In this era of 420hp GTs, it's difficult to believe there was a time when a 390hp Cobra was the king of the Mustang hill. However, in many ways, the '03 Mustang Cobra was the spiritual beginning to the current era of high-powered 'Stangs. Our memories of first dumping the Terminator's heavy clutch pedal and unleashing the Eaton-supercharged Four-Valve 4.6 are still vivid. It was the car that delivered so many things that enthusiasts demanded for years: a six-speed manual, a supercharger, and even a nod to the wine-and-cheese crowd with an independent rear suspension. In short, it was one for the ages. Little did we know then that 390 hp and 390 lb-ft would seem weak by comparison. My how times have changed. However, one benefit of ever-increasing technology is applying it to older Mustangs.
Terminators have long loved supercharger upgrades, but heretofore there hasn't been a Termi TVS supercharger option. Eaton's Twin Vortices Series superchargers have proven their efficacy on GT500s and Coyotes. At the forefront of the TVS revolution is VMP Tuning, and its 800-plus-rwhp '07 GT500 and its 9-second '11 GT. Both cars were boosted by the trusty TVS. "After overwhelming success with the VMP TVS on the 5.4-liter GT500, it only seemed natural to go back and apply the technology to '03-'04 Terminators," explained VMP's main man, Justin Starkey. "While the cars are much older, stock unmolested cars pop up all the time with mod-eager owners." With such great results on those cars, Justin decided to offer a TVS for the Terminator. He engineered a bolt-on upgrade package.
"The VMP TVS is the first 'OEM-style' aftermarket blower ever produced for the '03-'04 Cobra. We started with an a new design based on OEM CAD data, then tooled a one-piece housing to bolt up to the factory lower intake," Justin added. "There is no adapter or intermediate plate, essentially making it just like an OEM blower in terms of fit and finish. This makes the blower easier to install and service, more durable/rigid, and less prone to vacuum leaks." That sounded pretty good to us, so we visited the VMP shop to see how this blower bolts on and what it puts down.
Horse Sense: Best known for its GT500 and now Terminator TVS upgrades, VMP Tuning also offers pulley and tuning upgrade packages for all Roushcharged Three-Valve 4.6 and Coyote 5.0 applications.
VMP customer Jeff Smith's...
VMP customer Jeff Smith's Competition Orange '04 Cobra served as a test bed for the VMP Tuning TVS supercharger.
Finding a bone-stock Terminator...
Finding a bone-stock Terminator is like going on a unicorn hunt. Fortunately, Jeff's Cobra was basically stock save for a smaller supercharger pulley, a Steeda CAI, and a custom VMP tune.
Without disconnecting the...
Without disconnecting the fuel line, Bobby loosens and removes the fuel rail and injectors. He swings the rail out of the way and removes the stock injectors. Larger squirters are necessary for the boost produced by the VMP TVS.
Positive-displacement superchargers...
Positive-displacement superchargers loathe inlet restrictions, so VMP designed its Termi TVS (left) with an ample inlet. As you can see, the stock M112 blower is not graced with a free-flowing entry.
After removing the belt, VMP's...
After removing the belt, VMP's Bobby Williams wrenches off the EGR connection. As most aftermarket supercharger options for the Terminator forgo the EGR circuit, Justin decided to follow suit with the VMP TVS. This improves performance, simplifies the install, and cleans up the engine compartment.
Removing the supercharger...
Removing the supercharger from a Termi is a bit more complex than doing so on a GT500 because the intercooler is attached to the bottom of the blower. After unbolting the lower manifold from the heads and removing all but the front two blower-to-manifold bolts, Justin props up the blower snout to access the bolts on the intercooler fluid manifold.
Like the inlet side, the discharge...
Like the inlet side, the discharge side of the two superchargers tells a similar tale. The discharge V on the stock supercharger (right) is much smaller. Students of the sport may appreciate that the vents abreast of the stock blower's discharge port are there to tame blower noise.
Next, Bobby removes the stock...
Next, Bobby removes the stock induction hose, stock mass air meter, and CAI. You can remove the induction as one piece to speed up things.
With the intercooler fluid...
With the intercooler fluid manifold removed, Bobby extracted the remaining two blower bolts. Then Justin and Bobby could lift out the stock M112 supercharger and intercooler core. Now you must remove the intercooler core from the stock blower. These bolts are notorious for breaking. Sure enough, one of ours snapped off, but by using heat on the remaining bolts, Justin was able to remove them without a hitch.
Next off are the stock throttle...
Next off are the stock throttle body and inlet elbow. The TVS features its own inlet elbow, and it requires a lot more airflow than the stock throttle body will support. As such, these items weren't re-used.
The VMP TVS ($3,399, right)...
The VMP TVS ($3,399, right) packs considerably more boost potential and efficiency in a package that is approximately the same size as the factory supercharger.
Before installing the VMP...
Before installing the VMP TVS, be sure to swap the two locating dowels from the stock blower back to the lower manifold. These dowels ensure proper alignment of the supercharger.
With the intercooler installed,...
With the intercooler installed, the VMP drops right into the stock lower manifold as if it belongs there. It's handy to have a friend help you maneuver it into place.
Remember the intercooler manifold?...
Remember the intercooler manifold? Well, it mates with these two fittings in the intercooler core. Here Justin reinstalls the inlet and outlet fittings. Then he bolted the intercooler fluid manifold back on, lowered the supercharger into place, and bolted the blower and lower intake into place.
Obviously more boost requires...
Obviously more boost requires more fuel. To that end, Justin upgraded Jeff's car with eight Injector Dynamics' 98-lb/hr fuel injectors (PN ID1000; $899). According to Justin, these massive injectors were easy to tune up for power and driveability.