Let’s face it; the Gen V LT1 in the ’14 Corvette Stingray is a complicated animal. Variable Valve Timing (VVT), Active Fuel Management (AFM), Direct Injection (DI)—and plenty of other acronyms I can’t think of right now—sit beneath a metallic motherboard that looks nothing like last year’s valley cover. So a simple solution that bolts on and adds over 120 rwhp is like a breath of fresh air. Of course, “simple” is not an adjective that the Edelbrock engineers would attribute to their E-Force Supercharger Kit for the ’14 Stingray.
Adapt a C6 supercharger kit, they said. It will be fun, they said. Not so much. Internally, the supercharger is similar to the E-Force C6 (’05-’13 Corvette) kit. The Eaton TVS2300 guts we’ve come to know and love are inverted to blow up into the plenum, and then down through the intercoolers and into the runners. However, the air-to-water intercoolers use higher density cores that are more efficient, and have the benefit of a much larger heat exchanger and a pump that flows 40 percent more water. According to Rob Simons, Edelbrock’s Vice President of Engineering, the real key to the C7 kit’s design is that it uses modular runners that bolt to the heads [and blower housing] instead of being integrated like the C6. This design solved the packaging issues that, he says, forced GM to use the smaller 1.7L Eaton R1740 on the ’15 Corvette Z06. In fact, Rob says Edelbrock’s modular design will allow it to adapt this kit to the Z06, which affords larger rotors and intercoolers.
Externally, the differences between the E-Force C6 and C7 kit are even greater. Instead of using the factory’s 6-rib pulley system to drive the supercharger, the C7 kit uses a proprietary harmonic balancer with a dedicated 10-rib drive. The drive pulley bolts to the balancer like many aftermarket types, allowing the use of an overdrive pulley for more boost. The aesthetics of the supercharger were deliberately given a unique touch to signify that this kit is not simply an adapted C6 kit. This fact is even more apparent when you see how well the supercharger integrates with the factory equipment from the DI fuel system all the way down to the heat extractor hood and airbox. About the only compromise needed to take a ’14 Corvette Stingray from 460 to 624 horsepower is the loss of Active Fuel Management (aka DOD). This was necessary to dial-in the supplied tuning, and not considered a high priority among its customers. However, with custom tuning this may be rectified.
Just because the E-Force is on the market, that doesn’t mean Edelbrock isn’t still on the move. Certification is pending with the California Air Resources Board (CARB), and Edelbrock expects an EO number for the C7 by the time you read this story. In addition to the previously mentioned accessories and Z06 kit, engine dyno testing is also being conducted to reach the upper limit of the E-Force’s capabilities. The engineers say that 640-650 hp is about the extent of the factory fuel system, which is only a pulley change away from the 624-horse Stage 1 Street Kit. Edelbrock’s in-house 416-cid stroker with ported heads uses a COMP Cams camshaft with a redesigned fuel pump lobe to boost fuel flow. Using race gas, they’ve already hit 830 hp, with more room to go.
We first laid eyes on Edelbrock’s E-Force Supercharger for the C7 at the SEMA Show last November. Since the ’14 Stingray had only been on the street for a few months, it was one of the only boosted C7s on the show floor. At the show, Edelbrock stated that the C7 kit, like the C6, would be 50-state legal and come with a 5-year/100,000-mile powertrain warranty as delivered. With such confidence behind its product, clearly Edelbrock has put its share of engineering into the C7 kit. We couldn’t wait to get our greasy hands on it, so we hooked up with Redline Motorsports in Deerfield Beach, Florida. Redline is no stranger to the pages of Vette or to the E-Force family of superchargers, having installed quite a few C6 superchargers.
“We have been working with the team at Edelbrock since the introduction of the E-Force on the C6,” stated Howard Tanner, Redline proprietor. “From day one we have been impressed with the engineering and attention to detail. The systems have a very OEM factory design, which leads to maximum reliability, [which is] critical for our company’s reputation. Our customers love the appearance of the new system and most certainly the big, flat torque curve that this positive displacement supercharger produces!”
Our test subject is a seven-speed manual equipped Z51 model with dry-sump oiling. We’ll be putting the E-Force Stage 1 Street kit (PN 1570) to the test on Redline’s Land & Sea chassis dyno for some before and after comparison. Follow along as this Stingray adds some serious sting.
01. The Edelbrock E-Force Supercharger for the ’14 Corvette Stingray (PN 1570) is advertised to turn 460 hp into 624 hp—just a tick under the upcoming Z06. Kits are available for the dry- or wet-sump Stingray as well as with or without a tuner. An Eaton TVS2300 rotor package, air-to-water intercooler, bolt-on runners, and a dedicated 10-rib drive system are the principle components. Though the runners are more than half as short as the C6 kit due to packaging constraints, Edelbrock says the spark curve used with Direct Injection helps make up the torque.
02. Compared to the factory C6 ZR1 supercharger, the E-Force is inverted—placing the rotors at the bottom, which blow up into the plenum and then down into the intercoolers. The use of individual runners, rather than an open plenum, is another key feature of the E-Force that enhances torque. Note: the MAP sensor is not provided and must be reused from the stock manifold.
03. Many improvements in the air-to-water intercooler system were made over the C6 E-Force kit, including a pump with 40 percent more flow and a larger heat exchanger. The finish on the materials such as the reservoir tank is what makes the kit look factory.
04. Redline technician Nick Ward got started by removing the factory air intake, scoop, and air filter (leaving the airbox intact). Underneath, he had to remove the bellypan to make room for the heat exchanger and removal of the balancer.
05. After removing the engine cover and unclipping the wiring harness, the intake manifold simply unbolts and slides right off.
06. The low-pressure feed line is unhooked using a GM fuel disconnect tool (3/8-in).
07. The hard line (to the right) is unbolted and replaced with Edelbrock’s reshaped version.
08. Now on to the cooling system: the radiator is drained, all hoses are unhooked, and both the electric fan and radiator are removed.
09. Rather than completely removing the A/C condenser, it can simply be pulled out of the way and wire-tied to save time and money.
10. Edelbrock provides this template in the extremely detailed instruction manual. It simply needs to be cut out and taped up in the appropriate spot on the inside of the radiator shroud. These holes will be cut with a hole saw for the water lines on the heat exchanger.
11. Two squares were cut in the bottom portion of the radiator shroud (using another template) where the heat exchanger mounting tabs slide through.
12. Two holes must be drilled to bolt the top tabs in place, and then the A/C condenser can slide back in place.
13. To make room for the balancer, the steering rack and sway bar must be unbolted and moved out of the way. The work initiates topside by unbolting the steering shaft and the ABS module from the bracket. Below, Nick unbolts the sway bar brackets, but not the endlinks, just to rotate it forward and out of the way.
14. The ABS bracket is unbolted from the bottom and removed, and finally the rack can be unbolted and moved forward.
15. With full access, Nick uses a balancer removal tool to pull off the stock piece.
16. Edelbrock’s replacement balancer is pressed on, using the installation tool, until it’s between 2.4 and 4.8 mm from the snout of the crank to the face of the pulley (balancer bore). The final measurement was 3.6mm before torqueing down the balancer bolt, treated with blue Loctite.
17. The second piece of the balancer contains the 6-rib pulley to drive the accessories and a dedicated 10-rib to drive the supercharger. It has three bolts that must be torqued to spec.
18. After installing the 6-rib belt, Nick removes some of the water pump bolts to install the Edelbrock tensioner for the 10-rib belt.
19. The rack, sway bar, and ABS are installed before starting on the heat exchanger pump and lines. The pump has a rubber-isolated bracket to attach to the lower radiator support. Once the lines are connected, the radiator and fan can be reinstalled.
20. Moving topside, Nick scavenges the intake O-rings off the factory manifold to install on the Edelbrock runners.
21. The intake runners are installed with the provided bolts, treated with blue Loctite. Edelbrock says the narrow bolt pattern necessitated a two-piece design. A keen eye will also notice that the foam valley insert has been trimmed (for the new fuel line) and reinstalled.
22. It takes two sets of hands to lower the blower in place before bolting it to the intake runners. From here on out it seems like you are almost done, but it takes a painfully long time to fully button it up—especially if you are hovering over the tech’s shoulder with a camera.
23. The belt goes on immediately after installing the blower, using a ratchet to move the tensioner.
24. Since the MAP sensor had already been installed (on the bottom of the blower), bolting up the throttle body makes it complete.
25. The intercooler lines (feed and return) are installed and clamped down before bolting down the reservoir for good.
26. Edelbrock’s intake pipe is clamped down to the throttle body and is noticeably devoid of all the silencing baffles of the stock piece.
27. The rest of the hoses and wires are connected to look like stock. The plastic piece that connects the airbox to the intake (and houses the MAF) is reused, as is the airbox. Not shown is the high-performance air filter Edelbrock provides that Nick slyly installed when I wasn’t looking. No doubt this compatibility is the reason this kit will soon have a CARB EO #.
28. The “Supercharged” coil covers are a perfect mashup of OEM and aftermarket. Some assembly is required.
29. The supplied pulley made 8.5 psi in “hell’s sauna” (aka August in south Florida), which was good enough for 551 rwhp (SAE) on Redline’s Land & Sea chassis dyno (using Edelbrock’s tune). That’s nearly a 125hp gain! Most impressive, though, is the instant torque that hits 470 lb-ft practically at tip-in, and peaks around 4,500 rpm at 538 lb-ft. It doesn’t start to drop off until 5,500 rpm. Now, where’s that other pulley?