The supercharger wars are heating up in the 2010 Camaro SS ranks as a plethora of belt-driven boost makers have made their way into the market. This month GMHTP sampled the newly released Edelbrock E-Force supercharger system for the fifth-gen Camaro. Versions are available for both the standard LS3 and the automatic-equipped L99. We hooked up with five-time Pro Street champion and noted engine builder Pat Musi to test the E-Force supercharger. Musi's Camaro has less than 1,000 miles on the odometer and is 100 percent stock. In that trim, GM claims the LS3 produces 422 hp and our test Camaro rolled out 348 rwhp and 345 lb-ft of torque (SAE) on a Dynojet. We quickly realized the 348 rwhp is gobbled up by the fifth-gen's massive size. But that kind of power is a nice starting point, and with a little boost we knew the Camaro was capable of producing Shelby GT500-slaying horsepower.
The E-Force blower fits under the hood nicely and is easy to install for those who have experience working on cars. The supercharger is based on the Eaton Gen VI TVS 2300 rotors-the same rotor package that's used in the supercharged LS9 engine found in the Corvette ZR1. For those unaware, the Eaton Gen VI TVS 2300 features a unique four-lobe design with 160-degree twist and 140ci capacity. This design allows the rotors to be highly efficient with minimal air temperature increases and silent operation-until you lay into the throttle hard and the blower screams with rage. The TVS blowers are known for low-end grunt; not just a big peak torque result but also a very broad curve. That will help the Camaro get moving against its lighter competitors.
Edelbrock's engineers didn't just stuff the TVS guts into a case and let it rip. Instead, the company focused on a few key areas to help increase performance over other systems utilizing the same Eaton internals. One of the highlights of the system are the 12-inch long runners. Longer runners promote more torque because of the wave theory. The intake flows air into the cylinder head runners, and when the valve is shut that air bounces off the backside and reverberates back into the manifold. The longer the runner, the more stored up air there is available for the cylinder to ingest when the valve reopens. Street-worthy engines should utilize a longer runner length as it helps torque production at lower engine speeds. Race-oriented combinations require shorter runners to enable the engine to turn higher rpm levels and take advantage of larger cylinder heads. It is a balancing act that we could spend 100 pages explaining theories and such.
Contrary to popular belief, runner length does affect performance of the blower despite the notion of it putting constant pressure on the back of the valve. Rob Simons of Edelbrock broke down the benefits on long runners for this application. Simons explained, "it is true that there will be continuous positive pressure in the intake manifold while under boost, however, the magnitude of that pressure will fluctuate rapidly with every intake valve opening cycle; that can be observed by adding an instrument to the intake runner with a high-resolution pressure transducer and logging it at a high log rate. The resulting data will show the fluctuation in pressure due to the aforementioned wave phenomenon." Simons is the lead engineer of the supercharger project at Edelbrock and his résumé also includes work on the American-made Saleen S7 supercar.
In Edelbrock's testing, its design team found 12 inches to be optimum on the LS3 engine. Simons continued, "the trick is to tune the intake runner length such that the timing of the peak pressure and intake valve opening are coordinated at the desired rpm range. For the LS3 system, the 12-inch runner is tuned to take advantage of this resonance below 5,500 rpm, which is where our customers spend most of their time driving." The team tested several designs and Simmons shared with us some testing data from its work with runner lengths versus an open plenum, which is used by some other systems on the market. Edelbrock's LS3 test mule was set up with the two styles, its 12-inch runner system and an open plenum design. Utilizing the same TVS 2300 and identical blower and crank pulleys (to keep blower rpm range consistent), the test engine saw 2.5 psi less (under 5,500 rpm) with the Edelbrock long-runner manifold-but the airflow remained consistent between the two systems. The lower manifold pressure with the same airflow means a cooler intake charge temperature, which leads to more power. Another benefit of less pressure is the less of a load in turning the supercharger-remember it takes power to turn a blower. So the less power required to turn the supercharger to the same blower speed will equal more power to the rear tires.
The system is more than just a TVS blower and a set of long runners, Edelbrock incorporates a front beltdrive system with attention to superior grip. The team went to an outside engineering firm for its development. "The entire design was sent to a company who designs the front drive setups for the O.E. manufacturers, and they did an analysis of the design, made recommendations on pulley wrap, belt spans, idler bearings etc., to make sure everything functioned properly. As a result of this analysis, we incorporated a new heavy-duty automatic tensioner, which has double the force and double the throw of the stock unit. We also have excellent wrap on all of the drive and driven pulleys. Last, we use only Goodyear Gatorback belts for maximum grip. These design attributes ensure the maximum performance out of the six-rib belt drive setup," stated Simmons.
The boost is chilled off thanks to an air-to-water intercooler setup that is incorporated into the supercharger assembly. A front-mounted heat exchanger keeps the fluid cooled off, much like a radiator for the engine. Edelbrock includes larger fuel injectors, bigger fuel rails, a plug-and-play wiring harness to hook it all up, CARB-legal air intake assembly, and a handheld tuner with pre-loaded ECM recalibration. The kit is currently going through the CARB approval process and should be legalized by the time you read this. The 50-state-legal label only applies to E-Force systems installed out-of-the-box, including the supplied ECM recalibration. Edelbrock realizes there are those who wish to push the power to a higher level and offers a Competition kit that deletes some of the extra hardware and only includes the essentials. It is not emissions compliant but will offer unbridled performance from the E-Force blower.
Our test with the E-Force Street Legal kit pumped up the LS3 with a peak psi of 9.96 and a consistent 6-8 psi from the start of the pull (2,500 rpm). The resulting peak numbers were 506 rwhp and 480 rwtq (SAE)-a gain of 158 rwhp and 132 rwtq. All runs were made with 93-octane pump gas and the Edelbrock supplied ECM recalibration, which had a very safe air/fuel ratio that ranged from 10.5:1 to 11:1 through the entire run. If emissions legality is of no concern for you, then we are willing to bet that there is another 50-60 rwhp with full-length headers, larger exhaust system, and a custom tune. Add a smaller pulley and it might be time for a new short-block.
Two things that stick out in our minds with the E-Force system: its ease of installation and the broad power curves, particularly the torque results. This test was performed during the winter months in New Jersey so we didn't have a chance to run the car at the track. Based on the dyno results, mid-11s would be the norm with a set of sticky tires out back. The Mustang crowd better look out.