Michael Galimi
December 31, 2009

When someone mentions Edelbrock, your first thoughts are intake manifolds and cylinder heads. That's because Edelbrock has a long heritage of making some of the best aftermarket induction parts money can buy. The California-based company also sells exhaust and suspension components that are top-notch, but at the 2008 SEMA show, the famed supplier unveiled a new EFI supercharger system, dubbed the E-Force, for '05-to-present Mustang 4.6L engines.

The Mustang kit isn't the first for Edelbrock, as the company has been producing supercharger systems for carburetor-equipped engines for the past several years. Most people in the Mustang market never noticed them because the applications were brand-X specific. Nevertheless, the impressive E-Force EFI kit is hot and we've been waiting to get our hands on one.

Edelbrock might be somewhat new to the Ford EFI supercharger market, but it assembled a team of experienced engineers to build this product. The design starts around the proven Roots-style blower, but with many technological advancements. Edelbrock tapped Rob Simons, formerly of Saleen, to lead this project. He has worked on a variety of parts and vehicles for Saleen, including the S7 supercar and the company's own supercharger.

The E-Force group chose an Eaton Gen VI rotor package, otherwise known as the Twin Vortices System (TVS) 2300. The TVS rotating assembly is standard equipment on the '08 Mustang Cobra Jet drag car and Corvette ZR1. It features a unique four-lobe design with 160 degrees of twist and a 140ci capacity. According to Eaton, the lobe design enables maximum flow with minimal air temperature increases and silent operation. This supercharger rotor combination supersedes the well-known M122 Gen V series, which is found on the Shelby GT500 5.4L engine.

MM&FF has tested other supercharger systems utilizing the TVS guts with great success. The Roots-style supercharger tends to offer a snappier feeling in the lower-rpm range as it builds boost very quickly. While the Eaton's low-end prowess is well known, Edelbrock went after even more low-end torque with its unique blower intake manifold (intakes are Edelbrock's specialty after all).

The speed freaks at Edelbrock inverted the supercharger housing upside-down to reach their goals. This was done to incorporate 15-inch long runners-the longest runners of any current Roots or twin-screw-style blower available for Three-Valve Mustangs. Long runners promote low-end torque because they create a better ram effect at lower rpm, and this equates to improved cylinder filling.

At first glance, we thought of two other products that share a similar concept with the manifold design-the Saleen twin-screw blower and the C&L Three-Valve manifold. Both utilize the same concept of a bottom plenum flowing up over into the intake ports.

"The long runners and upside blower are very efficient," said Jim D'Amore of JDM Engineering. No worries on its massive size though, the supercharger fits under the factory hood, but you should check with Edelbrock if your Stang has a strut-tower brace. We know it clears the Ford Racing brace, but the braces with the three-point attachment (firewall and each strut tower) might cause a problem.

Edelbrock's Rob Simons had a lot of insight into the manifold design and long runner technology. He said, "The common myth has been that when you add a supercharger, it is no longer required to tune intake-runner length to the application. That is rooted in the fact that superchargers inherently provide a large increase in low-end torque on their own, and therefore it is not necessary to try to package a long runner in the manifold. While it is of course true that you can achieve large increases in low-end torque simply by adding a supercharger, this is not to say that the system could not be optimized by fine-tuning each aspect of the system's geometry."

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Why does a longer intake runner provide better low-end than a shorter one? Simons explained the concept as it pertains to a naturally aspirated combination, "As the intake valve closes, a pressure wave reverberates back up the intake runner. As that pressure wave reaches the plenum, it rebounds back toward the valve. If the valve happens to be open when the wave is traveling back down the runner, then air is rammed into the combustion chamber with greater momentum due to the inertia of the wave itself. The speed and frequency of the wave is much faster than that of the valve cycle, so not every wave can be taken advantage of, however, the longer the distance the wave has to travel, i.e. the longer the runner, the larger the wave intervals, and the lower the engine rpm at which the intake valve opening sequences with a multiple of the wave frequency. A shorter runner results in a faster wave frequency, and it is not until a much higher rpm at which the engine is able to take advantage of this energy source."

The same pressure wave reverberation occurs in supercharger applications as well. "Now it would be naive to assume that this phenomenon is completely unchanged in a forced induction application. The positive pressure in the manifold certainly has an effect on the wave behavior, however instrumented testing shows that the wave still exists. A pressure transducer located inside of the intake runner, and monitored at a high log rate, will capture the peaks and valleys in the boost pressure curve-due to this reverberating pressure wave. The benefit of this system optimization can easily be seen on the dyno. While a stock 4.6L Three-Valve Mustang engine has a torque peak at approximately 4,800 rpm, an E-Force supercharged Mustang engine sees its torque peak at only 4,200 rpm. Most competitive supercharger kits, utilizing short intake runners, likewise see a later torque peak of around 4,800 rpm," inserted Simons.

In addition to the long-runner manifold, Edelbrock also built a special cast housing to allow the lobes to be fed from the front-side, but also with it using a front blower-drive system. This design varies from other Eaton-based systems that have one or the other. If front-fed, the supercharger usually utilizes a jackshaft to spin a rear-mounted pulley system. Other TVS blowers use a front-driven setup but rely on the air to be fed on the backside, where there is a little room behind the blower to get a decent-sized inlet manifold between the housing and firewall. Plus, the incoming air has to make a 180-degree turn, which can hurt flow.

One part that Edelbrock includes is an 85mm throttle body, which is round for better packaging. The throttle body is typical with an electric motor for the drive-by-wire system employed on the S197 Mustang. The large manifold relocates many sensors and the fuel injector positioning. To remedy the plug connection problem, Edelbrock includes several wiring harnesses to make this a complete plug-and-play setup.

Once attached, the supercharger blows into a 110-square-inch intercooler before it passes through the 15-inch runners into the cylinder heads. The complete Edelbrock system is 50-state legal when installed out of the box. Like most Edelbrock products, it's proudly made in the USA.

The company sells a complete system, but we followed JDM Engineering as the New Jersey-based Ford performance shop bolted the Competition Kit to an '08 Mustsang GT with a five-speed manual transmission. The E-Force Competition system comes as a barebones setup so shops can add their own stuff. JDM chose to install its own fuel system and custom tuning. The shop uses SCT software, and D'Amore prefers to run the car on the dyno and then road test to ensure the tune is right for each particular vehicle.

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The company also added a Ford Racing dual GT500 fuel pump setup with a matching dual fuel pump driver module (FPDM). This setup is super-simple and fits like a factory-produced item. A set of eight 60-lb/hr injectors were added to ensure fuel delivery isn't a concern. Also included in this spartan setup is the Competition Inlet Kit, which features an open-air element and a PMAS MAF sensor. The basic Edelbrock kit comes with an optional 3-year/36,000-mile warranty, but the tuner-kit doesn't carry that option.

These mods were done because the customer wants more than the advertised 466 hp and 439 lb-ft of torque (at the flywheel) and 5 psi output. That equals approximately 410 rwhp if you use a rough 12-percent conversion for a manual transmission-equipped Mustang. JDM increased the boost by swapping the blower pulley from the standard 3.875-inch to a 3.250-inch. That brought the boost from 5 psi to a tire-scorching 14.5 pounds. "The boost went to 11-12 nearly instantly on the dyno, and then went up to 14.5 in the upper rpm range. The peak boost was due to the restrictive exhaust system," commented Jim D'Amore III. The results were an outstanding 519 rwhp and 489 lb-ft of torque. The elder D'Amore dialed in a mild 16 degrees of ignition timing for use on pump gas. The torque results caught our eye, and JDM's Shaun Lacko commented, "Jim III's yellow Saleen makes way more torque with the Edelbrock blower than any of the twin-screw combos-and they all have similar engine combos."

On-Track Testing The chassis dyno testing netted some awesome results, but we wanted to see how this car did on the quarter-mile. JDM is practically around the corner from Old Bridge Township Raceway Park (Englishtown, New Jersey), so we popped in for a few quick runs. Carlisle's goal was a 10-second pass with the near-stock engine and supercharger. Knocking off 519 rwhp was near enough to accomplish that task, but D'Amore faced an uphill battle due to the road-race-inspired suspension and stock clutch. The car did have a set of 3.73 gears to help it accelerate quicker.

For track testing, the 20-inch rear wheels were traded for OEM 17-inch Bullitt wheels wrapped in Mickey Thompson ET Street (26x11.50) DOT slicks (set at 16 psi). These are the same tires we have used to test everything from a 10-second Shelby Super Snake to a 12-second Two-Valve project car. The sticky compound, decent sidewall, and shorter overall height (than a stock tire and most 20-inch wheel/tire combos) helped this 3,850-pound Mustang stick to Englishtown's starting line and run hard down the track. The intense torque curve requires sticky rear tires, otherwise you will be left spinning.

D'Amore left rather mildly (3,000 rpm) on his first hit to create a baseline and see if the car would hook. The E-Force-equipped Stang launched with ease (1.89 60-foot time) as the tires spun out of the gate. The front end would barely lift as he stabbed the throttle and let the clutch out. D'Amore power-shifted the five-speed trans and the Edelbrock blower screamed to the finish line with an 11.78 at 122.4 mph.

D'Amore got more aggressive on the starting line after a brief cooldown. This time he left higher (4,500-5,000 rpm), knocked off a 1.73 60-foot time, and breezed through the lights in 11.41 seconds at 123.6 mph. That would hold up as the best pass of the day, but there is potential for quicker runs. D'Amore felt he needed more time to dial in the car, but the stock clutch definitely wasn't going to last as he hot-lapped it a few times. The big power started to take its toll on the clutch and he wisely said enough was enough. He made one last run, which produced a 1.63 60-foot, but the clutch was hot and he missed Third gear. D'Amore stayed with it and ran 11.97 at 119.

With the horsepower and torque results we saw with the E-Force system, it's evident that with a little more work this car will run in the 10s with its stock long-block, and that would equal one happy owner.

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