When the Nissan GT-R was first released, I wasn't concerned with the front end of the car- the engine, it was the back end, the transaxle that had me concerned. The
GR6 is a dual clutch electronically controlled gearbox, that in the R35 includes the transfercase, the transmission control, the dual clutches, the gearbox itself, and the rear end. A complicated piece, and if you do 26 wheel hopping launches in a row with
LC1, known to shatter first gear. A well known transmission specialist from the DSM world,
John Shepherd starting working on fixes for the Nissan GT-R transmission, and eventually bought his own car for shop testing, running as fast as 9.42 on DOT tires.
One of the first specialists to respond to this need was John Shepherd of Shepherd Transmissions, Inc. A long-time fan of AWD performance, Shepherd embraced the GR6 and studied the factory’s improvements year-to-year. “Many early problems were blown out of proportion,” Shepherd admits. “The most common problem is the weak first gear. Other common issues include circlip failures, piston seals, damaged selector pistons and synchro sleeve failures. Today, we have solutions for all of these issues.”
With only 180 miles on the odometer, Shepherd wasted little time getting the V6 engine into the Shepherd Transmissions workshop. Its cylinder heads took a trip to Head Games to receive port work and a complete Ferrea valvetrain. When the finished heads returned, ARP head studs secured them to a newly fortified VR38 block. The engine now features a balanced crank, courtesy of Canton Automotive Machine, Carrillo connecting rods and AMS-spec JE Pistons. AMS-spec Kelford camshafts actuate the valvetrain providing improved lift and duration.
For more on this article and everything else in Issue 122, get your DSPORT Magazine Back Issues online here!
If you haven't ever seen John's Talon, check out the video below. 7.70 @ 191 mph, and manually rowing the gears.
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