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The Weapon · 03-11-2010, 05:29 PM

2010 Hennessey HPE700 Camaro - Article - Road and Track

Quote:

You can order a 725-bhp Hennessey HPE700 LS9 Camaro in any color you like, but this very first example in stealthy Cyber Gray Metallic—with blue “hockey stick” graphics in an ode to the Corvette ZR1’s Blue Devil theme—seems appropriate. Makes me think of dark matter and dark energy in the universe, theoretical forces that can’t be directly observed, yet seem to toy with visible celestial objects with unimaginable energy. And supermassive black holes—you can’t see ’em (at least inside the event horizon, where even photons of light can’t escape their gravitational pull) yet they’re the engines of quasars, whose epic release of light and energy is the most impressive display of cosmic horsepower since the Big Bang...
The car world’s version of dark energy is before you, and easygoing Texan John Hennessey is the rocket scientist responsible.

John’s dazzled us before with outrageous twin-turbo Venom Vipers, one of which went 210.2 mph in our Standing Mile Shootout (September 2005). But now he’s stuffing the 6.2-liter LS9 V-8 from the ZR1 into the Camaro, trading exhaust-driven compressors for the 4-lobed helixes of Eaton’s TVS 2300 Roots-type supercharger.

Now the LS9 is the most powerful engine ever fitted to a GM production car—638 bhp in stock tune—but naturally, that didn’t stop Hennessey from extracting more power. A smaller pulley on the blower’s snout raises peak boost from 11.0 psi to 14.5, and the air-to-water heat exchangers within the central plenum are reworked for better flow. A carbon-fiber 4-in. cold-air induction system capped with a conical K&N filter lowers intake restriction, and 17/8-in. stainless long-tube headers expedite outflow of gases to a 3-in. X-pipe center section, high-flow cats and, curiously, a factory rear section that includes standard-issue mufflers. “The neat thing about superchargers,” says Hennessey, “is they’re not real sensitive to exhaust restriction…the blower will just force the air through the motor and out the exhaust. So don’t put a banana in the tailpipe of this thing; it’d launch it into outer space!” Well, with 725 bhp and 741 lb.-ft. of torque, a low earth orbit maybe.

Dimensionally, the LS9 isn’t far off the Camaro’s LS3 V-8, so it drops in without having to Slap-Chop the firewall or crossmember. But there’s far more to the conversion than meets the eye. “Where it gets complicated,” says Hennessey, “putting the LS9 in a car never designed to accept it, is in the electronics. In the modern CAN-bus system, the airbags talk to the radio, the radio talks to the engine, the fuel pump, and so on. All the computers are interrelated in this car. So we’ve probably spent the most time modifying the wiring harness and getting everything to work.” And the fuel system has undergone a thorough reworking, with larger injectors, a new fuel rail and higher capacity pump, as the Camaro’s system operates about 40 psi lower than what this thirstier-than-stock LS9 requires.

The end product is a beast that spits throaty, machine-gun bursts of sonic energy when revved, yet gurgles and burbles contentedly at idle and light throttle openings. And that’s before you even engage 1st with the stout, short-throw shifter (connected to the Camaro’s Tremec TR-6060 6-speed manual, bolted to the LS9’s block with an adapter plate) and attempt to transfer that tectonic torque to the fat Michelin Pilot Sport rear tires. It works best gently rolling into the throttle with minimal wheelspin. And then you’re pinned to the seat like an F-22 pilot in centrifuge training as 6.2 liters of force-fed fury erupts. Bang off a quick 1-2 shift and the expected tire chirp/slew event doesn’t happen; but the revs rise ominously and the rocket-sled ride resumes after a slight, sickening pause. Yep, it’s clutch slip, a scourge that repeats itself on each upshift through the quarter mile, but the HPE700 has still ripped through the lights in 12 seconds flat, with a trap speed of 125.4 mph and a shock wave that echoes off El Toro’s abandoned hangars.