It's pretty hard to imagine Porsche's 996 being any less thrilling than it is, even when the car's in naturally aspirated form. The only way to make it better, really, is to make it faster, hence the Turbo. While factory Turbo models these days are rather hard to come by unless you've got a lot of money and a lot of patience, there is one company that's developed a forced induction alternative to the factory 911 TT. That company is Evolution Motorsports, and its boosted 996 Cabriolet relies on a Vortech blower, not turbos, to achieve its goals.
According to EVO president Todd Zuccone, the project came about as a way to offer customers a worthwhile and safe power upgrade, placing their Cabriolet's performance in 996 TT range while keeping the cost of the upgrades relatively low. EVO chose the 996 Cabriolet for the project because it makes an interesting alternative to the Turbo Cabriolet due to that model's limited production, but the kit is designed to accommodate convertibles and coupes alike. According to EVO, its SC Cabrio is less than half the cost and makes similar power. Reliability and driveability have been just as important in its buildup as improved performance. The car is, in fact, driven daily by Zuccone's wife, Jennifer.
"It's her favorite car, and she'll probably kill me if I try and sell it," Zuccone said.
Boosting naturally aspirated Porsches isn't anything new for EVO. A couple years ago the company built a twin-turbo 996 using a low-boost (6 psi) intercooled system. The car produced 360 hp at the rear wheels, but the cost involved in building the car was ridiculously high. Due to all the specially fabricated equipment-the elaborate plumbing, the exhaust manifolds, the oiling system and the turbos themselves-EVO claims the installed price at the time was well over $25,000, making the kit virtually unsaleable. The idea was scrapped and the intent to supercharge took its place.
According to Zuccone, the turbo package and the supercharger system do share some similarities. Both systems were designed to operate at a modest 6 psi of boost, and the company applied much of the knowledge gained in building the turbo system to building the supercharger kit, such as determining fuel management parameters and adapting an adequate lubrication system. Both systems were also fine-tuned by Garrett Lim of GIAC.
"His past experiences with tuning our twin-turbo 996 helped with tuning the 996 SC," Zuccone noted. "Garrett's ability to tune the driveability and full throttle with large injectors on the car is amazing. The car drives like stock at part throttle, and at wide-open it just has a seamless pull until redline."
Dyno results confirm the effectiveness of this approach: 354.3 hp at 6800 rpm and 271 lb-ft of torque at 5500 rpm.
VF Engineering (Anaheim, Calif.) provided much of the associated hardware, as well as helping plan and design the system in its critical early stages. The system is built around Vortech's V2 centrifugal supercharger, chosen for its adequate size and efficiency range for the 3.4- and 3.6-liter 996 engines. From the beginning intercooling was also a must, and the kit includes an OEM Porsche front center radiator, a Motorsports option that fits in the nose of the 996 without any modifications. The system is installed using OEM mounting hardware, brackets and air ducts, all included in the supercharger package. The intercooler system is a liquid-to-air unit that's fed by a sealed water cooling system that incorporates the aforementioned motorsport radiator and a quiet, high-flow Bosch water pump.
The blower itself is mounted in the engine bay by a CNC-machined billet aluminum mount; according to EVO, this too requires no modifications to install. Stainless-steel studs and mounting hardware are included to attach the blower and bracket. Additionally, mounting the supercharger requires no additional belt tensioner but runs a larger serpentine belt, also included in the package. All fresh-air feed pipes and charge air pipes are roto-molded plastic plumbing designed for heat resistance and adequate clearance inside the cramped 996 engine bay.
Of course, there are other niceties present on this car, most of which can be ordered directly through Evolution Motorsports. Drivetrain upgrades include an EVO/Sachs sport clutch and billet flywheel, as well as a B&M short shifter equipped with an EVO ShiftLink. A Fabspeed sport exhaust has also been included, as well as H&R lowering springs. The sparingly tasteful body mods, encompassing the TechArt Spoiler 1 and side skirts, were provided by CEC. The wheels are 19-in. RH MKs wrapped in Continental Sport Contact 2 tires. For locating this particular Cabriolet, EVO also extends thanks to the staff at Scottsdale Porsche.
EVO is currently prepared to sell, install and distribute the SC supercharger system worldwide through its network of authorized dealers. The Evolution Motorsports SC supercharger for Porsche's 996 carries an MSRP of $9,995. Unless you're on a list and prepared to drop an arm and a leg for a new 996 Turbo, it may be the most promising and attainable form of 996 forced induction.