In its time, the supercharged, 5.4-liter Shelby GT500 was a game-changer. Carrying the torch ignited by the Terminator into the S197 era. Its brutish, supercharged grunt paired with the competent chassis resulted in an impressive performance car, but ultimately it was more of a straight-line machine.
The car is unreal. I could not believe how much difference the weight loss made in the car. — Jonathan Blevins, Chicane 23
It wasn’t until later on that Ford would shore up a suspension that had initially been geared toward an older customer. Eventually, Ford also transitioned it to an aluminum block to shave some of that weight off the front end. That said, making one handle is still a challenge, but it can be done, as proven by Chicane 23’s 2008 Shelby GT500 project, which competes in the Optima Ultimate Street Car competitions.
“It is my dad’s GT500,” Jonathan Blevins, of Chicane 23, explained. “He always wanted one and finally got it in December of 2007. The first track event for the car was the Shelby 85th. It has been tracked since then, and of the 16,000 miles on the car and over 10,000 are track miles.”
In the pursuit of more performance for this year’s competition, the Chicane 23 team sought to put it on a diet and add some power. The effort was successful, as the car lost 500 pounds and gained 157 horsepower, but not in the way you might expect. Instead of building up an aluminum-block 5.4- or 5.8-liter engine, Jonathan and company swapped in a VMP Performance TVS-supercharged Coyote 5.0-liter engine. That’s right, this is an SVT Shelby with the heart of a modern Mustang GT.
“Most are surprised. We cleaned up all of the wiring and anything that wasn’t necessary,” Jonathan said. “Most people haven’t seen a GT500 with a cleaned-up engine bay. It takes them a moment to notice the Coyote. Then they have a ton of questions. So far, everyone understands once I explain our reasons.”
In addition to the 500-pound weight savings, the 827 rear-wheel horsepower produced by an off-the-shelf, Ford Performance crate engine should be proof of concept enough to support this bang-for-the-buck swap.
“A built, 5.8-liter is getting really expensive. While the aluminum 5.8 would have been 100 pounds lighter than our 5.4-liter, the Coyote is more than 60 pounds lighter than a 5.8,” Jonathan explained. “The other advantage of the Coyote is a more advanced computer control system. This allows VMP to give us different power levels by gear.”
The reasoning is definitely sound, but the swap isn’t quite as daunting as you might imagine. Since the Coyote was originally designed to fit in the later S197 Mustangs, it can be made to feel right at home with just a few parts.
“The swap wasn’t too bad,” Jonathan said. “We used 2011+ headers and had to adapt them to the rest of the exhaust. The motor mounts and K-member worked just fine. The biggest difficulty was the steering shaft and power steering rack. This car still uses the hydraulic power steering. We ended up machining our own steering shaft and having to get custom steering rack bushing to rotate the rack back four degrees to get the shaft to clear the headers.”
While the decision to Coyote-swap the Shelby was pretty straightforward, the choice between natural aspiration and boost was a bit trickier. Pure road-racing machines are more tractable with an all-natural combo, but the siren’s song of TVS boost was just too much to resist.
2008 Shelby GT500 Mods
Block: Gen 2 Ford Performance 5.0 Aluminator aluminum block
Crankshaft: Forged steel
Pistons: Hypereutectic aluminum pistons w/ 11:1 compression ratio
Camshafts: Stock Gen 2 Coyote w/ billet cam Sprocket
Cylinder Heads: Aluminum cylinder heads, DOHC, four valves per cylinder, Variable intake and exhaust camshaft timing
Intake: VMP Performance intercooled lower
Power Adder: VMP Performance Gen3 2650 TVS supercharger w/ 85mm supercharger pulley and VMP twin 67mm throttle body
Fuel System: DeatschWerks twin 350-lph fuel pumps, DeatschWerks surge tank, DeatschWerks R2000 fuel-pressure regulator, VMP Performance fuel rails, and DeatschWerks 95-lb/hr fuel injectors
Exhaust: LTH Long Tube Headers1 7/8-inch long-tubes and full LTH system w/ multiple muffler options
Transmission: Built TR6060 w/ Ford Performance shifter and aluminum driveshaft
Rearend: 8.8-inch w/ WaveTrac differential
Engine Management: Ford Performance Control Pack w/ VMP Performance custom calibration
Ignition: Stock Gen 2 Coyote
K-member: Grigg’s Racing tubular
A-arms: Custom w/ Cortex aluminum spindles
Struts: Cortex/JRi double-adjustable
Brakes: 14-inch Brembo Race w/ Power Stop Calipers, G-Loc pads, and custom 3.5-inch ducts
Wheels: MMR 350, 19×11-inch w/ titanium lug nuts
Tires: Bridgestone RE71R, 305/30-R19
Control arms: Griggs Racing torque arm, Griggs Racing Watts link, and Griggs lower arms
Shocks: Cortex/JRi double-adjustable
Springs: Cortex/JRi double-adjustable
Brakes: GiroDisk rotors w/ Power Stop Calipers and G-Loc pads
Wheels: MMR 350, 19×11-inch w/ titanium lugnuts
Tires: Bridgestone RE71R, 305/30-R19
Better With Boost
In the end, moving from one boosted V8 to another was a wise choice. Not only is the engine lighter, but the new VMP TVS is more efficient, so it was a win all the way around.
“The old 5.4-liter still had a bit more torque, but other than that the 5.0-liter is far better,” Jonathan said. “It delivers more power with less heat, more RPM, less weight, and more control.”
The result of all those improvements is a Shelby that is far more capable of excelling in its intended environment. When paired with a sharpened suspension consisting of bits from Cortex and Griggs Racing, the TVS-boosted Coyote pushes this S197 to an even higher level of performance.
“The car is unreal,” Jonathan enthused. “I could not believe how much difference the weight loss made in the car. It corners so much better. We are still working on dialing in the suspension and we are seeing 1.4 to 1.5g on 200-treadwear street tires. Once you get to the straightaway, you better be ready. It pulls incredibly hard. We see .5g or higher all the way to 150 MPH. At the first event in New Orleans, we hit 166 MPH on the front straight. That is 17 MPH faster than the old setup.”
That is a huge improvement, but like any racer, Jonathan isn’t satisfied with maintaining the status quo on his unique GT500. A diet and further suspension upgrades are in the offing, but for now, he will enjoy competing in this special steed.
“For now we are really enjoying the Optima Ultimate Street Car events,” he added. “We won the NCM event and are currently leading in points in the our class. The car will be on display at SEMA in Optima Alley and compete in the Invitational after SEMA. We are looking at another round of upgrades over the winter. Most center around continuing to get weight out of the car.”