When it comes to building lots of horsepower with power-adders, there are some people that are firmly devoted to superchargers with tons of torque and on-demand power. On the other side are the fans of turbos with their greater efficiency despite a little lag.
And then there are the freaks that have decided the only way to get the best of both worlds is to use both on the same engine. One of those freaks—and we mean that in the best way—is Hellion Power Systems, which has developed a kit that allows you to easily add twin superchargers to 2007 through 2009 supercharged Ford Mustangs.
Hellion’s twin turbo kit is the first produced in the United States for the Mustangs and works with either the factory supercharger, aftermarket superchargers or no supercharger at all with an optional sheetmetal intake. The idea of adding a turbo—or two turbos as is the case here—is called compound boost and it creates the best of both worlds. To get the same power you could just crank up the boost on a supercharger, but then you’re talking about a lot of horsepower wasted to spin the supercharger and you are also creating a lot of heat. You could also do the same thing with turbos, but making big power often means big turbos and that usually means the appearance of dreaded turbo lag.
One of the best features of the Hellion twin turbo kit is it is completely bolt on. It’s not only easy to install, it’s also easily removed. That’s why Scott Derrickson, the owner of Extreme Mustangs, decided to install the kit on his own car. Derrickson drives a 2009 Shelby Cobra. The car is not only valuable now, but it likely will only grow in value in the future. The Hellion kit doesn’t require chopping up the car, so if Derrickson ever wants to return the Shelby to its original stock form, all that’s required is to unbolt the components and reinstall the cats.
Another part of this kit that really caught our fancy is it is completely out of sight. Both turbos mount up approximately level with the frame rails. A quick glance under the hood reveals nothing, making this twin turbo kit a real sleeper. If you are the kind of guy, or girl, that prefers to talk softly but carry a big (horsepower) stick, this will definitely get your interest. After installation, Derrickson took the car to Pro-Dyno for tuning and they were able to safely crank out 741 horsepower and 743 lb/ft of torque from this combination at 17 pounds of total boost.
Download the Resource List for this build.
Download the printable Dyno Sheet for this build.
Photo 01—The subject for this install is the Extreme Mustangs house car, a 2009 Shelby Cobra. Definitely a nice car to begin with, and a monster when you add twin turbos to the already supercharged engine.
Photo 02—There is a lot more included in the kit than this, but the foundation of the system are the two Turbonetics 61mm turbos, two Turbosmart Ultragate waste gates, and the TurboXS Race bypass valve.
Photo 04—The first step is to remove the exhaust system from the catalytic converters on back. Having a lift like this does make life a lot easier, but you can perform this install in your driveway with your car on jack stands just as well.
Photo 05—After pulling the oxygen sensors, measure 10 inches back from the weld on the cats and cut them off. This space will be filled by the turbos. Now the rest of the exhaust can be reinstalled with the flanges supplied by Hellion.
Photo 07—You will need to remove the oil pressure sending unit, which is located next to the oil filter, and install the oil distribution block in its place. The lines from the distribution block will feed the turbos.
Photo 10—Loosen all the bolts around the turbo’s exhaust and compressor housings and install it on the car. Now clock the turbo so that the oil drain flange is on the bottom of the turbo and pointed toward the center of the car.
Photo 14—Greg Troutman hooks up the oil feed lines to the top of the turbos and the return lines to the bottom. It’s always a good idea to keep the lengths of the two return lines as close to equal as possible to make sure the pump pulls from both turbos equally.
Photo 15—Both turbos have been installed with the oil return lines routed toward the pump. Notice how they tuck up cleanly underneath the car so that they are safe from speed bumps and other road hazards.