Build Your Own R35 GT-R, Week 8

by akasakaR33
10 years ago

Summary of this week’s magazine contents:

1) R35 GT-R Story

The GT-R Proto – In Detail

The design of the GT-R Proto, based on a proposal by Hironaka Ono of Nissan Technical Center Advance Design Department, was clearly a step forward towards production from the GT-R Concept. While 90% of this design would make it into production, there are a few details where there are differences – either because those items were for the show car only, or because the details had yet to be fixed for the production car.

The front fascia of the “GT-R Proto” – the grill area is the same as the production car. But the upper grill design and the mount for the GT-R emblem are different. In the lower grill, the apertures for the oil coolers are similar, but slightly different to the production car. On the show car, the black areas are carbon fiber, and apparently the entire bumper itself is carbon fiber too. However on the production car, the bumpers were made out of urethane (note: I think they mean ABS plastic?) – the reason is not due to the expected high cost, but for pedestrian safety. A fully carbon fiber bumper would be very stiff and rigid, but urethane is soft and potentially less damaging to a pedestrian that gets hit in an accident. Finally, the black carbon areas under the headlights – these had openings for brake cooling, but aerodynamic tests showed that they were unnecessary and so were removed from the production car.

Also, the shape of the bonnet is different – while the road car’s bonnet extends between the headlights fully and has square edges, the Proto has rounded edges and is not as wide. Additionally, the ducts used to cool the turbos were rectangular, and these were replaced with NACA ducts in the production road car.

The shape of the headlights are also different. On the Proto, the headlights are stacked vertically, while on the road car the lights are arranged side by side. Also note how the angling off at the rear is reversed on the road car.

Looking at the body design, the road car is mostly the same as the Proto, except the GT-R emblems are not present on the Proto. The side mirrors on the Proto were dress up for the show car only, and similar the show car has no door handles, only a button where the handles are.

The rear appears to be, other than the spoiler, much the same, but even here there are several differences. First, on the Proto, there are no side indicators. In Japan these are clear, for export models these are red. The 4 round tail lamps on the Proto appear normal, but on the road car the outer two are LED 12 bulb units. The space for the license plate is narrower on the Proto – on the road car this space had to be widened to accommodate the wide number plates used overseas. The rear under diffuser – on the Proto this was made of carbon fiber and had a center back foglamp, on the road car this is urethane. What’s interesting of the rear of the Proto is, no “GT-R” emblem is found. This was done to draw the eyes to the “GT-R Proto” license plate.

The rear spoiler that made it to production is totally different from that on the Proto – apparently this was a design element that was worked on until the last minute.

2) Mechanism and Factory

1.2 Bar, 23 Degrees C Clean Room

The Nissan Yokohama Factory is at the same location in Yokohama, Kanagawa Prefecture, where Nissan was established in 1933. In 1935 Nissan began Japan’s first mass production of vehicles here. Currently, the factory is a “unit” factory, making engines and suspension assemblies.

The engines the factory produces are the 4 cylinder QR series and MR series. In the past, this factory produced the L series, as well as the straight 6 RB series, including the previous GT-R generation’s RB26DETT. The current “sporty” engine, the VQ series are made at the Iwaki plant in Fukushima Prefecture. However, while similarly a V6, only the VR38DETTs are made at the Yokohama factory – for special reasons.

While generally, engines are made by several employees manning a moving conveyor belt production line (and the RB26DETT was made this way too), the VR38DETT is different. Each engine is constructed by one man, and then bench tested, similar to how racing engines are made.

The VR38DETT is made only by 13 “Takumi” (Japanese for “Craftsmen”) selected from the elite ranks within Nissan. Each Takumi not only has to be a Nissan mechanic, but also possess a national first class qualification, and then pass 3 different tests within Nissan.

The Clean Room, newly constructed for this purpose at the Yokohama factory, where these Takumi work, is kept at 23 degrees Celsius, with a humidity of between 55-57% at all times. These conditions are considered ideal for assembling the metal parts of the engine, in that the parts can be put together as close to specification as possible. New parts being delivered arrive in a two stage airlock, where they wait 1-2 hours to acclimate to the environment before being released into the room.

Further, the Clean Room is kept at 1.2 bar – this is to ensure that, despite entry by people and parts, no outside contamination is brought in.

All of this is to avoid the typical small variances that appear as a result of normal engine assembly. Because the GT-R engine is a high performance engine surpassing the specifications of other engines, nothing can be tolerated that would denigrate this performance. Further there is a spirited competitiveness amongst the Takumi, which results in an improvement in the level of precision on a daily basis. For example, for “friction” the engine met specifications, but a Takumi, turning the engine by hand, was able to tell something was amiss. When said engine was disassembled and inspected, minute particles were found. Showing how the human Takumi was superior to the “precision” of a machine.

3) Racing Legend

Global Debut for the GT-R – the FIA GT1 Spec. – the other racing GT-R

The article describes the racing debut of the GT-R overseas. Specifically, the FIA GT spec GT-R at the UK’s Silverstone Circuit in May 2009, and gives a short history of the FIA GT series, with the GT1 and GT3 categories.

The team was run by Gigawave Motorsports, and the drivers being 2008 Nismo development and ace driver Michael Krumm (dispatched by Nismo), as well Darren Turner, who had GT1 win experience. Having undergone shakedown tests from December of 2008, the GT1 spec GT-R made its “official” debut during a press day in April 2009 at the Paul Ricard circuit in France. The GT-R drew a lot of attention during the press day event, being the first Japanese entry in the FIA GT series.

At its debut race in Silverstone, the fans were out in force. This GT-R had, during 5 shakedown tests in the previous year, accumulated over 6000kms of mileage. The car was in steady development, and had changes made even after its appearance at Paul Ricard – note the louvers on the rear side of the front fenders, for example.

Also – the GT-R was designed with the 2010 regulations in mind – the only other car on the track in April 2009 similarly specced being the Ford GT – which however was showing similar performance (but not to the extent of widening any gaps) to the GT-R, much to the relief of the Nismo staff in attendance. Unfortunately, the GT-R (having started in 11th position) while running in 8th place suffered rear suspension trouble and was forced to retire from the race – nevertheless the potential was clear!

4) How to Build

This week: Attaching the two prop shafts

Quote from Mizuno-san: “We made the main prop shaft out of carbon fiber, which is as strong but lighter than steel. It contributes to a reduction in noise and absorbs vibrations. The front prop shafts are made of smaller diameter steel.”

There are 4 pieces, which add onto the transaxle from last week.

5) History of Nissan

This week: 1939 Nissan Van Type 81

Nissan founder Samekawa’s strategy was to first build small cars under the Datsun brand, and then, after increasing production capacity, to build larger, Western style large vehicles. In 1939 Nissan introduced the Type 80, which ended up being more than 80% of the vehicles Nissan made, contributing greatly to its bottom line. Buyers were the military, government, large transport companies, and bus companies.

The Type 80 was known for its “cab over” desing which allowed for large cargo space, hence its popularity. However, with the increased weight on the front wheels, and difficulty of access to the engine for service, Nissan introduced, after a breakneck 6 month development program, the “bonnet type” Type 180 in 1941. It used the same engine as the Type 70 passenger car, and afterwards increased engine volume, gained OHV, and eventually, this engine block was used in some form until 1986. Further this block served as the basis upon which Nissan’s straight 6 engines were made.

A commercial vehicle that supported Japan’s society and economy.


Next Week’s Part – The radiator and other engine bits.