Shelby GT Procharger
The '07 Shelby GT special-edition Mustang was made available in response to an enormous demand for a retail version of the Shelby GT-H Mustang, which could only be had as a rental car from Hertz. Aside from the obvious visual cues, these cars were substantially modified in Shelby's Las Vegas facility before delivery to the customer.
A Ford Racing Handling Pack with specially tuned dampers, unique sway bars, and a front strut-tower brace began the chassis transformation. New coil springs dropped the overall ride height by 11/2 inches for a more aggressive stance and reduced body roll. High-performance P235/50ZR18 BFGoodrich g-Force T/A KDWS tires maximize the benefits of the chassis upgrades. Coupled with a 3.55 rear-axle assembly for extra off-the-line acceleration, the Shelby GT is an everyday driver that's tuned for command performances at the track.
As it came from the factory, the '07 Shelby GT was rated at 319 hp and 330 lb-ft of torque at the flywheel. The car's V-8 engine is modified with Ford Racing's Power Upgrade Package, which includes a 90mm cold-air intake and a new performance engine calibration system for improved response. The high-flow exhaust system with x-style-specific crossover offers better power delivery and a throaty exhaust note that makes this car unmistakably a Shelby.
The Shelby GT is a more dynamic, more engaging version of the Mustang GT, with sharp reflexes and a track-ready suspension, but for this car's owner, it still wasn't enough. That was when he got into discussions with Terry Johnson at Street Lethal Performance, in New Castle, Pennsylvania. Johnson runs a Mustang performance shop that caters to all power-adder approaches, and he's also known as a specialist in 5.4L engine conversions for the Mustang.
In this case, the best decision was to rely on the tried-and-true supercharging route. An ATI ProCharger HO Intercooled System (PN 1FP214-SCI) with a P-1SC-1 head unit and three-core intercooler was Johnson's product of choice.
When the owner dropped off this pearly white gem, the first order of business was to strap the car onto the shop's Dynojet Research dyno to establish some "before" numbers. That run showed the Shelby was putting out around 274 rwhp and 297 rwtq. Then, it was time to get to work. Let's join the guys at Street Lethal and see what's happening.
On the dyno, this Shelby GT...
On the dyno, this Shelby GT showed good power output, but now it's time to raise the bar-a lot.
The first item to come off...
The first item to come off is the front fascia. There are several plastic fasteners along the top, as well as screws inside the fenders. You must take out the inner wheelwell liners to get to these.
This makes access to the front...
This makes access to the front of the Mustang much easier and clears the area where the intercooler will go later.
Along the way, you'll have...
Along the way, you'll have to drain the cooling system, so it's best to do it now. Of course, you should also make sure that the battery has been disconnected.
Remove the existing cold-air...
Remove the existing cold-air intake, including air filter, intake tubing ,and MAF sensor.
Some preassembly work is helpful,...
Some preassembly work is helpful, including installing this idler pulley onto the aforementioned mounting bracket.
After removing the overflow...
After removing the overflow tank and power steering fluid reservoir, as well as the electrical connection, carefully take the electric fan out of the engine bay.
Here are the mounting brackets...
Here are the mounting brackets that you'll be dealing with-sturdy pieces, for sure.
Some of the Mustang's existing...
Some of the Mustang's existing pulleys have to be removed from their stock mounting points and installed on the ProCharger's mounting brackets.
With all pulleys transferred,...
With all pulleys transferred, the supercharger bracket can be fitted to the front of the engine.
All of the fasteners need...
All of the fasteners need to be tightened to the supplied torque specs. Don't guess on these-you'll find all of the specs in the instruction manual.
Here's the moment you've been...
Here's the moment you've been waiting for. The ProCharger P-1SC-1 unit is lowered into place on its bracketry. We can already hear the impeller spooling up.
Use a torque wrench to set...
Use a torque wrench to set the blower to the bracket fasteners.
At this point, the electric...
At this point, the electric fan can be reinstalled, along with the power-steering reservoir. There's a new radiator overflow tank to replace the original. Don't forget the electrical connector for the fan, either.
It's time to move on to the...
It's time to move on to the fuel-system upgrades. The fuel injectors are replaced with the higher-capacity versions supplied with the supercharger. With the electrical connectors disconnected, remove a couple of bolts securing the fuel rails. The injectors are easily pulled out for the swap to the kit's injectors.
Now, the serious plumbing...
Now, the serious plumbing begins. Getting the intercooler ready for mounting requires fitting the flex couplings and installing a set of brackets in front of the radiator.
With the intercooler securely...
With the intercooler securely mounted, it's time to finish the rest of the pipe work.
The last step is hooking it...
The last step is hooking it all up to the throttle body. It's best to leave the clamps loose until all the components are in place. That makes the inevitable adjustments a lot easier.
Here's the revised overflow...
Here's the revised overflow tank in place. You can see why the old one couldn't be reused.
With all that work completed,...
With all that work completed, it seems a shame to cover it all up again. Still, there are telling signs for those in the know.
After refilling the cooling...
After refilling the cooling system, we'll also install this Kenne Bell Boost-a-Pump product. This helps to ensure that the needed fuel pressure is available under all conditions.
Finally, the time has come...
Finally, the time has come to strap this Shelby back on the dyno and do some tuning for best performance.
When the rollers finally stopped,...
When the rollers finally stopped, the Shelby GT's new peak numbers had stopped at 440 rwhp and 397 rwtq, an improvement of 166 hp and 100 lb-ft of torque. That'll really set you into your seat when the go-pedal hits the carpet.
It's also necessary to go...
It's also necessary to go one range colder on the spark plugs.