Mason "Mase" Rowland of B&D...
Mason "Mase" Rowland of B&D Racing finagles a shorter Dayco drive belt (PN 50855) around the 3.25-inch, big-boost supercharger pulley on our Top Car Challenge Shelby GT500. Using a little muscle is necessary for installing the 85.5-inch belt, as well as removing an idler pulley that is used with the "stock" 4.0-inch wheel on Lysholm's twin-screw blower.
As we stated in the first article in our series on the 2010 Castrol Syntec Top Car Challenge ("Dangerous Drop Top," Sept '10, p. 76), we definitely learned a lot last year in the annual performance/endurance shootout that pits a Mustang flying 5.0's colors against five other rides (and their owners) representing Source Interlink Media's importcentric mags-Eurotuner, Super Street, Import Tuner, Modified Magazine and Honda Tuner. We're on a mission to improve on the fourth-place finish that Ron Cooper scored at the '09 Challenge with his supercharged '94 Cobra. To do this, Carlos Cortez and his '07 Shelby GT500 stepped up as our players for 2010.
We're putting Carlos' steed through a battery of buildups to ensure it will be ready to outperform the imports when the Challenge begins. The on-track tests are quarter-mile (e.t.), acceleration (0 to 60 mph), braking (80 to 0 mph), and-a crowd-favorite-the road-course showdown (lap time), and we decided to use a Shelby GT500 for its factory-borne power and improved handling over standard Mustang GTs. However, based on previous research with Mustangs, we know a good 'Stang can always be made better with the proper measures.
For Carlos' ride, a complete suspension makeover was performed using race-proven pieces from Eibach Springs, Maximum Motorsports, and Nitto Tire ("Maxed Out," Oct '10, p. 64). The new pieces replace previously installed hardware that brought the Shelby down some (lowered), but wasn't quite ready for the hard abuse our entry will endure during the contest.
Once our 'Stang's handling was dialed in, it was time for us to step up the Pony's performance program a bit. As we noted in the introductory report, our Top-Car contender is motivated by Ford's mighty Four-Valve, 5.4-liter engine and topped with Lysholm's enormous 3.3-liter Twin Screw supercharger.
With a VP Racing Fuels C-16 tune, the Shelby puts down 694.68 horses at the rear wheels, and 657.64 lb-ft of gut-turning torque, which we feel is plenty enough to place us among the top dogs at Top Car.
The Challenge is an event where contestants lay every ounce of their cars' performance on the line-especially horsepower-which is measured on the SuperFlow chassis dyno at K&N Performance in Riverside, California. While several performance criteria are evaluated in the Top Car Challenge, rear-wheel horsepower (unofficially) is the big deal in this contest.
Be it domestic or import, big steam ranks high when it comes to determining a street car's level of prowess. So with our mindset on big steam, we added a few cool hop-up goodies to Carlos' Shelby GT500.
The showstopper in our new-parts collection is a 3.25-inch supercharger pulley, which replaces the 4.0-inch Lysholm pulley. The reduced diameter increases the big blower's boost output by more than 5 psi, and we hope it will put our entry in front of the others when it's time to tally up its rear-wheel ponies on the dyno.
In the driveline department is the all-new twin-disc Dyad clutch system from Centerforce (PN 04114805). At 10.5 inches in diameter, the Dyad is a big step up from a Shelby's factory clutch package.
We understand the move was made in an effort to make pedal-effort somewhat minimal, but with the cars weighing 4,000-plus pounds and with the huge amount of torque GT500s can potentially create, the small clutch unit really doesn't stand much of a chance. The larger-diameter Centerforce has more surface area, friction coefficient, and a greater clamp-load capacity than the factory piece. These two qualities are keys to Dyad's overall effectiveness at moving as much of the Shelby's power through the drivetrain as possible.
It's show time, fellas! Take a close look at this report, and then look elsewhere in this issue to learn details of how our Shelby GT500 performed at the 2010 Castrol Syntec Top Car Challenge. And, if you haven't already done so, cast your peoples' choice vote for our entry on the website (www.syntectopcarchallenge.com).
Increased fuel volume is required...
Increased fuel volume is required when the Lysholm is turned up for max boost and power.
As such, our first task is...
As such, our first task is to replace the GT500's OEM fuel injectors (left), which are fine for the engine's 4.0-inch pulley/pump-gas tune, with Ford Racing Performance Parts 80-lb/hr squirters (right).
Once the belt is removed,...
Once the belt is removed, the pulley swap on our big twin-screw is super simple. A small dab of Loctite on each Allen-headed fastener helps ensure the pulley will stay put when it reaches full spin.