Tom Wilson
November 1, 2008
Coupled with a 3.31 rear axle without Traction-Lok, Explorer Express says its blown V-6 has no trouble besting stock Mustang GTs and can handle most bolt-on cars. After our boot around the block, we agree.

Horse Sense: To us Ford fans, Dave Vanek is the main man at Explorer Express. To Nissan types, he's The Z Doctor. Besides hot-rodding Nissans, he has been supercharging Ford V-6s in Explorers, Rangers, and Mustangs for a decade.

Passing a gas pump doesn't have the same thrill as passing a bottle-fed Camaro, but thanks to $50 fill-ups, it's getting so that fuel economy is more fun. As with any other maneuver, the more gas pumps passed, the more amusement had.

This is especially true of daily driven Mustangs. Sure, gas mileage isn't a concern for track toys and Saturday-night shakers, but daily drivers are another story. Punishing the wallet isn't fun, yet slugs don't work either. What's needed is a balance between performance and economy, meaning all the performance possible with enough economy to make the pain bearable.

Enter Dave Vanek. We're ashamed we don't cover his equipment as often as we should, although we've been reporting on his V-6 creations for nine years. It's all good stuff, but it's too balanced and real-world to get much ink with the over-the-top hardware built today. It's strange when "too real" is a problem, isn't it?

That excuse doesn't cut it when you slide behind the wheel of Dave's latest supercharging package for the 4.0 V-6 in the current S197 Mustang. While the entry-level Mustangs are fine runabouts in stock trim, Dave's X-Charger blower packs a torquey punch. It's enough to turn the V-6 into a mid-13-second machine at the dragstrip or, more importantly, a snappy hitter that outruns stock GTs on the street. Combine that realistic power with the V-6's lower purchase price, better fuel economy, and reduced insurance profile, and you have a fun car for the real world.

Since the goal isn't to beat knuckle-dragging V-8s or extract the ultimate power, and because costs count, Explorer Express [(757) 254-7025; www.explorerexpress.com] builds its blower kit around the Eaton/Magnuson MP90 Roots-style supercharger. The Eaton's lower cost, near-silent operation, and OEM longevity are true advantages, enough to offset the modest efficiency. Furthermore, since the rotor pack and gear cases are manufactured by Eaton and everything else by Magnuson, the unit is tailored for use as a 4.0 Mustang blower.

Bill Scott owns this silver X-Charger-equipped V-6 that Explorer Express used as a demo car during our visit. Besides the blower, Bill bumped up the visuals with some classy paint and body panels. He drives a truck to work and uses the Mustang as a fun weekend project car with his son.

Charge cooling isn't used, avoiding $1,500 to $2,000 or so in kit pricing, as well as the increased installation cost, weight, and underhood shoehorning associated with charge cooling. This means boost is typically limited to the single digits to avoid seriously heating the charge air. In a modest-boost, daily driver application where stock manners are paramount, it's the correct compromise. Screaming-high rpm, high-boost power isn't the goal, but rather a big torque hit off idle and carried as far as possible up the tach. That's what the Explorer Express kit delivers.

Associated hardware is nicely limited to only what's needed. A bypass valve is integrated into the system to retain fuel economy and avoid charge-air heating when off boost; larger fuel injectors are required, as are colder spark plugs. All of these items are included with the Explorer Express kit, along with the electronic tune, longer serpentine belt, mounting plate, and aluminum intake manifold, as well as the usual small stuff needed to mount the supercharger. Because the 4.0 V-6 uses the same fuel pump as the V-8 GT, the stock pump and fuel controller are more than adequate and require no attention.

Options are few. The X-Charger is offered in two levels: standard and high-output. The standard 4.0 kit is 50-state legal and includes everything needed to install the blower. Its characteristic feature is a stock Mustang GT airbox and mass air meter, along with the GT's inlet hose, which is ingeniously flipped 180 degrees to fit the V-6.

Mention a V-6 Mustang and this isn't the mental image that comes to mind. It is, however, fall-off-a-log easy with the X-Charger pumping up the torque. The smoke is for real; the hoodscoop is for fun.

For the seven states not requiring California emissions compliance, Explorer Express offers the high-output kit. It differs from the standard kit by replacing the GT airbox with an open-element air filter, an Explorer intake hose, and a slightly larger 4mm mass air meter housing.

Standalone options are aimed at those folks who must have all the toys and those counter-culturists who insist on trying to make a V-6 do a V-8's job. These parts include smaller blower pulleys and more aggressive custom tuning from BamaChips.

One item standard with every blower is a straightforward installation. The blower sits atop the engine-where all your buddies can see it-and is supplied with an Explorer Express intake manifold. The majority of the install approximates an intake manifold swap.

As a high-output installation, the X-Charger causes a net weight gain of only 45 pounds. Similar to the rest of the V-6 engine, almost every ounce of that is behind the front-axle centerline. Bill's coupe benefits from custom BamaChip tuning and puts down 304 hp to the rear tires.

At the front of the engine, a thick plate is added to mount pulleys and provides a nose support for the supercharger. The nose support is likely overkill, but it was suggested to Dave by Bruce Griggs to guarantee the blower and its belt loads don't compromise gasket sealing at the rear of the intake manifold.

No engine accessory is moved for the installation, nor are any holes drilled or brackets ground; there isn't even a need to jack up the car. The blower carries its own lubrication, so there's no oil plumbing to deal with. It's also not necessary to get into the fuel tank and install a second fuel pump. The result is a 6- to 10-hour installation, Dave says. As always, we're pessimists-or optimists with experience-when it comes to gauging installation times, so we'll stick to our typical "all-weekend" advice when tackling a job this size. That seems accurate for the first-time amateur, although we agree that rapid wrench-benders out there should be able to handle this in a day. Dave says with his repeated experience, he has the install down to five hours but that shops should quote eight hours. Individuals have reported anything from 7- to 17-hour installs.

In any case, Explorer Express includes a thorough installation manual that can be downloaded from the company's Web site should you wish to preview the work. Dave says the manual is nearly too step-by-step, but its completeness means he receives almost no tech phone calls.

Explorer Express experimented with several air inlets to its Eaton/Magnuson supercharger, finally selecting this parallel arrangement called the inlet extension. Its location and shape were chosen to minimize intake air heat absorbed from the exhaust manifolds, something it does 20 degrees better than earlier designs. Large 30-lb/hr fuel injectors mean there's plenty of fuel on hand for extra cooling.

We were able to give the silver coupe in the pictures the old burnout-around-the-block test drive, and we have nothing but good things to report. Driveability is stock, and the Eaton blower is its usual quiet self until called upon. You really have to listen for the blower at idle or cruise. When you romp on it, the blower screams like a banshee, adding to the fun. The power is exactly as if the engine were much larger; the hit off idle is instant, big, and stays with you until redline. It's a stronger feeling than the stock Three-Valve V-8 in the Mustang GT, meaning there is plenty of fun on tap. The high-torque personality is also a natural with automatic transmissions, a real plus with commuter cars.

We didn't get a chance to test any fuel-mileage claims, but giving the bypass valve allows the blower to essentially freewheel when not making boost. Explorer Express' statement that it takes only one third of a horsepower to rotate the blower off-boost seems in the ballpark. Dave says he gets 25 mpg on the highway, which also seems correct. Premium fuel is required.

As blower kits go, the standard Explorer Express kit is reasonably priced at $3,995.95. The cold-air intake is something we'd like to have, as it helps the blower breathe; that sets you back $200. From there, you're la carte with pulleys and tuning, so knock yourself out. For our commuting and errand needs, or even for a fun weekend machine, we recommend the standard boost first. We have so much fun passing gas stations that we don't want to stop for anything more.

Measuring 3/8-inch thick, the front mounting plate and supercharger front support is beefy enough for the job. Mounting this plate and the supercharger assembly are the only two major steps in installing the X-Charger. Maintenance is just as simple-the self-contained lube in the blower requires replacement every 100,000 miles.

Explorer Express is casual about power ratings. The company prefers to refer to rear-wheel power figures seen on chassis dynos, and it therefore rates the standard California-legal kit at 265 rwhp. Adding the freer-breathing intake of the HiPo kit brings power to 275 rwhp and 282 lb-ft at the tires, or about what a Three-Valve V-8 puts out. With more aggressive tuning and the 2.80-inch blower pulley, Explorer Express has seen just more than 300 rwhp. In all cases, the torque rises quickly and stays high across what Explorer Express refers to as the "torque shelf," rather than a curve.

These numbers illustrate typical efficiencies for a supercharged engine and reflect the V-6's standard-performance Two-Valve architecture. After all, the V-6 was never intended to be a cutting-edge performance engine. These numbers underline the intelligence of a simple supercharging system that keeps cost down while notably-but not outlandishly-increasing performance.

At press time, Dave reported that no one had gone into the 12s yet using a hot-rodded version of his V-6 blower, but he figures it is only a matter of the perfect weather, dragstrip, and driver getting together before that number is posted. It's better than expected for the combination, and Dave explains it as the blower and V-6's super-fast torque rise. The combination leaps to peak torque by 2,000 rpm and stays there across the tach, launching the better balanced V-6 car quicker than the typical Three-Valve V-8 GT. It's also what gives the blown V-6 its strong street presence.

When your V-6 packs this much power and torque, you're allowed to have red brake calipers. Explorer Express also includes a dash plaque to warn potential passengers.

Charge cooling has become nearly standard on Mustang superchargers, but it isn't found at all in the Explorer Express V-6 kits. Why? Because it isn't worth the cost or complexity at the moderate boost the kit makes.

Part of the situation is the lack of room between the 4.0 V-6's banks; there isn't enough real estate to package a typical water-to-air charge cooler and get the air into the engine. Explorer Express calculates it would require raising the supercharger so tall that a high-rise cowl hood would be required. That translates into a $2,000 charge cooler for 10 to 15 rwhp. At $133 per horsepower, it isn't worth the trouble.

Explorer Express reports that without a charge cooler, its standard kit discharges air at around 130 degrees; 150 degrees on a dyno or during other sustained loads. It's handled with increased fuel by way of the engine management computer, which monitors air-charge temperature by relocating the stock inlet air temp probe.

Explorer Express offers three pulleys and boost levels for the Mustang V-6 supercharger. We recommend the stock pulley as the most appropriate for the V-6 Mustang's fun mission and lack of charge cooling. If you have high-pressure hankerings and race gas at the track, smaller pulleys are available. Eaton blower pulleys aren't quick-change parts, so constant pulley swapping isn't advised.

Pulley
Diameter
Approximate
Boost
Remarks
3.00 inches 6-7 psi Stock Explorer Express pulley,standard kit
3.00 inches 6-8 psi HiPo kit (freer-flowing intake)
2.80 inches 10-11 psi  
2.60 inches 14 psi