Story and Photos by Zach Mayne
Just about every car enthusiast who has built a project car is familiar with the problem of “mission creep,” when a project goes from a few basic goals to something far more extreme in its scope. The Porsche 930 Turbo pictured here is the perfect example of a build that began with a modest goal- in this case the relatively modest change to electronic fuel injection- and ended up with one ludicrously fast machine thanks to an 800-bhp engine.
Built into its current extreme state by Chris Carroll of Turbo Kraft in Mesa, Arizona, the 930 is owned by Tom McElligot, who also happens to be the creative mastermind behind some of Porsches best ads from the 1980s. Most Porsche buffs in their 30s and 40s and on up will probably remember the ad that pictured a Turbo from the back as it leaped a rise in the road, with the text underneath reading “One rode and you’ll understand why most rocket scientists are German.” That was just one of a series of successful ads he wrote for the German car manufacturer.
As the adman behind some of the company's more memorable advertising campaigns, it's no shocker that McElligot is a Porsche enthusiast of the highest order. He originally acquired the 930 pictured here in 1985 and which was the fulfillment of a longtime goal. He had owned a series of Porsches, from 356s to 928s, but the 930 Turbo was the ultimate Porsche for him. “Of all my cars, the 930 was the car I fell in love with and the one I’ve kept for 27 years,” he says. The Guards Red example was found in Germany, since at the time Porsche was not selling U.S.-legal versions of the legendary sportscar and federalized versions weren’t exactly common. “There were very few 930s on the market in those days, and people lucky enough to own one weren’t interested in letting them go,” he adds. The car had 2200 kilometers at the time and came without a sunroof, had only one exterior mirror and had manual seats. “It did have a full black leather interior and limited slip, a couple of things I really wanted,” says McElligot
Once the Porsche was federalized it was mainly used a weekend car. It also gained a few modifications over the years, including a bigger turbo, larger intercooler and headers. A close ratio gearbox was also installed to improve the car’s straight line performance, while the stock wheels were replaced with Fuchs-style HRE three-piece wheels that measure 17x8-inches up front and 17x0-inches at the rear. Front and rear Bilstein coilovers provide improved handling over the original torsion bar setup.
The 930 was fast and fun to drive, but at some point McElligot got the desire to convert to fuel deliver to EFI (Electronic Fuel Injection), which is how he ended up at Chris Carroll’s Turbo Kraft shop in Mesa, Arizona. Though the initial goal was merely upgrading the fuel injection, “in the end Chris and I decided to go for serious power, whatever that meant, with bigger displacement, more aggressive cams, a monster turbo, a gigantic intercooler and a long list of other power enhancements.” For Carroll, the project had four objectives. An honest and repeatable 600-bhp (which was exceeded), an EFI conversion, reliability and usability. “The engine was expected to have normal service intervals and to perform for years to come,” says Carroll. “Very low-RPM torque was not the objective but it could not have a peaky power band like an old-school racecar.” The build would also include performance parts that McElligot had collected over the years which included an Extrude-Honed Carrera intake manifold, oversize fuel rails, CMW billet heads and other parts.
The original 3.3-liter Turbo case was retained but was modified for more strength and better oil flow. One of the biggest changes though is the 996 GT3RS crankshaft that replaced the original and which allows the larger 3.5-liters when combined with larger pistons. “The GT3RS crankshaft has the same 76.4mm stroke as any 1989-98 3.6-liter engine but it has all the performance upgrades you would want as standard features,” says Carroll. “It’s lightweight, fully counterweighted, cross-drilled with chamfered oil holes, heavily nitrided and finely polished and balanced.” Custom billet rods from R&R were mated to the GTR3RS crank journals and a custom pulley allowed use of a standard fan belt. Mahle Motorsport 98-mm Turbo pistons and cylinders specially coated with a thermal barrier and low-friction coating were used. The CMW billet heads were extensively reworked and performance coated by Xtreme Cylinder Heads and then fitted with high-RPM valve springs and titanium retainers.
The heads work with custom, high-lift but medium duration cams. “The compression ratio is 8.0:1, similar to a 993 Turbo,” says Carroll. Billy Boat oil coolers in each of the front fenders work with the stock 930 oil pump, lines and oil tank. An Extrude Honed Carrera intake manifold is fed fresh air through a 4-inch diameter aluminum intake and a “huge” K&N cone filter. The exhaust consists of Billy Boat stainless steel, short-runner headers with integrated heat exchangers. 3-inch tubing connects the turbocharger to a custom Magnaflow stainless steel muffler.
For the forced induction, a Garret GT4094R ball-bearing turbo was used, along with Dual Turbosmart HKS wastegates and dual SSQV blow-off valves. A custom, full-width, computer designed intercooler was fabricated and uses a CNC-machined inlet tank and quick release couplings for the inlet and outlet. In an effort to extract as much power as possible, the Porsche’s fuel system was converted to run ethanol, which is cheaper than race fuel but is equivalent to 100-octane gas. The conversion required stronger Teflon fuel lines and special Aeromotive fuel filters. The fuel tank was modified to accept a larger ¾-inch fuel line, which leads into 1/2-inch lines after the first of two Porsche Motorsport 993 GT2 fuel pumps. “Because E85 has a lower energy content per gallon than gasoline, approximately 30-35% more fuel is required to make the same amount of power,” says Carroll. “This required larger diameter fuel lines, higher flowing fuel pumps and filters and very high flowing fuel injectors.”
The electronic fuel injection was designed entirely by Turbo Kraft. An AEM computer is used and offers three boost settings and monitors the engine’s oil pressure, fuel pressure and exhaust back pressure. The ignition system consists of Bosch coil packs that are triggered by M&W Pro16 CDI units.
In person, these old 930 Turbos look as ostentatious as ever, and this one is no exception. It has a super aggressive, almost cartoonish stance thanks to the flares, massive wheels and oversized rear whale tail. Inside is a ‘70’s-era Prototipo that frames the stock white on black gauges along with some Rennline components. The original seats have been replaced with deep Euro-spec GT3 buckets along with Schroth 5-point harnesses. In an effort to shed some pounds, lighter carpeting and flat RS-style door panels were installed. The back seats were scrapped to make way for a roll-bar.
At idle the Porsche is surprisingly quiet and civilized, with a trademark, air-cooled whir playing alongside a muted exhaust note. The clutch is on the heavy side with a pedal that feels like an on-off switch. A blip of the throttle immediately sends the tach needle swinging around a couple grand, but getting away from a stop is drama-free as long as you give it some throttle while releasing the clutch quickly and smoothly.
At lower RPMSs the engine is as smooth and tractable as a stock 930s and its apparent that this Turbo could be driven in stop and go traffic without a problem, though the heavy clutch would be a hindrance. As the tach needle swings to 3,000 and beyond though, the acceleration becomes intense, with the kind of violent, pin-you-back-in-the-seat speed that you can feel in your gut. The sound coming from the rear of the car transforms into a whistling, roaring monster. Lifting for upshift, the twin blow-off valves shhpitt loudly to relieve the excess boot pressure.
The 4-speed gearbox uses solid metal mounts, so the gearbox whines audibly at all times, adding to the sensory experience. Though the 930 is extremely quick in the most conservative boost setting- where it produces 569-hp at the rear wheels- there are two more levels that are accessed by two little switches on the dash. In these settings, the engine puts out 626-rwhp and 722-rwhp respectively. With that much power on tap, acceleration increases to a ludicrous level, reeling in the horizon in impressive fashion. Around corners, the 930 displays minimal body roll, the coilovers keeping the chassis planted and stable. For the uninitiated though, this is definitely a slow-in, fast-out car when it comes to the navigating the twisty bits. All up, this is one sweaty palms-inducing Turbo, something McElligot certainly agrees with. “Driving the car at speed is an exhilarating blast, not for the feint of heart,” he says. “I’m in my late ‘60s and this was sort of a last hurrah in a lifetime spent as a car guy."
Turbo Kraft • (480) 969-0911 • Broadway Mesa Commons, 1716 W Broadway Rd #123, Mesa, AZ 85202 • www.turbokraft.com