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.