MORE POWER FOR MR. POWER
MAGNUSON BORROWS A HELLCAT TO TEST AND DEVELOP A NEW SUPERCHARGER KIT.
Magnuson borrows a Hellcat to test and develop a new supercharger kit.
True to his name, John Power possesses an unbreakable determination to extract maximum performance from every vehicle in his arsenal. Even the massively powerful Challenger Hellcat was inadequate for Power, so when his friends at Magnuson Superchargers were engineering their own forced induction setup for the SRT behemoth and asked to borrow his 2015 Hellcat for development work, he didn’t hesitate for an instant. Magnuson’s system, called Vengeance TVS 2650, is offered in two stages and both impart numerous benefits compared with the Hellcat’s OEM IHI Turbo America twin-screw unit. The Vengeance TVS 2650 Stage II setup, which is on Power’s Hellcat, delivers maximum performance while still retaining excellent driveability and reliability.
The benefits of the Magnuson system are the result of very clever engineering. By increasing the size of the charge air cooler inside the supercharger manifold
by a full 10 percent, the temperature of the intake air is measurably lowered. Further efficiency is gained inside the hybridroots supercharger, where high helix fourlobe rotors generate higher flow from a unit with significantly reduced displacement. The design also requires less horsepower to spin the supercharger, and its discharge temperatures are considerably lower. Put together, these advances allow a Magnuson-supercharged Hellcat engine to make up to 1,000 hp with the stock fuel system and over 1,400 hp with an upgraded fuel system and powertrain modifications.
“I have four Hemis and several other great cars, including a ’17 Nissan GT-R and an ’18 Mercedes-benz AMG GT R, so I really appreciate fast, well-built machinery,” explains Power. “The Hellcat is obviously a very fast car out of the box, but this Magnuson supercharger brings it to a whole new level, and I love it because it’s first quality and so beautifully engineered, with attention to even the smallest details.”
The TVS 2650 Stage II is a 100 percent complete, bolt-on system. Because Magnuson figured out how to get a lot more performance from a physically smaller blower, and put a lot of thought and effort into integrating it with the rest of the car, no hood modifications are required. The kit includes a high-flow intercooler system with huge 1-inch fittings to promote maximum flow, a 105mm throttle body inlet, anodized aluminum fuel rails, and interchangeable rear cog/belt pulleys that allow for up to 27 percent overdrive.
The basic system is compatible with the Hellcat’s stock electronic bypass valve and stock throttle body. It also works with the engine’s original 600cc/min fuel injectors and factory pulse-width-modulated, in-tank fuel pump, though ultimately all of these stock components will limit the blown engine’s potential to a maximum of about 1,000 hp.
“As it sits, without additional engine modifications, we’re getting 947 hp at the tires,” Power tells us. “That’s good enough for 6.38 seconds at 107 mph in the eighth-mile at Irwindale without pushing it too hard.” Magnuson nailed that time during development testing, and they were very conservative with the driving, because they were determined not to break anything. In fact, they were far more concerned about hurting something than
Power was. “I’ve been involved with highperformance cars for a long, long time and understand that when you get that kind of power out of a stock long-block, and put it through a mostly stock drivetrain, there’s an increased risk that you’re going to find the weakest link, but that didn’t bother me in the least,” he says while laughing. “I told them to push it harder, and if it breaks we’ll fix it. In the meantime I’ve got nine more cars to have fun with!”
To minimize the risk of drivetrain problems, Power turned to The Driveshaft Shop for a stronger-than-stock 4-inch aluminum driveshaft and their most durable axles. The 1,400hp axles are crafted with essentially unbreakable torsional 300M chromoly bars and modified Porsche-style 108mm CVS, featuring internal parts that have undergone the REM Isotropic finishing process. A sway bar modification kit and substitution of Wilwood rear calipers for the factory-installed Brembos are two more chassis modifications Power chose.
The new driveshaft’s twist gets to those impressive axles through a mostly stock differential with one important change. Automatic-equipped Challenger Hellcats are delivered with relatively modest 2.62:1 gears, which Power replaced with a readily available 3.09:1 ring-and-pinion set. The differential’s stock aluminum housing was developed specifically for the
Hellcat, and is beefed up in all the highly stressed areas. It also features a fourth mounting point compared with its predecessor. Internally, it uses a four-pinion, clutch-type limited-slip integrated with Dodge’s electronic stability control system tuned to maximize traction, and a 9.3-inch diameter ring gear, which is more than ½-inch larger than the Hotchkiss-type Dodge 8 ¾-inch ring that was a staple in the company’s legendary Hemi-powered automatic transmission cars from the past. With all of this, the stock differential should be able to handle the added power and torque the Magnuson supercharger delivers.
Looking ahead, Power’s next move is to install 1,000cc/min injectors, which by themselves will spike the engine’s output to over 1,000 hp at the tires. With upgraded fuel lines and pumps, a 105mm throttle body, Magnuson crank pulley pin kit, and Magnuson 27 percent overdrive cog pulley set, horsepower will top 1,400. To get beyond that number, Power will have to go deep inside the engine. The rule of thumb with a Hellcat is that 23 pounds of boost is safe with the factory internals, and 25 pounds or more is likely to break something, starting with the connecting rods.
“I enjoy driving all of my cars,” Power reflects, “so the only downside to going where I’m going with the engine is that I’ll need a net and parachute, because we’ll go over 150 mph. The faster it gets and the more safety equipment it requires, the harder it becomes to simply go out for leisurely cruises. But I can’t resist taking the Hellcat further and further.” With a name like Power, we wouldn’t expect anything less.