Fortunately, a wide selection of cat-back exhaust systems are available on the market for the LS2-powered C6 (not to mention for the LS7-powered cars as well). One of the leading aftermarket exhaust manufacturers for some time has been Ohio-based CORSA Performance, a company that caters heavily to buyers of GM cars and trucks (in addition to offering systems for everything from Vipers to Ford trucks-and even boats!). The company has been selling a 2.5-inch version of its C6 exhaust for some time, and recently introduced a full 3-inch version for the Z06 (believe it or not, the factory Z-car system necks down to 2.5 inches at the muffler inlets). Never one to rest on its laurels, CORSA decided that LS2-powered cars could benefit from a bump to its Z06-spec tubing for even better flow capabilities than those the company already offered.
Enter the dual 3-inch RSC exhaust system you see here. Designated as PN 14171, the system carries an MSRP of $1999.99-with a "twin-tip" kit (with four total outlets) being available for an extra $100 (PN 14165). According to Ed Burgy, Automotive Product Manager at CORSA, "These prices are toward the premium end of the spectrum for aftermarket C6 exhaust systems; but taking into consideration our patented Reflective Sound Cancellation technology, 321 stainless steel construction, and lifetime warranty-in addition to improved flow, performance, looks, and sound-it is truly the only real choice for the Corvette." It's damn close to the same system CORSA sells for the Z06, the main difference being that this system adapts to the stock 2.5-inch cat pipes, then immediately opens up to its full 3-inch diameter-large enough for the gobs of exhaust flow we hope to be producing in the near future. Follow through the photo captions as we install and review this system-and be sure your subscription to GMHTP is up-to-date, because we've got loads more Corvette action to come!
Fuel and Air: Up In the Mix
Those of you looking to step into a cat-back system for the C6 Corvette may be worried about its effect on an LS2's ECM; after all, these newfangled engine computers are known to be a bit finicky and exhibit behavior different from control units of years past when engine modifications are performed. We were wondering this too, and so ordered up an Innovate Motorsports LC-1 Wideband Controller. This unit is capable of delivering and recording real-time readouts of AFR to your laptop computer. We'll have a more detailed review of this system and its installation in an upcoming issue of GMHTP (we'll be using LC-1s on several of our project cars).
The only thing preventing Innovate's LC-1 from being a true bolt-in product is the need to weld the O2 sensor's bung into the exhaust. The best location for the sensor is before the catalytic converter, as catalysts will throw off the air-fuel ratio reading slightly -you can see we're putting ours in the cat housing, as the Corvette's cast-iron manifolds mean there is nowhere else a bung can be welded upstream. And no, we're not welding a drill bit into the bung here; it's just making sure the bung stays centered over the hole we've drilled (do NOT weld the bung with the sensitive 02 installed into it!). | 
One of the few ignition-switched electrical sources we found on our C6 was, ironically, the fuse for the factory O2 sensors. Wiring the LC-1 was a simple matter of tapping into this as well as wiring three ground wires to two separate grounds (to help prevent interference). One of the grounds has a momentary pushbutton and LED installed inline to help easily monitor and calibrate the unit. Beyond this, weatherpak wiring runs to the sensor installed in the exhaust below, and two cables run inside the vehicle for easy laptop hookup. The unit was tie-wrapped securely alongside our Vette's fuse box. | 
Just ahead of the rear wheels, two clamps (one per side) hold the H-pipe to the over-axle pipes. Loosen them, then use some mojo to slide the H-pipe off the front. Again, GM has wised up in recent years and the days of standard muffler clamps and consequent crimped exhaust pipes are gone-making aftermarket exhaust installations a snap. With the H-pipe out, the over-axle pipes will rest atop the axle assembly. |