Justin Humphrey Looking for 8s with his Twin-Turbocharged Two-Valve

Justin Humphrey has been a champion of the Two-Valve movement for a few years now. He’s had a supercharger on his New Edge GT with a six-speed manual and an automatic transmission. In the last couple years, though, he has swapped out the supercharger for a pair of turbochargers.

With a ProCharger F-1A on top of a built Two-Valve, Justin’s car made just short of 900-rwhp, but after an engine mishap, that’s when he decided to switch things up, and add the turbochargers. In it’s previous iteration, the car ran deep in the 9s, and so far with this combination, the car has already made 900-rwhp and been a 9.55 at almost 140 mph, “In horrible air, and blowing through the converter,” Humphrey says.

At the heart of Humphrey’s new combo is a Teksid 4.6 block with a Kellogg 3.75-inch stroker crank, Oliver billet I-beam connecting rods, JE pistons, and a 9.7:1 compression ratio. Up top are ported Trick Flow heads, a ported Reichard Racing intake, and 160 lb/hr injectors fed E85 by a Fore Precision triple pump fuel system. The turbo system was built by Humphrey at his new venture, Sudden Performance, and comprised of CG Fabrication forward facing headers, and a pair of Precision Turbo V-band 6262 turbochargers. Behind the 5.0 is a Mike’s Trick Shift 4R70W with a 4,000 rpm stall converter.

Out back is an 8.8 with 9-inch ends, Mark Williams axles, Eaton differential, and 3.73 gears. For wheels, Humphrey uses Weld Alumastar 2.0 17×4 up front with Champion 15×10 double-beadlocks out back. Traction is aided by Mickey Thompson ET Street Radial Pros in a 275/60.

Humphrey’s 9.55 taking place in not-so-great air, and blowing through the converter, he hopes both issues are solved when he attends the NMRA World Finals at Beech Bend Raceway in early October. Beech Bend, located in Bowling Green, Kentucky, at that time of the year, always has great air, and he hopes to have a new converter in the car by then, as well. “8s or bust in Kentucky,” Humphrey says.