Muscle Mustangs & Fast Fords
2005 Mustang GT 5.4L Twin-Turbo Kit - Clone Wars
It's Not A Real GT500, But With A 5.4L Swap, Home-Built Twin Turbos, 750 Rwhp, And 24 Mpg, Who Cares?
Boost isn't something that's sold by the gram in dark alleys of the inner city, but based on Mike Ivy's penchant for the stuff, that's exactly what you'd think. He's a serious addict, a psi junkie, a man that needs a 12-step program for hopeless boostoholics.
Mike's past and present force-fed projects include a pair of SVO Mustangs, a Whipple-charged '01 Lightning, a Vortech-powered '93 Cobra, a twin-turbo 337ci '93 Ranger, and two Terminator Cobras. The natural order of progression suggested that a boosted S197 was next on the hit list, and when Ford announced its plans for the '07 GT500 four years ago, it seemed like destiny was calling. However, patience is something that most addicts lack, and waiting a couple of years for the new Shelby to roll off the production line--then paying the inevitable markups that would follow--wasn't very appealing. His solution was to purchase an '05 GT instead, and take the process of manifold pressurization into his own hands.
Not surprisingly, Mike's new Mustang didn't stay naturally aspirated for long. Almost immediately after taking delivery of his project car, he slapped on a ProCharger. Shortly thereafter, the setup no longer felt adequate, and was replaced with an STS twin-turbo kit, at which time the factory slushbox also got booted in favor of a Tremec TR3650 five-speed. "I loved the way the car drove with the five-speed and STS turbo kit, but I started having trouble with a return oil line on one of the turbos," Mike recollects. "I had a pair of turbos that were custom built for my Lightnings just sitting in boxes, and the compressor maps looked like they'd work pretty well on the Mustang's 4.6L motor. One thing led to another, and I built some custom piping that mounted the turbos underneath the car, right next to the transmission. I thought I had the turbos shielded pretty well, and they did survive several thunderstorms, but one morning they sucked up some water during an extremely heavy downpour and it ruined everything."
For the next two months, Mike fervently debated between building up a big-bore 324ci mod motor or dropping in a 5.0L. His plans starting coming together when he stumbled upon an eBay auction for a low-mileage, three-valve 5.4L truck motor. "The engine was in great shape--for $1,700, I couldn't pass it up," he explains. "After swapping in a set of Manley rods, boost-friendly 8.2:1 forged pistons, a Modular Mustang Racing windage tray, and a modified 4.6 oil pan, it was ready to go. I did some minor porting on the heads myself by working the bowls and touching up the runners. The stock cams work very well with forced induction, but I installed a set of MMR 225/235-at-0.050 cams to add a little lope."
With a goal of 1,000 hp for the new setup, Mike spec'd out a new pair of Turbonetics 62mm huffers. Instead of moving around underhood components or tossing them in the trash to free up space, Mike wanted to retain all accessories and keep everything close to their stock location. Consequently, in lieu of custom headers, he installed port-matched exhaust manifolds off of an F-150, flipped them around, and fabbed up custom exhaust elbows that mount the turbos as far forward in the engine bay as possible. Exhaust exits through 3-inch downpipes that neck down to 2.5 inches at the H-pipe.
More custom tubing routes compressed air from the turbos into a front-mount intercooler before it makes its way into a custom MMR sheetmetal intake manifold. Tial wastegates regulate the boost, and an HKS blow-off valve protects against compressor surge. Fueling the beast is a GT500 dual-intank pump--augmented by a Kenne Bell booster--and RC Engineering 75-lb/hr injectors. Dual -8AN lines, one for each rail, provide some serious fuel volume.
Mike tuned the combo himself using SCT software, and the car currently puts down 750 rwhp at 15 psi on pump gas. Once he puts the finishing touches on the programming and cranks the boost up to 20-25 psi, Mike hopes to lay down 900 hp on race gas. To make sure all that power actually makes it back to the wheels, Mike swapped in a Tremec TR6060 six-speed, and fortified the rest of the driveline with a GT500 dual-disc clutch and a custom 4-inch aluminum driveshaft.
As the car neared completion, Mike tried to reinstall the headlights and realized the routing of the intercooler piping wouldn't work with the stock front clip. He took some measurements and concluded that GT500 body parts would yield some badly needed real estate under the hood. Always a fan of the Shelby's styling, he ordered a GT500 hood, headlights, bumpers, grille, and side skirts. "I'm not a big fan of cloning a car, but I knew my car could back up its looks with more than enough power," he says. "I avoided putting GT500 badges anywhere on the car, but I did feel it was worthy of having Cobra emblems on the fenders."
In the near future, Mike plans to put it all to the test by competing in the Texas Mile, where he hopes to top 200 mph. He admits that it will be tough since the S197 isn't the most aerodynamic of designs, but he's confident it will happen once he reaches his goal of 900 rwhp. So while the cloning debate can go on and on, it's tough to find any faults with a car that makes nearly twice as much power as a real GT500--regardless of how it's badged.