Kobayashi-san, the owner of this time-attack–oriented GT-R, has done what every car enthusiast out there dreams of doing—building their dream project car. What probably differentiates him from you and me is that he has actually done it, making sure that every single detail is the best it could possibly be. The result is without a doubt one of the best BCNR33’s ever created. This car impressed us to no end when we dropped by the Do-Luck HQ in Yokohama to check out and have a chat with Ito-san, Do-Luck’s president, founder, and the man entrusted to finely tune the Skyline’s engine management.
Kobayashi is really only interested in one thing, and that’s achieving the fastest time possible at Fuji Speedway. Like many time-attack guys, his passion has unavoidably turned into obsession. Rather than let his obsession span out over a lot of years he addressed the whole car in one fell swoop. Mind you, it has been a long time in the making. Things tend to take a long time when you tackle every single part of the job yourself. Then again, as the saying goes, “If you want a job done well, do it yourself!” Owning your own machine shop sort of gives you an advantage—gross understatement, we know—but having the means is half the job. It was the underside of the car we checked out first as Ito kindly put it on one of his lifts and raised it up. We have probably never spent so much time admiring the underside of a car as much as we did with this R33. As you can see from the pictures, you can sort of understand why. First up was the chassis. Kobayashi stripped the car down to its bare shell, taking his time to remove all unnecessary ancillaries and sound deadening before going wild with the spot welder. Strategic areas of the unibody were re-welded to help increase stiffness, followed by one of the most serious rollcages we have seen on a JDM car—admittedly an area the Japanese are always a little behind on. The thick-gauge pipes were welded in place and gusseted to the pillars for extra bracing but it’s the actual titanium crossbars that close the ’cage around the door openings that caught our attention. Titanium is never really used in rollcage fabrication due to its softness, but Kobayashi wanted to add a touch of uniqueness to his car. Plus, he likes titanium, so who are we to judge. With the shell stiffened up and completed, it was the suspension that he turned his attention to next—and an area we really appreciated while underneath the car. All links were redesigned and custom fabricated, adding adjustability so that the geometry could be finely tuned according to track, available grip, and performance. Billet aluminum roll center adjusters were also part of the complex modifications, a critical detail for any serious suspension upgrade. Custom valved and set up Aragosta adjustable dampers followed, mated both front and rear to 18kg/mm Swift springs. These are still not fully dialed in; the car has only really had one shakedown test at Fuji Speedway since being put together, so spring rates are something that may well change. Braking was an area on which absolutely no compromise was made; Kobayashi, like anyone who has ever driven at Fuji, knows all to well what a hard test this challenging track is for brakes so he went with the best out there. Sitting on custom billet and anodized brackets that he designed and machined are a set of Super GT–sourced AP Racing calipers, six-pots fore and four-pots aft. These forged monoblock beasts are not only extremely light, but they also only accept thick endurance pads. The rotors, too, were custom made, 390 mm up front and smaller 356 mm at the rear, featuring the same sort of curved slotting as you often see on GT500 and GT300 racers. The one-off details continue with the brake cooling ducts and even a custom billet oil filter relocation bracket that moves the filter canister into an easier-to-reach location. This takes us to the engine . . .
While circuits like Tsukuba with tighter corners call for a more responsive and explosive lower to mid-rpm range, Fuji is a bit different. The faster layout means that engines can be built to more extreme specifications, which is precisely what Kobayashi did. Selecting the best of the best, he began to assemble his N1-based motor by hand, after first honing and boring out the block to accept the larger diameter of the HKS forged pistons that make up the 2.8L stroker kit he chose. This comes with H-section connecting rods and a fully counter-balanced billet crankshaft that pretty much creates the bulletproof bottom end you need to have on a car that gets driven to the max all the time. The capacity increase to the oil sump guarantees that enough oil is always present to be picked up and circulated, helping eliminate oil starvation when the car pulls big g’s through the corners or under heavy breaking. Up top, Kobayashi ported and polished the intake and exhaust tracks to clean up casting imperfections and boost overall breathing. Valve gear upgrades followed with Tomei titanium retainers and Trust springs, all topped off with HKS 272-degree camshafts and adjustable cam gears. Supplying the big volume of compressed air is the Trust T88 single turbo conversion, which sits atop of the Trust headers, all controlled trough an HKS external wastegate currently loaded with a 1.5-bar spring. Seeing his skill at working with titanium, Kobayashi fabricated a big-bore 100mm front pipe and complete exhaust system to dump spent gases efficiently and without any sort of restriction. One look in the engine bay reveals other one-off touches that only such an accurately and passionately built engine would incorporate. Things like the titanium heat baffling over the T88’s “hot side” or even the special coating to the turbo itself, done as a heat insulator but also to boost airflow, are such items. One touch we really liked was the polished intake pipe, which arches outward to match the large diameter of the Blitz mesh cone filter it’s connected to. This joins more custom piping needed to mount the HKS intercooler in place, which all connects to the Trust intake plenum. Sard’s latest generation of multi-hole high-pressure injectors, most commonly used on the R35’s VR38, were selected for their accuracy and response rate. However, due to their shorter length and different design, they required a custom fuel rail, something that Kobayashi whipped up on his CNC machine. These 750cc/min squirters are kept topped off by a pair of Nismo fuel pumps and are all controlled by the custom-mapped F-Con V Pro ECU. This is where Ito of Do-Luck came in, putting in some serious time on the dyno to not only maximize power and torque, but also make the whole setup very responsive. Only a low boost setting has been dialed in for now, limited to 1.5 bar, but easily allowing the engine to churn out a healthy 750 hp. Aside from the fact that the motor can and will be running more boost eventually, Kobayashi managed to lap Fuji at 1:47.92, which puts him on par with the sort of times big-name tuners are achieving. With the cooling sorted out thanks to the custom radiator and oil cooler, it was the driveline that was upgraded next.
Every little bit helps when attempting to shave off precious tenths at the track, so dumping the stock five-speed box in favor of a six-speed Hollinger sequential was an easy decision—one we, too, would have taken on a “money is no object” build like this. The smaller and lighter box was fitted with an OS Giken triple-plate clutch and held in place with a custom crossmember that has been fixed onto the chassis on a pair of hard Teflon bushes. Even a carbon propeller shaft was fitted, shedding quite a lot of rotational mass and therefore boosting pickup and throttle response for that true race car feel. Along with the Nismo front and ATS rear LSDs, the final drive was also shortened to make full use of the handpicked gearbox ratios in the Hollinger. Kobayashi approached Hasemi Motorsport for help on the look of the car, a detail that like the rest of this R33 was completely driven by function rather than form. That’s why the N1 bumper up front sports a large integrated front spoiler/splitter section that extends and swoops upward around the corners of the bumper itself. A pair of canards is also added but the real downforce is generated through the dry carbon diffuser, which is so rigid and well braced underneath the car that it’s able to hold the weight of an average Japanese guy standing on it. More custom carbon parts follow with the aero hood and side skirts and, of course, the rather massive Super GT rear wing. To help heat escape from the engine bay, an air outlet, similar to the Nismo R34 Z-tune’s, was worked into the top corners of the front fenders, putting the finishing touch to what is one purposeful-looking GT-R!
It’s not until you open the driver-side door that you realize the doors are actually carbon fiber too, again helping shave more weight off the car and at the same time making the entry procedure into the tight cockpit that much more special. Spartan is the best way to describe the interior, which has been kept quite simple with the addition of a few modules here and there, like the air/fuel readouts on the carbon center console, the HKS EVC boost controller or the HKS lap timer, which still proudly displays the time of that first lap attack at Fuji. Kobayashi sits on a carbon-Kevlar–shelled Bride bucked and steers the car through the OMP race steering wheel, shifting sequentially through the gears via a custom gear lever and shift knob.
Once Ito turns up the boost Kobayashi has the potential to rival the fastest tuner GT-Rs at Fuji Speedway, cars like the ATTKD R34 and the Auto Gallery Yokohama R32. This very unique R33 is one Skyline we will be keeping our eyes on throughout 2013!
Behind The Build
Aiming to set the record at Fuji Speedway.
1996 Nissan Skyline GT-R (R33)
Output: 740 hp/513 lb-ft of torque
Engine N1 engine block; HKS 2.8L stroker kit (forged 87mm pistons, H-section rods, counter-balanced crank), F-Con V Pro ECU (Do-Luck tuned), 2mm metal head gasket, slide cam pulleys, camshafts in./ex. 272 degrees, GT-2 external wastegate; custom extended sump; Tomei Powered titanium retainers; Trust valvesprings, head studs/bolts, exhaust manifold, T88 turbocharger, heat coated turbocharger, titanium head shielding, intercooler, intake manifold; custom 100mm titanium exhaust system; custom intake pipe; Blitz mesh filter; custom intercooler piping; Nismo fuel pump x2, custom machined fuel rail for new-gen injectors; Sard multi-hole VR38 type 850cc/min. injectors; custom radiator and air separator tank; Apex oil cooler; custom oil catch tank
Transmission Hollinger six-speed sequential transmission; OS Giken triple-plate clutch; carbon propeller shaft; Nismo front LSD; ATS rear LSD; 3.7 final drive; custom transmission oil cooler; rebuilt transfer case
Suspension & Brakes Aragosta adjustable coilovers; 18 kg/mm Swift springs; custom adjustable suspension links; custom roll center adjusters; Nismo titanium strut tower brace; Super GT endurance racing AP Racing six-pot calipers front and four-pot rear; custom aluminum brackets; custom two-piece floating rotors 390mm front and 356mm rear, Performance friction endurance pads; custom brake ducting; AP Racing brake balance adjuster
Wheels/Tires 11x18 Rays Engineering Volk Racing VR-G2; 295/30R18 Hankook Ventus TD
Exterior Hasemi Motorsports N1 custom racing bumper, custom dry carbon lip spoiler and diffuser section, carbon canards, custom carbon hood, front vented fenders, dry carbon Super GT doors, custom aero mirrors, dry carbon Super GT wing
Interior Custom SCM420 multi-point rollcage; removable titanium side impact bars; Bride carbon-Kevlar bucket seat, seat rail; Willans racing harness; OMP steering wheel; Nismo dash; HKS EVC boost controller, Circuit Attack Counter, turbo gauge mounted behind center air vent; air/fuel meters; carbon-fiber panels for center console; custom shift lever