1992 Pontiac Formula Firehawk, an SLP Hot Rod Available Straight From Dealers

From the June 1991 issue of Car and Driver.

In the beginning, hot-rodders lived by the Two Commandments: Thou shalt make it faster, and Thou shalt make it cheaper. Now there’s a third command­ment: Thou shalt make it legal.

You can still get away with perfor­mance tinkering if you do it by your lone­some, but modify an engine for money, or even worse, try to sell complete hopped-up cars, and more government agencies than you knew existed will pounce on you as if you were dealing crack.

Nonetheless, a trend in making more speed is to become a small-volume man­ufacturer, even though that requires enormous expenditures for testing and development. “Green speed,” as it were, is the way of the 1990s.

Enter the Formula Firehawk, available from your Pontiac dealer as the “Regular Production Option B4U.” It is emissions-legal, crash-tested, its parts are un­der warranty, and it’s faster than any­thing you can buy for its $51,989 price. And in many ways, it’s very much like driving a hot rod—wild and woolly.

The idea here was to build a car with ZR-1 performance for less than the Cor­vette’s $68,000 price. The ZR-1 perfor­mance is there. The lower price is there, too. But the tradeoff is refinement, or lack thereof. We’ll tell you about that later.

The Firehawk is the work of Street Le­gal Performance Inc., a four-year-old company in Toms River, New Jersey, cre­ated by former drag-racer Ed Hamburger. He learned the tricks of the horsepower trade in the 1970s and by selling speed parts to racers. Hamburger’s Oil Pans Inc., a company he started in ’79, lists as customers Dale Earnhardt, Darrell Wal­trip, and 26 other Winston Cup teams.

The Firehawk is Hamburger’s first complete car. It’s a Pontiac Firebird For­mula with a new drivetrain, the Firebird’s 1LE showroom-stock racing suspension, wider wheels and tires, plus a few other performance add-ons. SLP proposed selling the Firehawk through Pontiac dealers. Pontiac liked the idea. “It will help the performance image of the Fire­bird,” says Pontiac general manager John Middlebrook. The gates to GM’s mammoth Milford proving grounds were opened to SLP to test and develop prototypes.

SLP is planning to build 250 Fire­hawks, starting in June. The finished car won’t appear in Pontiac ads, however, since it’s a deal between SLP and Ponti­ac’s dealers, according to Middlebrook.

To order one (the only color is red), drop off a $5000 deposit at your Pontiac dealer. A 5.7-liter Chevy V-8 powers the Firehawk. It is built by General Motors Parts division to SLP’s specifications. These folks assemble the monster mo­tors we told you about in April—300-plus-horsepower Chevy V-8s you can buy and install yourself into classic cars built before the Feds got regulation-hap­py. The Firehawk’s engine consists of a stock block, a forged-steel crankshaft, special connecting rods, and lightweight cast pistons. The engine’s cylinder heads will be shipped to SLP’s headquarters in New Jersey, where they will be ported, and then shipped back to the assembly plant in Flint, Michigan. Completed en­gines will then be shipped to SLP, which will install them in Firebird Formula models. SLP warrants the powertrain, and Pontiac will cover the rest of the car.

“If you could take the best parts and build the ultimate Firebird engine, these would be the ones,” says Chuck Jenckes, SLP’s chief engineer.

For the port-injected engine, SLP de­signed a free-flowing intake system with two air cleaners—one occupies the space normally meant for the car’s battery, which goes in the trunk. The engine is emissions-legal in 49 states; SLP intends to certify Firehawk engines to California standards after production begins.

Engine power is fed through a Cor­vette six-speed transmission and clutch to an aluminum driveshaft (lighter than stock to aid power delivery, says Jenckes). The driveshaft turns a Dana 44 rear end with a one-inch-larger ring gear for durability and special beefed-up axles driving the rear wheels. Stiffer bushings in the rear control arms keep the axle from hopping during maximum acceleration.

We were impressed by the engine in our test Firehawk. It will rev to its 6000-rpm redline like a mad turbine, and it feels like it could rev a lot faster were it not for its 6100-rpm rev limiter.

An optional package for racers in­cludes the same front brakes you’ll find on a $400,000-plus Ferrari F40. This package is worth about $11,000 of the Firehawk’s price, and includes a roll bar, a lower front end, an aluminum hood, a five-point harness for the driver, and a Recaro seat. Our test car, a devel­opment mule, had everything but the roll bar.

“The racetrack is really where the car’s going to be at home. It’s kind of obnox­ious on the street,” says Jenckes. How true. It shook, and it felt unstable most of the way up to its 158-mph top speed. Some of its nervous character is a result of beatings: Our test car had more than 20,000 miles on it, at least half of which were tallied at GM’s test track, says Jenckes.

The car felt, shall we say, unrefined on the street. The steering was darty. The Firebird front suspension and steering has trouble, we believe, maintaining control of the Firehawk’s extra-wide 275/40-17 tires. A ZR-1’s front tires are the same size as all four Firehawk tires, but the Corvette doesn’t wander over bumps the way the Firehawk does. GM designed the Corvette to ride on fatter rubber; stock Firebirds ride on nothing larger than 245/50-16 tires.

“Its sophistication is not high,” says Pontiac’s Middlebrook, who drove a pro­totype Firehawk last summer, “but brute power is there.”

Adds Jenckes: “It’s a broadsword in­stead of a scalpel.”

We did our fair share of beating this Firehawk, too. Following our top-speed test on the track, we did repeated full-­throttle starts, at least a dozen in a half­-hour. On our final run, the engine felt just as strong as on our first tire-squealing start. Our best time to 60 mph was 4.6 seconds, and our best quarter-mile run took 13.2 seconds at 107 mph. That’s as quick as the las1 ZR-1 we tested, quicker than the Acura NSX, the Lotus Esprit Turbo SE, and the Ferrari 348ts we tested in September. But those cars won’t dislodge your fillings.

This performance comes from an en­gine that started instantly for us one sub­freezing morning. Cold or hot, the mo­tor’s idle is a lumpy but steady 850 rpm.

The optional brake rotors are massive, drilled thirteen-inch discs—as big as the wheels on a Honda Civic. Four-piston Brembo calipers grab these discs and haul down the Firehawk from 70 mph to a stop in 164 feet, only nine feet farther than a ZR-1, two feet shorter than a Porsche 911 Turbo. The brakes are tough to modulate—we promptly locked a wheel during our first hard stop. The flat-spotted tire, coupled to the stiff ride of the Firehawk, caused one of our test drivers to comment: “Its sensory level is a close second to riding in an industrial dryer.”

The Firehawk is a tough car to ride in. It is noisy and stiff. “Riding in it is the most fun I’ve had since I got thrown on my head by the mechanical bucking bronco at Gilly’s,” one test driver noted. Much of the noise in our test car came from its well-worn Firestone Firehawk tires grumbling on the pavement, and those sounds were transmitted directly to the driver to combine with prodigious amounts of wind noise and body creaks.

The six-speed shifted as smoothly as the same ZF unit does in the Corvette. The transmission retains the computer­-forced upshifting used on the Corvette, although it was disabled on this proto­type. That feature and the tall gearing (70 mph in sixth yields 1650 rpm) keeps fuel economy above the EPA’s gas-guz­zler limit. We rarely used sixth—or fifth. Fourth gear at 70 mph keeps the engine at 3300 rpm, ready to roar at a moment’s notice.

A half-dozen supercars can outrun the Firehawk. All ride better, but none are cheaper. To match the Firehawk’s 158-mph top speed for less than its $40,995 base price (minus the racing package op­tion), you could attempt to build this car in the privacy of your garage. It would still cost plenty, but you might avoid these astronomical pitfalls: the emissions testing and certifying process ($50,000 minimum); the backward-barrier crash to satisfy the Department of Transporta­tion requirement that the new rear axle hasn’t compromised the car’s structure or fuel-system integrity ($20,000 plus bodywork); the two 200-hour dynamom­eter tests for engine durability (about $10,000 each, plus, says SLP’s Jenckes, another $10,000 for fuel); and one drive­line durability test that includes driving the car over hills and bumps under full throttle ($25,000). A small-volume man­ufacturer like SLP (250 cars per year or less) is spared the EPA’s 50,000-mile emissions durability test, but not much else.

The Firehawk succeeds as a 1990s hot rod—it is fast, ferocious, and clean. Still, we’d think about giving up some of its speed for more refined handling and less ruckus on the street. A couple of cheaper cars come to our minds: Nissan’s 300ZX Turbo and Chevy’s Corvette L98. But they’re not hot rods in the viscerally raw, traditional sense. The Firehawk is.