Ford Motor Company unveiled a one-of-a-kind Ford Mustang twin-turbo powered Cobra Jet at the recent 2012 Specialty Equipment Market Association (SEMA) Show in Las Vegas, Nevada. For the first time ever Ford Racing has equipped its factory-built turn-key drag racer with a turbocharged engine, adopting the same technology found on road-going EcoBoost engines.
The original Cobra Jet Mustangs, which debuted back in 1968, were equipped with 7.0-liter V8 engines featuring massive four-barrel carburetors. These cars, which were built with racing in mind, were an instant hit at local drag strips across the country. “Racing pre-dates Ford Motor Company. Henry Ford himself raced the 999 and won in 1901 to generate interest for the new company,” said Jamie Allison, director of Ford Racing Technologies. “We haven’t stopped since. “We’ve competed in almost every category of auto racing, from deserts to road courses to ovals and drag strips over the past 111 years, often with cars and trucks based on our production models, including the Mustang,” Allison added.
In 2008, Ford introduced a modern day version of the classic Cobra Jet Mustang. “Ever since we relaunched the Cobra Jet in 2008, we’ve continuously evolved the engine to be more optimized for drag racing and produce more power for its NHRA class.”
“When a new generation of Cobra Jets arrived four decades later, they immediately began winning with a modern, fuel-injected 5.4-liter V8 topped with a belt-driven supercharger,” recalls Jesse Kershaw, Ford drag racing competition manager. “Over the past four years, the Cobra Jet has gone on to become both a fan and competitor favorite, the most successful late-model vehicle in drag racing.”
In 2011, Ford began equipping their modern day Cobra Jet Mustangs with the all-new 5.0-liter V8 found in the GT Mustang. The cars were offered both with and without a supercharger. “Despite its smaller displacement, the improved breathing of the 5.0-liter with its twin independent variable camshaft timing and Boss 302 cylinder heads provided comparable performance while showcasing the high technology available in street Mustangs today,” said Rob Deneweth, Cobra Jet powertrain development engineer.
Ford explains, while superchargers provide instant on-demand power, they can also sap a lot of power especially at high boost levels. The 2.9-liter blower used on the 2013 Cobra Jet uses as much as 100hp to drive the supercharger. That’s power no longer available for acceleration. Enter the twin-turbo concept Mustang.
“Ford has embraced turbocharging technology and a lot of our production engineers are working with the technology on a daily basis, so we have a lot of knowledge,” added Deneweth. “So we decided to apply that knowledge to the Mustang Cobra Jet to showcase what our engineers and suppliers know how to do.”
One drawback of turbocharging is lag. Ford Racing engineers worked diligently to find a way around this. “To overcome the biggest perceived drawback of turbocharging – the lag – we’ve selected the smallest possible turbos that will give us the airflow we need,” said Dave Born, Cobra Jet Team Engineer. “We’ve also got some other enhancements to help improve the responsiveness; we have very low inertia and very low internal friction.”
In order to qualify for NHRA Racing, parts like turbochargers must be derived from production components. As such, Ford worked with Borg-Warner to provide smaller, more efficient turbochargers based on the units used in the Focus ST for the Cobra Jet concept. Ford says that the turbine wheels are made from titanium aluminide that reduces the rotational inertia by 50 percent. Along with a shaft riding on low-friction ball bearings, the compressors can spin up to 150,000 rpm almost instantly.
In addition, the company reports that the same integrated, electronically controlled wastegates used on production EcoBoost engines enable the turbos to keep spinning and generating the boost pressure needed for low elapsed times and high trap speeds at the strip.
“We’re already using ball bearings in the turbocharger of the 6.7-liter Power Stroke® diesel V8 in Super Duty trucks,” adds Born. “We’re also evaluating materials like the titanium aluminide for the turbine, and it could find its way into future production programs as the costs come down.”
Ford is continuing to develop both the performance and durability of the twin-turbo Cobra Jet.
“For every Cobra Jet model we release, every powertrain goes through hundreds of hours of dyno testing and a minimum of 50 runs on the drag strip before we’ll sign off on the durability and capability of that engine and car,” adds Kershaw. “Like Ford vehicles for the street, we want to provide our racing customers with cars that are best-in-class, affordable and reliable.”
Source: Ford Racing