THERE'S AN UNDENIABLE allure to a supercharger. The debate over whether to go normally aspirated or forced induction in building power is a worthy one, but the academic reasons often fall to the simple fact that a blower is cool.
The A&A Corvette supercharger...
The A&A Corvette supercharger kit for C6s includes a Vortech V-2 SQ compressor, an adjustable bypass valve, and A&A's unique bracket/pulley design, which offers excellent belt wrap (the amount of the blower pulley that is in contact with the drive belt) to all but eliminate the chance for slippage. Not seen in this photo is the large heat exchanger for the air-to-air charge cooling system.
Blowers look cool, and they certainly sound cool, and with the benefits of modern tuning-and the fact that modern Corvettes have never been better equipped to handle them-they're relatively efficient tools for making big horsepower in an otherwise stock vehicle.
The kit comes with a 3.8-inch...
The kit comes with a 3.8-inch supercharger drive pulley that enables about 10 pounds of boost. That's great for street-driven vehicles that will be tuned for pump gas. The company also offers smaller- and larger-diameter pulleys that alter the maximum boost; smaller pulleys increase boost, but sometimes at the cost of pump-gas driveability.
We've seen plenty of Roots-type blower systems on C5 and C6 Corvettes, most of them versions of MagnaCharger kits, but comparatively few centrifugal blowers. So when we had the opportunity to follow the installation of a Vortech-based, intercooled system from Oxnard, California's A&A Corvette, we loaded up our camera gear and camped out at Detroit-area tuning shop Stenod Performance for the wrench-turning session.
"We were impressed with the kit," says Stenod's Joe Borschke. "From our experience installing and tuning it, it seems like a good value for our customers."
To facilitate the task of...
To facilitate the task of "pinning the crankshaft," the steering rack must also be removed. A&A Corvette also recommends removing the factory power-steering cooler in order to make room for the supercharger kit's plumbing. See the main text for more information on the pinning process.
Although Vortech offers a specific, intercooled kit for the C6, A&A's system is priced approximately $1,800 lower. Differences between the two include things like fuel injectors and A&A's inclusion of a Kenne Bell Boost-A-Pump for the fuel system, but the biggest differentiator is tuning software. Vortech's C6 kit includes a plug-in programmer, while the A&A kit does not.
"We don't believe in a pre-programmed tune," says A&A's Steve Padfield. "Each project is unique, so we believe it's best to have a custom tune performed at the time of installation."
In order to mount the intercooler...
In order to mount the intercooler and its related plumbing, as well as other components of the supercharger kit, the Corvette's front fascia must be removed. It involves carefully pulling out a number of delicate plastic push pins, as well as the removal of the front wheels.
Of course, that presupposes a qualified tuner is available in a customer's area. But assuming one is, it's definitely the method that ensures optimal performance. In the case of our project, additional engine modifications necessitated a custom tune that would have rendered a pre-programmed calibration unusable anyway.
The test vehicle for this story was an '05 automatic with a mere 4,000 miles on the odometer. Like all '05 models, it features a 6.0L LS2 rated at 400 hp and 400 lb-ft of torque.
There are two major things...
There are two major things to note in this photo. First, at the 5 o'clock position on the crankshaft hub, the pin to lock together the crank and balancer/pulley is installed. Second, at the bottom right of the balancer/pulley, threaded into a drilled-and-tapped hole in the front of the oil pan, is the required oil-return port that links to the supercharger head unit.
As with any intercooled system for a late-model Corvette, the installation involved removing the front bumper cover to provide room for the heat exchanger and related plumbing. Generally speaking, the kit was well engineered and used first-class materials. Kevin Gluski, the installer at Stenod Performance, found some of the instructions in the downloadable assembly manual to be a bit vague, but the overall impression on the fit and finish was one of admirable quality.
That's not to say the project wasn't without its difficulties. Regardless of whose kit is used, stuffing an intercooled supercharger system into the tight confines of a Corvette's nose isn't easy. Care must be taken to ensure adequate clearance for a variety of hoses, tubes, electrical lines, and more. There are a few other details worth mentioning:
When drilling and tapping...
When drilling and tapping the oil pan, white lithium grease should be used on the end of the bit to hold shards released during the drilling process. Keeping this debris out of the oil pan is vitally important. Some installers even drill the initial hole in the pan prior to draining the oil, allowing material to flow out with the old oil.
Like all late-model, LS-engine vehicles, the precaution of "pinning" the crankshaft is necessary, because the balancer is press-fitted to the crank hub. Pinning the crank involves drilling a hole or two between the balancer and crank, and inserting a dowel-type pin to provide a simple lock between them. This prevents unwanted slippage that could occur under the greater load imposed by the supercharger.
Pinning the crankshaft requires the removal of the steering rack, which includes holding the steering wheel in place to ensure it aligns perfectly when the rack is re-installed. Otherwise, driveability will suffer, and the rack will likely need to be removed again to correct the problem. Reinstallation of the steering rack automatically means a trip to the alignment shop, too.