827RWHP Coyote-Swap Shelby GT500 Is A Road-Course Rocket

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.

Sound Reasoning

“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.

Inside, Jonathan’s GT500 walks the line between street and racetrack. On the racing side, it is upgraded with an Aim MXG digital dash, Sparco Qrf-R seats, a Sparco steering wheel, and a custom rear-seat delete. The more esoteric improvements include a hydro-dipped dash, a custom shift knob, and custom leather on door panels, shift boot, and armrest. Another highlight is the custom iPad mount in the center console. This tablet acts as a source for a full custom audio system.

“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.

In the trunk is the real audio horsepower. Kicker digital amps feed an 8-inch subwoofer in a custom trunk box and speakers in the cabin. An Optima YellowTop battery ensures there is plenty of power to keep the tunes flowing and the Coyote howling.

Straightforward Swap

“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.

“We really thought about going naturally aspirated. When you consider that two of the three competitive driving segments of Optima are in a parking lot at speeds under 80 miles per hour, naturally aspirated is probably the way to go. The problem is this is the search for the Ultimate Street Car and I believe that the ultimate Mustang has a blower,” Jonathan explained. “I’ve driven several of VMP’s cars and had one of their TVS units for several years on our 5.4-liter. They provide the best drivability and durability for what we do. Most other superchargers bring on power abruptly and are hard to modulate the power coming out of corners. VMP works very hard on drivability and keeping the car driving like stock, only with a ton more power. When I heard about the new Gen3 2650 TVS and the ability to make more power with less boost and thus less heat, I was sold.”

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.”

Up front a Griggs Racing K-member and adjustable sway bar work with custom control arms, Cortex aluminum spindles and Cortex/JRi double-adjustable dampers to deliver maximum grip. Out back a Griggs Watts link and torque arm team to plant the Coyote power via a Griggs adjustable sway bar and lower control arms. The rear axle is cambered by Cortex to deliver -1.5 degrees.

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.

Unreal Engine

“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.”

Slowing an 827RWHP Shelby is no small chore, but 14-inch Brembo Race Front Brakes with floating, two-piece rotors do most of the work, while Power Stop rear calipers with GiroDisk rear rotors chip in. All the calipers are shod with G-Loc brake pads.

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.”