2015 Callaway Chevrolet Corvette SC627 First Test

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Reeves Callaway is no stranger to high-performance vehicles. The professional racer turned engineer developed a twin-turbo kit for the C4 Chevrolet Corvette in the 1980s, and he's been building high-horsepower Corvettes ever since. His company's latest creation is the 627-hp Callaway Corvette SC627, and we took it to the track to see how well it would perform.

Based on the C7 Chevrolet Corvette Stingray, the Callaway Corvette SC627 makes 627 hp at 6,400 rpm and 610 lb-ft of torque at 4,400 rpm — increases of 167-172 hp and 145-150 lb-ft of torque over the stock Corvette Stingray/Z51. The centerpiece of the Callaway Corvette SC627 is a new Callaway-designed supercharger based around the Eaton TVS2300 rotor pack. The supercharger housing features an integrated intake manifold with a tuned runner and cross-section and a new triple-element liquid-to-air intercooler. Callaway claims that with the supercharger and intercooler system, inlet air intake temperatures increased less than 10 degrees after repeated dyno runs compared to other setups that saw increases of 35 degrees or more.

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GM used the Eaton TVS2300 rotor pack on the 638-hp, 604 lb-ft C6 Chevrolet Corvette ZR1. Where the C6 ZR1 featured a clear polycarbonate window to show off the supercharger, Callaway cut a hole in the stock hood to clear the tall supercharger housing, exposing it to cooling ambient air. The new 650-hp, 650 lb-ft 2015 Chevrolet Corvette Z06 uses a smaller Eaton TVS1740 rotating assembly that fits under the hood.

Other standard Callaway Corvette SC627 bits include a modified hood with trim ring, high-flow intake system, Callaway doorsill panels, exterior and interior badging, an under-hood plaque with VIN, Callaway key fob, and a three-year/36,000-mile limited warranty. Callaway's five-year/100,000-miles limited powertrain service contract is available as a $2,900 option. The Callaway Corvette SC627, which can be specified with any trim level, body style, or transmission, adds $17,995 to the price of a Corvette Stingray. A base 2015 Corvette Stingray 1LT with the Callaway SC627 treatment can be had for $73,990, and a base 2015 Corvette Z06 starts at $79,995.

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Callaway claims the SC627 can reach 60 mph in 3.4 seconds and finish the quarter mile in 11.0 seconds at 126 mph. At the dragstrip, the Callaway Corvette SC627 sprinted to 60 mph in 3.6 seconds and to the end of the quarter mile in 11.7 seconds at 123.7 mph. Braking from 60 mph took just 98 feet. The SC627 pulled 1.06g average around the skidpad and lapped the figure eight in 23.2 seconds at 0.96g average. The car had the stock Chevrolet Corvette Stingray Z51 suspension, not the available Magnetic Selective Ride Control adjustable suspension.

We tested two 2014 Chevrolet Corvette Stingray Z51 models with a seven-speed manual transmission. Those models accelerated to 60 mph in 3.7 and 3.8 seconds and finished the quarter mile in 12.0 seconds at 118.4 mph and 12.1 seconds at 117.7 mph, respectively. Both cars stopped from 60 mph in 95 feet. Around the skidpad, they pulled 1.06g average and 1.02g average, respectively. Those cars lapped the figure eight in 23.8 seconds at 0.85g average and 23.7 seconds at 0.83g average, respectively.

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Although the Callaway Corvette SC627 handily beats the stock Corvette Stingray Z51 in acceleration and handling, the new Corvette Z06 with the Z07 package is still the top dog. We've tested two 2015 Corvette Z06 cars with the Z07 package and a seven-speed manual transmission. Acceleration to 60 mph took 3.2 and 3.3 seconds, and the cars finished the quarter mile in 11.3 seconds at 126.2 mph and 11.4 seconds at 124.4 mph, respectively. Thanks to their carbon ceramic brakes, both Z06/Z07 models stopped from 60 mph in 91 feet. The high-performance Corvettes pulled 1.16g average and 1.17g average around the skidpad and lapped the figure eight in 22.5 seconds at 0.98g average and 22.3 seconds at 1.06g average, respectively.

Motor Trend hot shoe Randy Pobst lapped the Callaway Corvette SC627 around the track at Big Willow in 1:28.61. Although we haven't lapped the Stingray around Big Willow, Pobst lapped the Z06/Z07 at Big Willow on the same day. After Pobst made his best lap time, I got to ride shotgun with the professional racer in the SC627 around Big Willow. Where I managed to hit 142 mph on the long straight in the 640-hp 2014 SRT Viper TA, Pobst hit 146 mph in the less powerful SC627 (also with much less tire) with me in the passenger seat. During the ride, Pobst noted the Callaway Corvette SC627 is softer sprung than the Z06/Z07, which makes it more predictable. He also noted how well the SC627 puts the power to the ground coming off the corners. He said the Stingray Z51's stock brakes never showed signs of fade on the track.

On the street, the Callaway Corvette SC627 is as docile as a stock Corvette Stingray. The upgraded exhaust, which uses a single unitized acoustic chamber in place of the stock exhaust's dual mufflers, gives the SC627 the ability to make powerful sounds at wide-open throttle that don't resonate inside the cabin at cruise. Mashing the gas pedal in first and second gears causes the traction control light to flash and can produce wheel hop as the rear tires fight for traction. Despite our tester's low-key dark paint and dark-finished wheels, the SC627 got lots of attention from other motorists. Maybe it was the top of the blower housing sticking through the hood, the large CALLAWAY emblem across the rear fascia, or the large Double-D exhaust tips.

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Pricing for the Callaway Corvette SC627 depends on lots of variables, including, of course, the exact specification of the vehicle on which it's based. Our tester is based on the $62,205 (including $995 destination) 2014 Chevrolet Corvette Stingray 2LT Z51 with seven-speed manual transmission. (Customer cars will be based on the 2015 Corvette Stingray.) Before Callaway got its hands on the test car, factory options included $1,995 chrome wheels, $1,195 multi-mode exhaust, $995 transparent removable roof panel, $795 Chevrolet MyLink with navigation, and $100 battery protection package. With a factory-equipped cost of $67,285 and the base $17,995 Callaway bits, our Callaway Corvette SC627 tester had a base price of $85,280.

Optional Callaway equipment on our car included $2,890 Callaway Sport Exhaust system with Double-D exhaust tips, $3,890 Callaway nine-spoke forged alloy wheels with a black chrome finish, and the $530 Callaway short-throw shifter. Although the optional Callaway wheels are half an inch wider than the factory Z51 wheels (19.0 x 9.0 inches front, 20.0 x 10.5 inches rear versus 19.0 x 8.5 inches front, 20.0 x 10.0 inches rear), they are wrapped in the same Michelin Pilot Super Sport ZP run-flat tires (in the same 245/35ZR19 front, 285/30ZR20 rear) that come with the Z51 package. Overall, the as-tested price came to $92,590.

Pete Callaway notes that a customer choosing to upgrade to the Callaway wheels and exhaust would forgo the GM chrome wheels and multi-mode exhaust. That would lower the price of our tester to $89,400. Because Callaway Corvette SC627 customers will be starting with the 2015 Chevrolet Corvette Stingray, pricing will vary; a 2015 Callaway Corvette SC627 equipped like our tester would be priced at $93,350. Callaway is also working on other pieces, including carbon-fiber interior and body pieces and upgraded suspension and brakes.

The Callaway Corvette SC627 isn't trying to compete directly with Chevrolet Corvette Z06; rather, Callaway has built a fast street car for customers who want more than a standard Corvette Stingray. Customers who don't intend to do much track driving but could if they wanted. The SC627 offers a respectable power upgrade with subtle cosmetic touches that enhance rather than distract from the stock car's looks. Those paying close attention to the details will notice the supercharger housing ribs on the back of the new Stingray fender emblems.