You can pick your nose, but you can't pick the engine for your fifth-gen Camaro SS--those who opt for the automatic transmission get an L99 under the hood while a manual transmission-equipped ride gets the LS3. Don't get us wrong, we aren't coming from a negative angle, just that there are two V-8 engines currently available for the Camaro SS based on transmission choice. The L99 and LS3 are nearly identical save for a couple key components--namely the parts and pieces required for the variable valve timing (VVT) and components of the Active Fuel Management (AFM) system, formerly known as Displacement on Demand (DOD). Let the debates begin on which engine is better for your Camaro, but rest assured, both new generation small-block engines are powerful and an excellent platform for performance.
The L99 is a 400-horsepower engine while its fraternal twin--LS3--is rated at 422 hp. The difference lies in the valvetrain; as the short-block, heads, and intake manifold are identical. One small note is that the L99 does have slightly less compression than the LS3 powerplants. The L99 valves are heavier while the pushrods, lifters, camshaft, and cam phaser make up the rest of the unique components. The AFM is a simple concept that makes a V-8 into a V-4 by deactivating lifters using oil control, which in turn doesn't activate the valves and shuts down select cylinders. This technique is coupled with a change in fuel flow into the deactivated cylinders. It helps save fuel mileage, but there are drawbacks. The technology was actually introduced in the '80s, but poor electronics caused stutters and rough transitions while the cylinders were being turned on and off. For the most part, today's digital ECMs, however, have the capabilities of controlling the oil effectively and smoothly. Though the engineers decided that a manual-equipped vehicle would experience harsh transitions using AFM, so it was deleted from such equipped Camaros. The automatic transmission also has the benefit of electronic control to allow for smooth transitions when going from eight cylinders down to four.
Yes, some might be screaming and kicking that the automatic Camaro SS is down 22 hp, but don't count out the VVT side of the L99. The camshaft can be advanced or retarded while the engine is operating, a feat that allows for excellent low-end torque, but as the RPM rises the camshaft timing is retarded and the engine breathes easier in the upper RPM ranges. Traditional fixed camshafts don't allow the benefits of both advance and retard conditions. East Coast Supercharging (ECS) of Cream Ridge, New Jersey, has been on the forefront of the LS wars since the engine was introduced many years ago. As many traditionalists are looking to swap out the VVT capabilities, ECS has embraced the technology by offering several upgrade packages.
"There comes a point where VVT should be eliminated, but in the case of many street cars, keeping it in place is a nice feature. It also saves a customer money because a VVT-modification package is cheaper than converting to an LS3 cam setup," says Matt Sorian of ECS. Matt Craft of Texas Speed and Performance expanded a bit more on the benefits of a VVT-style camshaft, "VVT allows us to change camshaft timing by grinding the camshaft with a lot of advance in the camshaft and slowly pulling the advance out as RPM increases. The result is you can get the best of both worlds. Instead of being limited to 4-degrees advance, for example, you can run more advance and then slowly pull it out through the entire RPM pull. The result is a healthy power gain in the lower and upper RPM range."
The ECS gang modified Ralph Fontanez's '11 Camaro SS with a Texas Speed and Performance VVT camshaft kit to prove the L99 is worthy of modification and not to be discarded for a fixed camshaft design. The car began in bone stock trim and produced 345 rwhp at 5,300 rpm and 355 lb-ft of torque at 4,400 rpm. The addition of a Cold Air Inductions intake system and ECS tune netted 363 rwhp; Doug Ring of ECS recalibrated the ECM (using EFI Live software) by tweaking the air/fuel ratio, adding some timing, and a few other little tricks. After a strong and consistent baseline, the ECS group brought the Camaro back into the shop to undergo the camshaft upgrade.
A late addition to the agenda was a complete American Racing Headers (ARH) exhaust setup to further take advantage of the camshaft upgrade. The ARH box included long-tube headers (17/8-inch primary tubes and 3-inch collectors), 3-inch X-crossover-pipe with catalytic converters, and 3-inch after-cat exhaust system including the company's own mufflers. The exhaust modifications were meant to complement the Texas Speed and Performance camshaft package making the L99 modifications a well-rounded package of better air ingestion and exhaling of the spent gases. We knew the entire list of changes was sure to bump the naturally aspirated horsepower significantly, and when the ECS chassis dyno stopped spinning, our mouths dropped. How does 98-rwhp gain over stock sound for said modifications? The final result was an outstanding 443 rwhp along with an even idle that sounded good, but not obnoxious.
The Texas Speed and Performance camshaft package goes for around $740 and allows the use of the stock AFM lifters. This comes with its limitations as Craft explains, "AFM is another item everyone is constantly discussing. The AFM lifters are a very limiting component on the L99 engine. These lifters, realistically, only allow about .500-inch lift before the guys at Comp Cams have started seeing failures. The AFM friendly camshafts require considerably less aggressive lobes to live more than just a few thousand miles." The limits are why Craft and his staff have spent considerable time and efforts designing and testing camshaft profiles. It has led to an effective camshaft design, but the downside is the company keeps the statistics and lobe shape a secret. The only info we have to share is that the duration is in the 220-degree range--anything under 230 degrees of duration doesn't effect piston-to-valve clearances. The milder camshaft design is said to be approximately 15 hp less than a more aggressive lobe (not compatible with AFM lifters) with the same specs as the cam we tested. Texas Speed and Performance also offers cam kits and AFM/DOD Elimination kits for easy swaps.
High-tech valvetrain or not--adding a properly designed camshaft will increase horsepower and the tried-and-true way of long-tube headers and larger exhaust whisk it away just the same as it always has done.