Tommy kaira ZZII - history
Meet up close your Gran Turismo hero
extracted from "The Phantom Sportscar - Tommy kaira history"
[...] Back to 1999, after the ZZ production was stopped for homologation issues, Tomita and Kaira wanted to persist in achieving the goal of producing their dream car, driven by a warm welcome from the press for the first car entirely conceived on their own.
The new concept was to sell a car solid and effective enough to be used in GT championships (FIA or All-Japan) by changing only the wearable, ie tires, discs, pads and clutch, adding a wing, and eventually replacing the engine depending on the category, varying from 2 liters to 3 liters and a half of displacement (but there could have been fitted a V8 and a V12, too). Tomita was aiming not only to Japan, but also and especially to Europe and the United States.
The simplicity of the car and the use of non-exotic components should have limited its price tag to under 10 million yen (equal to 95 thousand dollars in 2001 and 135 thousand dollars today, considering the purchasing power). Furthermore, the better interior's and construction's refinement made it a complete all-round car without excessive sacrifice.
Being the evolution of the ZZ, they named it ZZII. The presentation should have taken place at the 2001 Frankfurt Motor Show, but that didn't happen as probably the car was not ready yet, so the ZZII was first shown at the 2002 Tokyo Auto Salon, some months later.
They started from the well known extruded-aluminum lightweight chassis and they installed their workhorse taken from the R-Z, an inline six twin turbo with 530PS and lots of torque.
The result of this transplant would have been a 550PS berlinetta able to clock more than 330km/h, keeping its weight under the ton and covering nought to sixty in two seconds and eight tenths.
For instance, the Nismo BNR34 Z-Tune can achieve 330kph with fifty less horsepower, a 20 less Newton metres of torque, half-a-tonne more weight, and the aerodynamics of a brick. The ZZ-II could do better for sure.
Also, for comparison the B-Engineering Edonis, another stillborn supercar, clocked 360kph but, if it weighed as much as the ZZ-II keeping its own power to weight ratio, it would have had between 500 and 610 BHP, depending on the actual weight of the Tommy kaira.
In picture: a test-bed chassis for testing and validation of components and parts.
The recipe does not end at massive power outputs. The hybrid chassis of the ZZ (welded tub of square-section extruded aluminum and steel-piped subframes, always produced in the United Kingdom) was modified. The manufacturing process remains the same, with welded square-section aluminum extrusions, but the tub gets a rounded shape to better accommodate the occupants, avoiding to rotate the seats inwards, guaranteeing anti-intrusion protection at the height of the seat thanks to its walls. Furthermore, the frame was streched, especially at the rear, to accommodate longitudinally, turned by 180°, the new six-cylinder, which was longer for sure than the transverse mounted SR20, leading to an increase in wheelbase by 275mm.
This time, the front frame is designed to meet the safety standards in impacts for large production cars.
The cooling system is enhanced, with the use of a front radiator tilted about 60 degrees that draws from the front vent, with the vents in the rear pillars of the roof, at the end of the inward-facing windows (as for the F40).
The intercooler feed is helped by three air intakes: two of them are made with scopes starting from the windscreen and ending at the back of the farther end of the engine bay. Their section gets narrower towards the outside as they get closer to the engine, to increase fluid speed. This way, between them another vent is obtained, and it's shaped like a big NACA duct, with a giant suction area just behind the engine, which in turn can bee seen through the tiny rear window.
The result of this is that the engine can take advantage of the full width of the roof for air feed, but without the aerodynamic issues of a full width scope.
The heart of the berlinetta is the same of a Tommy kaira R-Z: an RB26DETT, still a twinturbo, modified with an 87mm bore and a 75.7mm stroke, bringing the displacement to 2700cc, using forged aluminum pistons with titanium-coated rings, new connecting rods with inverted H section, lightened and balanced crankshaft produced in England, racing ignition, polished valve seats, metal head gasket, re-profiled cams with higher lift and improved timing, reinforced valve springs, new ECU, improved intercooler with Skyline N1 water pump, new Garrett turbocharger, increased injectors and fuel pump, 3.5" catback, Fujitsubo exhaust and Tommy kaira terminals.
All of this allowed to reach 550PS at 7500RPM and about 540Nm @ 6000rpm. The engine revs didn’t go past 8000 because, as Kaira said, the peak was reached before, unlike what Gran Turismo games suggest. Maybe the 9000RPM limiter was true for the first iteration of the concept, which was probably planned to have 600BHP and RWD, as in Gran Turismo 2.
Unlike the BNR34, here the RB26 engine is not placed above the axle, so a new sump had to be designed, due to the fact that the differential wasn’t placed anymore to the side of the sump itself.
The six-speed transmission is the same Getrag borrowed from the Skyline GT-R in bulk with the differentials, together with the electronics of the ATTESA E-TS Pro system, appropriately modified since the engine is turned 180 degrees together with the gearbox, which therefore has an upside-down pattern (notice the gear lever in first gear). Due to the different diameters of front and rear wheels, a modified transfer case was designed to address this problem.
The new engine location allowed the differentials to be placed independently from the Skyline layout, so they were carried over from the GT-R without being reversed together as it happened to the gearbox.
The suspensions are double wishbones in pushrod configuration, at the front with coils (Bilstein personalized by Tommy Kaira) arranged horizontally under the bonnet. The coils are accessible by removing the front bonnett, shaped alike the McLaren F1’s one.
The wheels are the Tommy Kaira Pro-R forged in magnesium alloy, steered by a rack and pinion system without power assistance. Dimensions are 245/40 ZR 18 in front and 285/30 ZR 9.5x19 JJ at back. Currently the car wears 225mm tyres at front and 295mm in the back.
The brake system consists of four AP Racing self-ventilated slotted discs and PFC pads, approximately 360mm and 6 pots at the front and about 320mm and 4 pots at the rear. The front discs are cooled by the two triangular air intakes on the sides of the grille.
The bodywork was planned to be in CFRP, but the body of the only existing prototype is made of FRP; the fiberglass panels are coated with a black gelcoat, as can be seen in the pictures taken at Meisan workshop of Fujio Yagi in Kyoto, a business which was specialized in FRP and polycarbonate products manufacturing. The weight figure of 1000kg probably refers to the version with carbon fiber bodywork, while the prototype with fiberglass panels should weigh just a shade below 1200kg, as it was reported on AUTOBACS website. Some assume the 1000kg figure is related to the car with fiberglass bodywork, so the weight of the one with carbon bodywork could have been 900kg.
The body reaches 4 meters and 30 in length, 1 meter and 96 in width and 1 meter and 19 in height.
The aesthetics were designed by Design Apple, a design and architecture studio of the Nishida brothers in Kyoto; of the two, Noriyuki was already designing bodykits for Tommy Kaira since 1998. You can see him in the last picture posing with the ZZ-II.
The style is probably one of the most remarkable sides of the ZZ-II: despite 20 years have gone by since the approval of the final design on 18th December 2000, aesthetics haven’t been affected too much by the passing of time, especially taking into account that today there is a herd of angry looking supercars out there.
In that time, at the turn of the two millennia, supercars didn’t look mean yet, in contrast to what we are used to see today. The "competitors", the Ferrari 360 Challenge Stradale, the Porsche 996 GT3, the Dodge Viper GTS, the Aston Martin Vanquish, even the Lamborghini Diablo, are fluffy lambs compared to such a sleek, aggressive, tense and sculpted design as the one of the ZZ-II.
Kaira overseen the designing process. The first concept was a proper racecar with number plates. One of the key features of the ZZ-II was the light and stiff aluminium tub frame, so, as you can see both in drawings and in early models, a portion of it was intended to be exposed on the side of the car. The same goes for the upper part of the chassis, with exposed roof arches.
However, later the concept was slightly turned into a more refined supercar, so the frame had to be hidden. The core of the design would become tense lines, edges, and complex surfaces.
As I said earlier, Nishida was previously appointed with the second gen ZZ,, called ZZ EVO, which was intended to be offered in a coupé version, but that wasn’t ever finalized.
A couple of years later, after the concept of the ZZ-II veered from the hardcore track car to a refined supercar, he recovered some of the drawings of the ZZ coupé and evolved them to fit the layout of the ZZ-II.
Characteristic elements are the large pointy black headlights that extend three-dimensionally on the wheel arch; the raised central portion of the front end, bulked in order to accommodate the radiator; the two unusual split airscopes on the roof; the short, wide and wrap-around rear end, pointing upwards like on sports-prototypes, with its double circular headlights arranged on two levels; the large air diffuser with two exhaust on its sides, the side air vent that digs a groove up to the front wheel...
Oddly, the Gran Turismo saga features the ZZ-II in its fleet since the second chapter, following the styling developments which are comparable to the sketches by Design Apple (of December 2000), but from Gran Turismo 3 onwards it no longer updated the polygonal model of the car, which remained to the 1:5 scale maquette of lato 2000. Therefore on the Polyphony Digital's series the ZZ-II never got featured as it was manufactured.
Founder Yoshikazu Tomita applying the Tommy kaira red turtle badge on the ZZII in 2009, when it was brought back to him