Breathless Performance Twin-Turbo C6 - Confidence Booster

Taken just before we went to print, this photo shows a vented hood and a roof-mounted air scoop that were recently installed on the car.

To be certain, a new C6 Corvette can provide quite a boost to its owner's psyche. Get behind the wheel, and your attitude and perceptions immediately shift toward an altogether higher standard. You become much more than a mere follower of the General Motors performance tradition. You become a leader.

For the ultimate confidence boost, though, you'll need to build your Corvette to its considerable performance limits. To accomplish this goal, Breathless Performance Products, of Dania, Florida, took its '05 shop car and out-fitted it with a stroked engine, low-compression heads, a bulletproof automatic tranny, and a massive infusion of twin-turbocharged power. The result is a streetable C6 that generates a rousing 950 horses and 850 lb-ft of torque.

"This is one of the very first turbocharged C6 cars," says BPP President Ernie Francis. "She was used as our test car for everything from the Vortex Rammer [cold-air intake] to headers, nitrous, and the final stage of the twin-turbo package."

The stock LS2 C6 came with 405 horsepower-more than enough to make most Vette owners happy. So why did Breathless take a perfectly good Z51 coupe and build it into an extreme-horsepower test car? "The answer is simple," Francis says. "We wanted to see if it could be done on a street C6, while keeping the reliability. This way, when a customer is interested in this power level, we can reassure him that it has been done and tested before."

First, Francis explored how he could modify the 364ci LS2 for enhanced output and reliability in a forced-induction application. For the rotating assembly, he chose a 4.00-inch Callies forged crank, 6.125-inch SLP/Manley forged H-beam rods, and 4.000-inch SLP/Manley forged pistons with a -28.5cc dish. This combo produces a displacement of 402 cubic inches and a boost-friendly compression ratio of 8.8:1.

Here's the Vette in an earlier incarnation. Visual modifications at this stage were limited to a pair of carbon-fiber front canards, a Z06-style nose scoop, various BPP badges, and a black-on-yellow checkerboard paint scheme.

The heart of the beast is a 402-cube LS2 stroker inhaling up to 20 psi from a pair of Garrett turbos. The combo huffs out approximately 950 horsepower and punts the C6 through the quarter-mile in the high 9s at more than 140 mph.

Our initial photo session took place at and around the Corvette Museum in Bowling Green, where we had an opportunity to sample the BPP C6 on the open road. God, is it fast.

Up top, the factory heads were CNC ported and fitted with 2.02/1.57-inch valves, dual springs, and titanium retainers. Modifications to the 4L65E transmission were minimal, consisting of a Yank torque converter with a 3,200-rpm stall speed. Incredibly, the driveshaft and rearend remain stock.

To prepare the Vette's fuel-delivery system for the rigors of turbo operation, Francis installed twin in-tank Walbro 255-lph pumps feeding humongous 82-lb/hr Motron injectors. With that done, he bolted on a pair of Garrett T04 GT35-T3 turbos mounted to BPP tubular exhaust manifolds and a Corsa 3-inch exhaust. A cockpit-mounted Breathless/Blitz SBC i-D III keeps tabs on boost, which vents through TiAL WG-35 wastegates. "At a touch of a button, we can go from 10 psi to a massive 20 psi," says Francis.

Body alterations include a BPP wide-fender kit, front winglets, and a nose scoop. Custom black-checkerboard graphics-a BPP trademark-were applied by Metro Signs. Inside, a BPP shift knob, a pillar-mounted gauge pod, a four-point race harness, and a six-point roll bar hint at the Corvette's prodigious output.

Interior mods are limited to a pair of pillar-mounted gauges, a BPP shift knob, a six-point rollbar, and a four-point racing harness for the driver. An electronic boost controller mounts unobtrusively below the factory sound system.

Since the car is primarily driven fast in a straight line, the factory Z51 suspension was adjudged more than adequate and left alone. BPP did, however, upgrade the rolling stock to a set of Hickock 18-inch wheels wrapped in strip-ready BFG Drag Radial rubber.

According to Francis, the car has more than earned its keep over the past few years. "Most of the products we manufacture get tested on this vehicle before they're approved for sale to the public. We don't just design a product and put it on the marketplace," he says.

Realizing that not everyone needs or even wants a 950-horse street Vette, Breathless Performance Products offers a full range of power mods covering virtually every level of output imaginable. "We have packages ranging from [Stage] 1 to 6, including our Turbo and Supercharger packages. It all depends on the customer's budget and how fast he would like to go," says Francis.

Track times for the BPP C6 prove that the company practices what it preaches. In quarter-mile testing, the wild, yellow Vette laid down a 9.92-second e.t. at 143 mph. If that's not confidence-boosting, we don't know what is.