When the fifth-generation Camaro finally hit dealer lots in 2009, it was clear that GM had designed a winner. Its brawny lines turned heads on the street, and new buyers bought them in droves. GM also delivered the goods when it came to the powertrain. The stock 6.2 V-8 in the manually-equipped LS3 SS model pumps out an impressive 426 horsepower and 400 horsepower in the automatic transmission-backed L99 version. That bump in power from the fourth-gen days comes in handy since these new models are over five hundred pounds heavier. Despite the Camaro putting on some weight, many owners have been able to click off low-13-second runs in the quarter bone stock with both combos.
Earlier this year we picked up a 2010 Camaro SS/RS packing the L99 engine and 6L80E automatic transmission combo. We looked for one with the slushbox because of all the time we spend in bumper-to-bumper Chicago traffic. New to us, but already sporting 6,800 miles, we just had to take advantage of the late spring weather this past April and made a bunch of bone stock passes at Great Lakes Dragaway. So just a week after purchase and armed with solicited (and unsolicited) advice on how to run strong times with this car, it took only 7 passes for us to click off an impressive 13.15 at 106.77mph, cutting a 1.95 on the stock Pirelli tires. Subsequent track outings netted similar times, but none better than that 13.15. And predictably the car slowed down as we headed into summer. Low 13’s were easy when it was 65F, but mid 13’s have become the norm now that’s it’s routinely in the 90’s. And once it got warm, our invincibility turned into apprehension when a C6 or other quick ride rolled up on us. More power was needed.
We came up with a list of four mods that we thought would hopefully get our Heavy Chevy deeply into the 12’s, but keep it commute-friendly. An air intake always tops our list when we start digging into a new car, so we went ahead and procured one from the folks at Cold Air Inductions. Highly popular with the fifth-gen crowd, it’s easy to understand why. It’s very easy on the eyes and testing has shown it’s one of the best designs on the market. We also nabbed a ported throttle body from Bo White, well known cylinder head and throttle body porting expert. We then sourced a Powerbond 25% underdrive crank pulley from Scoggin Dickey Parts. With past combos we sometimes saw as much as a 10 horsepower gain just from this swap. Basically the smaller crank pulley will drive the accessories at a lower rate than stock by reducing parasitic drag. Turning to the exhaust, we considered a number of scenarios, including keeping the stock manifolds. But based on our past experience with LS engines, they’ve always benefited quite a bit from headers. We asked Summit Racing what they would run, and they suggested Kooks 1.75-inch long-tube headers and high flow catalytic converters. Thoughts then turned to running an axleback exhaust and replacing the factory “jerry can” mufflers, but we held off, curious on how Heavy Chevy would sound with the OEM H-pipe and mufflers and also how well it would dyno.
1. Somewhere under those plastic covers lurks 400 horsepower stock. The stock airbox is a compromise between performance and sound attenuation. Note the big air silencer. Stock it was sometimes hard to tell the car was running.
2. The stock exhaust features two sets of catalytic converters. Luckily the aftermarket makes high flow catalytic converters that not only meet emission requirements but they help free up some horsepower.
3. The factory exhaust manifolds do a solid job, but at the end of the day there is power to be made with headers and it would be great to gain some bottom end grunt.
4. Jim Moran dyno’d our Camaro stock, and here is the sheet. 314.95-rear wheel horsepower is in line with what we’ve read on the web. Check out the wavy dyno graph. Jim said it was so hot that day that the ECM kept pulling timing.
5. The folks over at Cold Air Inductions spent a lot of time designing this air intake system, and it shows. The tube is ceramic-coated inside and out to minimize heat transfer, and the air filter (their own design by the way) is housed in an insulated unit that does not allow any hot air from the engine or radiator to enter the inlet tract.
6. The Powerbond underdrive pulley is noticeably smaller than the stock crank pulley. One install trick is cutting the stock belts off rather than spending a bunch of time fussing with them. Besides we don’t plan to go back to stock. Some installers will move or remove the radiator for the install.
7. The Kooks long-tube headers and high-flow catalytic converters are made from 18 gauge, 304 stainless and will never rust, perfect for our daily driver Camaro. While we thought about running some shorty headers, it was ultimately too hard to resist the superior scavenging capabilities of headers like these. We’re looking for increases in mid- and lower-RPM power too as well as peak gains.