate the “cylinder deactivation,” in which the car stops the fueling and firing of four cylinders. We were pretty shocked by how quiet the cockpit became, as if the engine had gone into hibernation, waiting to roar back to life. Per Noward’s mention, we also did not detect any droning which the owner really appreciates.
The Final Note
The owner uses this car as a daily driver and wanted to stay on the more conservative end of the spectrum as far as exhaust note is concerned. Because of this we opted for the Sport exhaust option versus the Xtreme system. Fortunately, we were still able to get a sizable power gain along with an awesome sounding car, all while maintaining a drone-free ride with an exhaust note suitable for a daily driver.
After driving the vehicle for about a week, the owner stopped by to tell us how much he was enjoying the car with its newfound power and sound.
Look for more C7 installs and testing coming soon!
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