We first sampled a 2010 Camaro SS six-speed car in the September 2009 issue as Howard Tanner of Redline Motorsports (Schenectady, NY) brought his car to Englishtown Raceway Park for some quarter-mile fun.
The Camaro banged off low 13-second runs regularly with a best of 13.09 at 110 mph. On the chassis dyno, the LS3 power didn't disappoint and spun the drums to 377 rwhp and 370 lb-ft of torque, an impressive feat for a factory stock ride, but Tanner knew there was more lurking in the 376ci engine (6.2L). After the track day, Tanner invited us up to his shop to check out the first slew of modifications for his 2010 Camaro.
Late-model performance has a few mainstay modifications and Redline dove right into the fray with an ECU tune-using EFI Live software-and a cold-air intake kit from Late Model Racecraft (LMR). The new Camaro comes pretty close in the tune department, but a custom tune definitely helps. The biggest gains are due to the reduction of the torque management parameters from the factory. Torque management is the annoying segment of the program that pulls power away from the engine during certain driving scenarios-power-shifting being one of those parameters. The computer will sense load on the engine and pull back the throttle blade. Essentially, GM gives us 430 horsepower, but won't let spirited drivers experience it. While Tanner fiddled with the laptop to modify the tune, the guys in the shop bolted on a LMR cold-air inlet system to get fresh air into the potent LS3. The air-filter is a high-flow piece that feeds a four-inch inlet pipe that leads to the throttle body. These two simple mods brought output up to 389 rwhp-a gain of 12 rwhp from a couple of bolt-ons that take an hour to install.
After the basic computer tune and inlet modifications, we decided to open up the exhaust with a set of American Racing Headers (ARH) 1 7/8-inch full-length headers and three-inch X-pipe. We opted to get a set of high-flow catalytic converters to keep our test ride emissions compliant. Tanner chose to have Swain Tech coat the headers for protection and performance. The factory exhaust is restrictive and it's comprised of a pair of exhaust manifolds that dump into a mid-pipe system that has four cats in place. After it gets through that restrictive setup, the exhaust runs through a pair of resonators and finally into a set of huge (and heavy) mufflers. Plans were to replace the after-cat at this time, but unfortunately it didn't arrive in time for the install.
We have to caution, the primary tubes can be perceived as a little large for a stock engine, but we chose the 1 7/8-inch tubes because we were changing the camshaft right after we bolted on the exhaust. On the dyno, Tanner needed to make a few tuning adjustments for the efficient exhaust system. "Before the headers, the engine had a little detonation. With the same timing curve and the headers installed, the engine didn't see any knock. The headers helped cool down the combustion chamber," commented Tanner after making a few dyno pulls. The Camaro was now throwing down 416 rwhp and 420 rwtq, a gain of 27 rwhp over the factory exhaust. Our assumption is that a smaller header will help the Camaro make more, but 416 rwhp is really impressive and acceptable in our book! All told, our Camaro was producing 39 rwhp more than stock with the Redline tune, LMR cold-air intake, ARH headers and X-pipe.
The guys at Redline are well versed with the LS3, and Tanner wanted to make one more modification-swap the camshaft. The stock camshaft is a healthy one as it boasts 0.551/0.522 lift on the intake and exhaust side, respectively. GM gives the LS3 duration of 204/211 degrees at 0.050-inch lift. As good as that cam is for a factory piece, the LS3 heads flow enough air that a larger stick will do better. Navigating through cams can be tricky as every company seems to offer something for LS-based engines, most of which are not appropriate for the rectangular-port LS3/L92-style heads. The range of profiles runs wide from mild to wild, just know what you want before you order an aftermarket bumpstick. It is easy to get caught up with large numbers and the car's driveability will be greatly affected.
"The car is heavy. We didn't want to have a dyno queen or a car that surges, bucks, and doesn't drive nice. So we went with a cam that was more conservative," commented Tanner as he opened the Livernois Motorsport box. He continued, "we know what works with these engines. We can make 500 rwhp with the cam change and headers. We've done it with the Vettes. But those types of cams have characteristics that aren't desirable in a 3,800 to 3,900-pound car with stock gears and tall tires. This cam is very conservative-I cannot stress that enough." Clearly, Tanner didn't want to lose his low-end power only to gain a big dyno number at a high rpm as it would make the car sluggish around town and in the low rpm range.
Tanner worked with Dan Millen of Livernois Motorsports to come up with a profile that fit his goals for this project. The bumpstick of choice yields 0.590/0.600-inch lift, 230/236 degrees of duration, and a 112-degree lobe separation with a matching set of dual valvesprings from Livernois. As the result the Camaro experienced a 30-rwhp gain-not bad, but also not what LS-lovers are used to seeing. We suspected the stock after-cat to be the culprit, and Howard confirmed this when his exhaust finally arrived. Nevertheless, the cam change resulted in total output of 446 rwhp and 430 rwtq-some 69 rwhp over the baseline horsepower. The torque shows healthy gains through the entire range, meaning this Camaro will be snappy on the street and not just a dyno queen.