Ancillary items that impact performance and aesthetics under the hood include an HKS Circle Earth ground kit, GReddy breather tank, GReddy pulley kit, ATI Damper, Blitz Radiator hose, Koyo radiator and a Garage Defend Cooling plate in addition to the precursory oil and radiator caps.
Tuning the beast was a long-term process that engaged the entire SP crew and really put the hurt on the company's four-wheel Mustang dyno that was installed in preparation for the all-new Skyline due out in 2008, as well as tuning of the R33 and other all-wheel-drive platforms. SP has carved out a niche as expert HKS F-CON V-Pro tuners, earning the coveted HKS Certified Pro Dealers stamp of approval. The Skyline's tuning electronics array consists of a V-Pro, an HKS A/F Knock Amp and Blitz I-Color boost controller.
The V-Pro is a standalone system that's melded into the engine management loop, much like a piggyback computer. It offers 32x32 resolution mapping to precisely address both fuel and timing curves and deliver the vital combination of big power and everyday driveability. SP Engineering tag teamed the V-Pro with an HKS A/F Knock Amp that tracks engine knock and air/fuel ratio, the two most critical variables when tuning any performance powerplant.
The A/F Knock Amp displays knock and, when properly outfitted, A/F ratio in real time. The unit can be programmed to provide visual and audible warnings so a dyno pull can be abandoned before the engine sustains damage.
SP selected the Blitz i-Color SBC boost controller to harness the boost because its sequential solenoids were up to the challenge of combating overboost while also maintaining a constant peak, which his no easy feat when the T51-R SPL is pushing 2 Bar of boost. Further, the i-Color can be set to Auto Boost and staged boost levels can be programmed. The unit can also monitor a number of inputs on its vivid color display.
These 'three amigos" of tuning threw quite a party as the final tally put the RB26DETT at 957 wheel hp and 710 lb-ft of torque. Alex was quick to point out that 2 Bar is well within the unit's efficiency. In fact, he said that at the turbos maximum 2.5 to 2.6 capability, 1200 wheel hp could easily be realized. But he points to self-preservation as one of the limiting factors. "We didn't really care about 'the number' because this was my daily driver," quips Shen, "Besides, if I went ahead and put up 1200 Ken Henderson would charge the shop screaming 'more power' and we would never see the light of day again." Henderson is a committed enthusiast is a popular contributor in the Supra community and his pristine black SP-built Supra produces 1162 wheel hp.
The GT-R's gargantuan thrust is funneled through a Hollinger sequential gearbox fitted with an OS Giken triple-disc clutch.
SP creations are fully balanced builds with the company's trademark attention to detail showered on all the car's component systems. Considering its legendary pedigree, the Skyline would get "extra credit" on attention under the chassis, on the body and in the cockpit.
The chassis relies on Tein Type RE coilovers and Cusco roll bars to provide point-and-shoot handling characteristics. The RE coilovers are wired into Tein's Electronic Damping Force Controller [EDFC] that uses motors positioned atop the damper to control its dampening rate on the fly in real time. The unit can store three settings for easy recall, control 16 degrees of adjustment and alter front and rear settings independently. Stopping power has been enhanced with Brembo components and the GT-R's rolling stock consists of lightweight 17-inch Volk Racing TE37s and 275/40-series Mickey Thompson ET Street rubber.