If you watch automotive television, you no doubt saw this Shelby GT350R receive a Hellion turbo system and put down 723 horsepower and 654 lb-ft of torque on just 9 pounds of boost. It was a great start, but car owner Jim Guthrie wanted to turn up the boost and make over four-digit horsepower. To do so meant upgrading the engine to handle more boost.
“We knew that the GT350 platform would be very similar to our GT system, so the answer was not if, but when we would make the adaptation,” John Urist of Hellion Power Systems explained. “We already have had amazing results with our record setting GT kit, so we knew we could push the Voodoo engine.”
Suited for Voodoo
Based on those initial results, the kit definitely works well on the Shelby GT350. Obviously John is a believer in turbos, but in this case he believes his system is particularly suited for the Shelby’s 5.2-liter engine.
A turbo system will not pull on the front of the exotic Flat-Plane Crank.—John Urist, Hellion
While the GT350 system is similar to its Mustang GT cousin, John did have to use the latter system as a basis to create a new, Shelby-specific twin-turbo system.
“We had to change a few pipes in the kit to adapt to the amazing factory headers that our kit retains,” John said. “The design and fitment remains ergonomic and clean. The proper component position and routing is the same as our GT kit, and connects to the factory exhaust.”
The first car to receive this kit was owned by a local racer, who offered up the car as a showcase for the kit’s television debut. Because he is such a good customer, John offered to fortify the car’s engine, reinstall the kit and tune it up for big power. To do so, of course, he would need more robust engine parts, so he turned to his supporters for some custom pieces.
Built Boost Tough
“This beautiful GT350R is owned by racer Jim Guthrie here in Albuquerque, New Mexico. We have already made amazing power with this car in stock form, but it was time to take it to the next level,” John told us. “Jim and I decided to order custom pistons from Arias, and custom rods from Carrillo to replace the factory units. With an engine like this, these are the two weakest links.”
While many might find it daunting to open up a Voodoo engine, John has long built his own racing engines, so he was game for the challenge. He did want to approach the upgrade like a regular guy would, so he left the crank in place and added direct-replacement upgrades where they were absolutely necessary.
With a upgraded rotating assembly, this engine will now be able to handle well over 1,000 rear-wheel horsepower.—John Urist, Hellion
“We decided to leave the block untouched with the factory spray-bore lining. In our experience this finish is reliable to 1,000 horsepower,” John explained. “When we go over 1,000 rear-wheel horsepower, we recommend having Modular Motorsports Racing sleeve the block with high-horsepower sleeves. MMR builds our high-horsepower engines such as Melissa’s record-setting 2015 GT engine.”
The Supporting Cast
Once the new engine was built, John installed a McLeod RXT clutch and reinstalled the turbo system. A big-power combination was ready to roar, but it would need more fuel than the factory system was designed to support. Amazingly, the solution for four-digit horsepower was simply a set of larger injectors and a fuel pump voltage booster designed for the GT350’s stock dual-pump system. He topped it off with a custom calibration built using HP Tuners gear.
“The initial calibration that we send in our system is capable of handling this power increase with only the JMS dual-pump FuelMax to boost fuel supply, which is very critical in applications over 750 rear-wheel horsepower with our 95 lb/hr injector upgrade.” John said.
The Mustang GT System
As we mentioned in the main story, Hellion Power Systems also offers an Eliminator Twin-Turbo system for the 2015 Mustang GT. This kit comes standard with the same vertical-flow, dual-inlet intercooler; TurboSmart VEE Port bypass valves and 55mm turbos as the GT350 kit and it will deliver similar performance results assuming the car has the engine mods and support systems to feed four-digit horsepower.
With the new built, boosted and fueled combo in place, the turbo Voodoo engine exceeded the expectations that Jim had in mind. Not only did it blast out over 1,000 rear-wheel horsepower, but it put down four-digits worth of torque. Being the 5.2-liter engine doesn’t have a rep for being a torque monster, so these numbers are all the more impressive.
“With the technology advancing at an all-time high, these Precision 55mm units make the power of older 62mm units with an increased spool time,” John concluded. “The crushing torque that the Hellion kit provides really wakes up the lack of low-end power that the GT350 is known for. This is due to the quick response of the 55mm turbos.”
“In addition to the engine upgrades, we installed a state-of-the-art McLeod clutch to help handle the extra power and torque,” John said. “It is a bolt-in unit and is easy to install.” Knowing the goal was exceeding 1,000 rear-wheel horsepower, he installed the RXT twin-disc clutch (PN 6337807M).
If you want even greater power and are willing to fortify the engine even more by adding block sleeves, you could always add Hellion’s optional turbos and really go deep into the four-digit range.
“We have made 1,160 rear-wheel horsepower with the twin 55 turbos on conventional 90-degree-crank cars, so we do not see any reason that is not attainable with the Voodoo engine,” John added. “We have a couple options for larger turbos if over 1,500 horsepower is desired.”
Ford may have never intended for the Shelby GT350 to see boost, but the Voodoo 5.2-liter engine sure seems to love 18 psi or so as long as it has the proper supporting gear. If you are willing to run 9 or so pounds, you don’t need to fortify the engine and the performance is still pretty impressive. Either way, you’ll have one of the most fun cars on the road.