TPC Racing’s 993 GT2 EVO
TPC Racing’s 993 GT2 EVO
Mike Levitas on the Brute Force of “Orange Crush”
By: Brian Nixon Photos By: John Squire
Michael Levitas, a 2006 Rolex 24 at Daytona champion race car driver, and owner of the winning team TPC Racing, roots are firmly founded in his orange crush. No, not the soft drink, but a carbon-fiber clad 800-plus horsepower twin-turbocharged machine that marries key elements of a Porsche 964 and a 993 GT2 EVO.
This car has taken Levitas from Porsche Club of America club racing to campaigns in the old Rolex Grand-Am Super GT class and now back to club and vintage racing events. For Levitas, the car has been a learning tool — both on the track and in the shop — and a test mule. He’s poured his expertise and sweat equity into it and gained new knowledge in return. He’s had a lot of fun, too.
TPC 993 GT2 EVO “It’s a noble cause to chase a thoroughbred, but be forewarned if the orange car is in your run group. This car ran away from an angry pack of 962s at Rennsport Reunion II at Daytona.”
THAT COUPLED FEELING
In many circles, it’s known simply as “the orange car.” On circuits around the country — particularly those on the East Coast — it’s also known as the one other drivers try to beat. It’s a noble cause to chase a thoroughbred, but be forewarned if the orange car is in your run group. This car ran away from an angry pack of 962s at Rennsport Reunion II at Daytona.
Levitas describes the car as a 1990 Porsche GT2 EVO, but there’s more to it. It was purpose built for Grand-Am racing following homologation rules and mini-mum weight requirements.
Under the rules at the time, the mini-mum weight in the unrestricted category was 2,660 pounds (with an empty fuel tank but all other required fluids on board). The final “dry” weight of Levitas’ car was 2,666. That’s a result within 0.23 percent of the goal. And Levitas got there without added dead-weight ballast, an accomplishment that other spec-built car builders can’t always brag about.
The car’s carbon fiber body — were talking fenders, hood, doors, etc. — is in-deed a Porsche 993 EVO and was built from molds taken directly from 993 pan-els. The GT2 rear decklid and required Crawford rear wing are also carbon fiber.
The carbon fiber panels are hung on an earlier 964 chassis tub. Dzus fasteners securely mount the body components to the chassis while enabling easier and quicker access to internal and suspension components.
Levitas says he chose the 964 tub platform “because it was a very proven chassis.” As important, he adds, is that he could shift the rear engine/transaxle combination forward 1 inch.
The devil is in the details — and the 1-inch move forward was anything but dead simple — but the gain in balance and handling was well worth it. “It made a huge difference,” says Levitas. “The 993 guys couldn’t get the exit speed out of the corner.”
Inside the car, a custom cage fabricated by Levitas and his TPC team out of 4340 alloy steel adds serious rigidity to
the car while protecting the driver. This added rigidity is important in connecting the front and rear of a car and avoiding having a hinge in the middle.
As Levitas explains, “You want to have that coupled feeling.”
And lots of horsepower. The twin-turbocharged 1998 993 3.6 liter engine produces around 824 ponies on the TPC dynamometer (actually TPC racing has two dynos in its shop). By way of comparison, the turbocharged Penske Racing 917/10 driven by George Follmer that won the 1972 Can-Am series produced 850 horse-power. Elite company, you might say.
Much like the rest of the car, details abound when it comes to the engine’s set-up.
For one thing, the engine’s cooling fan (remember, this is a Porsche air-cooled flat six), is driven by twin belts connected to the rear crank pulley. Most air-cooled 911s have but one belt for this application. However, with the torque and RPM range this engine is capable of (the redline is at 8,000 RPMs under 1.1 bar of boost), a single belt would simply give up the ghost. In fact, at the extremes, belt deflection and stretch was a very real issue, as Levitas could see in dyno testing.
TPC 993 GT2 EVO “The 993 GT2 Evo’s twin-turbocharged, 3.6 liter engine produces around 824 ponies… The turbocharged Penske Racing 917/10 that won the 1972 Can-Am series produced 850 horsepower.”
Top: The NACA inspired intercooler is vital in making big power. The design’s flow dynamics limit the amount of resistance thus generating more boost. Bottom: The engine/transaxle are moved 1 inch within the wheelbase to improve weight distribution.
The solution was the twin-belt drive. Even so, Levitas hunted around for industrial belts that were up to the abuse of the engine’s crank spinning at only-on-a-racetrack crazy revolutions.
Another detail underneath is the header-collector design feeding the twin turbos and exhaust system. For this application, Levitas, whose background is in engineering with a degree from Embry-Riddle Aeronautical University (based, interestingly enough, in Daytona Beach, Fla.), borrowed a design for a Lycoming aircraft engine he found online in old National Advisory Committee for Aeronautics — NACA — research files from the 1930s. The NACA, was founded in 1915 as a federal agency for aeronautical research. In 1958, NACA became the National Aeronautics and Space Administration, or NASA.
What the old Lycoming research and design showed was that engineers even then were paying close attention to engine airflow dynamics, including exhaust header tube size, angles, lengths and curves. While their modeling techniques were crude compared to what can be accomplished today, their results were quite contemporary and applicable. What works, works.
TPC 993 GT2 EVO “Rocket science comes to mind when you ask Levitas about driving his orange GT2 Evo car. “All you feel is this horrible g load,” he says. “It feels like you’re in an experiment with a NASA rocket sled.”
Inside the engine’s case, a set of Carillo rods connect the TPC Racing-machined Mahle pistons to the balanced and polished crank. The engine’s compression ratio is 9 to 1 and a Motec engine management system provides the brains behind the brute force.
One particular innovation is the engines sealed combustion chamber designed by Levitas and his TPC Racing team. This involved sourcing a suitable material and machining a thin L-shaped ring that helps locate and seal the cylinder heads to the jugs. This sort of thing isn’t necessary on a street or even a moderate duty track car. However, in the performance regime Levitas’ car lives in, successfully sealing the combustion chamber means no loss of compression and power at the extreme.
The engine’s intercooler is another custom TPC Racing touch. Here again, Levitas paid close attention to airflow dynamics in smoothing things out to maximize the engine’s breathing. Ditto for the plumbing feeding the Garrett twin turbos, which feature lightweight integrated wastegates.
A custom TPC Racing flywheel connects the engine to the transaxle through a Tilton Engineering three-plate clutch. The GT2 gearbox features straight-cut gears. Driver gear changes are executed through a Fabcar Engineering shift assembly. The transmission is dry sumped and has an external cooler to keep things comfy under hard loads.
One footnote about the 1.1 bar of boost Levitas runs. While this might seem low, given the system’s efficiency, it packs plenty of punch without risking damage to costly engine internals.
GIVING AN INCH
Remember our mention of Levitas moving the engine/transaxle assembly for-ward 1 inch? While we don’t want to overstate things, getting there was nearly one of those for-want-of-a-nail situations.
Moving all that weight forward would reduce the pendulum effect at work in the turns. At the same time, Levitas didn’t want to change the car’s fore-aft wheel-base, since doing so would likely moot the gains made in the first place.
To accomplish both objectives, Levitas moved the engine and transaxle for-ward the required one inch while the drive shafts — no longer perpendicular to the gearbox and differential — would still connect to the rear wheels through pairs of inboard and outboard 935-type constant velocity joints.
TPC 993 GT2 EVO “With its tremendous acceleration, driving the car around a track becomes to a series of sprints. Accelerate hard, slow to a corner smoothly and blast out that’s repeated for 24 hours.”
Because of the somewhat unusual– and continuous–trailing operating agle, the drive shafts had to be longer than stock. And, with an engine wanting to put gobs of power to the pavement at the twitch of a right foot, drive shaft axle strength was also a concern.
Levitas sourced high-strength axles (think oﬀ-road carting here) that he had to cut down to fit — not a simple machining task given the hardness of the material. With patience and perspiration the job got done. Next up was machining the CV joint balls and races by a half-thousandth of an inch to improve their running because of the tricky operating angles.
Much thought went into the car’s other components systems, including the JRZ Suspension Engineering shocks, springs, struts and bushings, dual master cylinders that enable brake biasing adjustments from the cockpit, and multi-piston Brembo brake calipers for stopping power. There are lots more details, so take some time to study our spec sheet on the car.
One key takeaway from Levitas’ experience in building the car is that it takes effort and attention to detail. “The biggest lesson is if you’re determined to work
hard, you can make any project work,” he says. “Technology and practical applications have to blend. It’s got to meet the pavement somewhere along the line.”
WORDS OF WISDOM
When it comes to race car design, set up and driving Michael Levitas has two words of wisdom: “Exit speed, exit speed, exit speed.”
OK, that’s six words, but the treble emphasis underscores the importance of his advice. If you want to go fast around a circuit, it’s not so much about speed into a turn as it is about quickly departing a turn. You may have heard this bit of wisdom also described as “slow in, fast out.”
You want smooth corner entry and then the ability to get out quickly to the next turn. In fact, rocket science comes to mind when you ask Levitas about driving his orange 1990 GT2 EVO GTS car.
“All you feel is this horrible g load,” Levitas says. “It feels like you’re in an experiment with a NASA rocket sled.”
With its tremendous power and acceleration, driving the car around a track breaks down to a series of sprints. Accelerate hard, slow to corner smoothly and blast out. Repeat again and again, up to 24 hours.
“There’s something about pressing that gas pedal and freaking going,” Levitas says. “Any straightaway is a fun time. It’s an acceleration machine.”
So much fun that Levitas wonders why drag racers limit themselves to the quarter-mile. On a road course, drivers get to enjoy repeated drag races as they circuit the track.
On the track with his car, Levitas also gets to enjoy the feeling of the car pulling 1 g in fifth gear. “That’s brutal acceleration,” he says. “It gets your attention.”
And the attention of other drivers and onlookers as “the orange car” and its champion driver continue to dice and dance on various venues around the country.
IN LIVING COLOR
Levitas’ car is clad in a distinctive orange coating, and the interior cockpit and roll cage is yellow. It’s only natural to ponder what the exact orange color is. However, guess again if you suspect that the car is Porsche signal orange or a similar factory shade.
The car is actually industrial orange, as in, ahem, tractor-trailer fleet orange. Levitas found it one day while flipping through a book of industrial paint chips. The complimentary yellow for the car’s interior came from the same source book.
Put down your coffee now and take a deep breath.
Before getting wrapped around the axle about Porsche colors — how Stuttgart
and the boys at BASF Glasurit rightly understand best how a performance car ought to look –know that a race car lives a hard, dedicated life. Levitas wanted a finish that could stand up to abuse — the indignities of close encounters with Armco barriers and tire walls, the constant sand-blasting from track particles and debris, and the normal scrubbing and rubbing from other cars in the circuit scrum.
Race car designers and builders seek elegant, simple solutions to manifold challenges. In this case, Levitas’ orange paint, like so many elements of the car, works well. Add in the splashes of green — he got this idea from son Harry’s watching of Nickelodeon TV — and the car makes a distinctive and durable presentation.
OK, you can pick up that grande-sized coffee again.
Along with club racing and Grand-Am, the car has not missed a Rennsport Reunion, making on-track appearances at the first event at Watkins Glen International and the second at Daytona International Speedway.
It was at Rennsport Reunion II in the spring of 2004 that Levitas found himself on the grid with the clutch of 962s. The scene resulted in puzzlement from the 962 jockeys, who were clearly wondering, in Levitas’ words, “What’s that guy doing here?”
“Brian Redman (the famed driver and Rennsport Reunion organizer) knew
what he was doing,” Levitas recalls. The 962 drivers, on the other hand, did not know what was coming.
Adding to the confusion was the fact that Randy Pobst was introduced by the track announcer as the driver of the or-ange car, which resulted in much amusement from the Daytona paddock, where Pobst was watching events unfold.
The 962s got a surprise as Levitas sprinted oﬀ in the orange car and quickly cleared the field before dialing back the turbo boost a bit as the oil temp began to rise to an alarming level. “I was a half a lap ahead of the field,” he says. “By then I had proved my point. It’s just great fun.”
On the Daytona road course, Levitas’ car is running right around 199 mph as he passes the flagman and will top 200 enter-ing the next turn.
Levitas plans to continue to campaign the car in Historic Sportscar Racing events, club events and this fall’s Rennsport Reunion III at Daytona.
“The car kind of speaks for itself,” says Levitas. “It’s a balance of everything. It still presents to this day as a modern fighter.” AA
Brian Nixon is a veteran Washington, D.C.-based journalist. When not involved in writing projects, he can often be found in his garage, wrenching on his 1982 Porsche 911SC Targa and pondering the Teutonic mysticism of the five-gauge dash.
Right: Michael Levitas is not only a Porsche tuner, but a race champion with his 2006 Rolex 24 at Daytona GT Class victory in a TPC prepared 911 GT3.
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