Supercharger technology is ever changing, but the principals remain the same. A crank-driven belt drives an air pump, which in turn, pressurizes the intake manifold. When the valves open, more molecules of air enter the combustion chamber. After extra fuel is added, this super-charged air/fuel mixture ignites, making more power than a naturally aspirated engine could. Sounds like the perfect scenario, right?
Well, not exactly. There's no perfect power adder, and superchargers are no exception. First of all, an engine will experience parasitic loss, which is equal to the power it takes to physically spin the supercharger. Also, the supercharger itself creates heat, which is then transferred to the air moving through it—hot air is less dense air. There's no way around the parasitic loss, but over decades of development, supercharger manufacturers have developed ways to minimize heat transfer and cool the charge air.
The main way to do this is through intercooling, either through air-to-air or air-to-water intercoolers. Positive displacement superchargers typically use air-to-water intercoolers that are integrated into the intake manifold. Water or coolant flows through the intercooler, collecting heat from the charge air, and taking it to be cooled by air passing through the heat exchanger (which is mounted in front of the radiator). This works really well for street performance and short periods of extreme use, as in drag racing.
But when it comes to prolonged use under boost and high rpm, superchargered applications aren't the most efficient—especially when using a positive displacement supercharger. The reason for this is the inability for the intercooler and heat exchanger to dissipate heat efficiently enough to maintain power levels as seen on the chassis dyno for an extended period of time.
Jeff Lacina hustles through Turn 1 at Sebring International Raceway while testing VMP Supe
Enter VMP Superchargers. VMP jumped into the supercharger market a couple of years ago with its TVS kits for both Terminators and GT500s. Now, alongside the launch of its standard Street Performance Coyote TVS supercharger kit (PN 50L-TVS-STREET; $6,499), it's offering a track-oriented kit called the Ultimate Performance package (PN 50L-TVS-ULTIMATE; $6,999).
"What makes the VMP TVS kit different from other 2.3L blowers for the 5.0L are the huge dual-fan heat exchanger, JLT intake, high-quality Injector Dynamics fuel injectors, CNC blower inlet opening and matching high-flow elbow, and the modified nose drive that accommodates down to a 63mm pulley," says Justin Starkey of VMP. "You also get your choice of pulley when you order the kit," Starkey added. Pulley sizes range from 85mm to 63mm, which range in boost capabilities from 9 psi up to 18 psi.
So what is the secret to this kit working so well on track? "The cam timing you run will have an effect on boost, so you can run less aggressive timing and actually restrict the intake to make more boost," Starkey said. "Don't get too hung up on boost numbers. If you are concerned about engine longevity and safety, look at the whole combination: rwhp, ignition timing, and the octane you are running."
That tuning mentality combined with an exceptional intercooler system gives the VMP kit a serious edge on the competition. And since VMP has geared the Ultimate Performance supercharger kit toward open-track guys, it only made sense to contact a real track guy with a naturally aspirated Coyote to use as our test mule. So we called on Jeff Lacina, a self-proclaimed track guy and owner of Track Guys Performance Driving Events. Jeff is a master of the open track and has instructed many MM&FF staffers over the years.
The VMP Superchargers Ultimate Performance 2.3L TVS package for ’11-up Mustang GTs and Bos
Since he knew VMP was launching this kit, and having test-driven VMP's TVS-equipped Boss 302, he wanted to give it a try. In our Snap-on Tech Center at our office in Tampa, Florida, we strapped Lacina's GT to our in-house Dynojet chassis dyno. With merely an axle-back and K&N air filter, it pumped out an impressive 402 rwhp and 391 lb-ft of torque.
Starkey and technician Steven Cleveland made quick work of the installation while Lacina's car remained strapped to the dyno. It took about eight hours to complete the installation, including stopping for photo ops and lunch.
Once the install was complete and the VMP tune was loaded, we spun the rollers again, yielding 605 rwhp and 522 lb-ft of torque—on par with stock '13-14 Shelby GT500s. But the real results would be seen on track.
At Sebring International Raceway, with Lacina behind the wheel, we rode along and datalogged a 15- minute session. IATs rose, then hovered between 130-150 degrees, even during long WOT application like on the front and back stretches of SIR.
"Compared with other positiive-displacement supercharged 5.0 Coyotes I've driven, the VMP TVS system simply feels more eager—more willing to build boost and power," says Lacina, "but it's not rowdy or difficult to control out on the track. Some systems are so edgy that they can be a challenge to drive smoothly or the tune falls apart when you're outside of an optimal set of parameters. But not the VMP TVS system—the power delivery is very smooth and comes on in a predictible and manageble manner."