Build Your Own R35, Week 10

by akasakaR33
5 years ago

Note: apologies for the gap/delay in uploading. The excuse is “life” LOL. Will catch up soon!

Summary of this week’s magazine contents:

1) R35 GT-R Story

Nurburging in 7 minutes 38 seconds in a production car!

The Moment the “Door to the World Opened”

March 2007, the first prototypes roll off the actual production line – the “Product Lot” test cars. Up until now, all the cars, even the Pre-Production lot cars, despite being nearly identical to the mass produced cars, were all hand made in a special factory. But these Product Lot cars were made at Nissan’s Tochigi Plant, by the same team of workers who would assemble the production cars.

However, when the first Product Lot cars were being made, a problem arose – when the body/chassis was tested, it failed to meet the specs of the hand made cars. Precision is key for the chassis, as this is the basis of the high performance of the R35GT-R. With the body being made at a level of precision unthinkable in a normal car, which results in the high structural rigidity and allows for precise movement of the suspension.

When Mizuno-san heard about this, he assembled all of the Tochigi plant assembly workers, and made them all each ride along in the first Product Lot car. Then, after welding was done to one part of the car under his direction, they were all taken for another ride – and everyone was amazed at the difference this made to the responsiveness of the car. They all then fully realized how important the fitment of the panels were as well as how their welding could absolutely change the car. As a result, the precision in the R35’s body panels is under 0.2mm whereas a normal car is 0.5-1.5mm.

So it was the first of these Product Lot cars that was brought to Nurburgring. Although the time attack took place on the last day of tests, with only two laps, the car was able to mark an unofficial lap time in the 7 minute 30s. Then on September 24 – right before production began – the last Product Lot Nurburging Attack. Sport Auto, a German auto magazine, was on hand to witness.

The track was partially wet, temperature 16 degrees C. The number “33” car began the run. At the wheel was Toshio Suzuki. Awaiting him included a blind corner that was taken at full speed, mid-corner speed being 220km/h, and upon exit from the corner the speedo showed 264km/h. Winding roads with turn upon turn at 150km/h, and a wet patch that Suzuki cleared with little drama.

In the end, the time set was 7 minutes, 38 sec 54. The “33” car had surpassed the 911 Turbo, having become the fastest production car to lap the Nur on radial tires.

Note: chart on bottom of page 7 shows how the Nur lap times improved with newer GT-R models, culminating in a time of 7 minutes, 24 sec 22 for the model year 2011 car. Improvements were made not only to engine output but suspension and brake cooling.

2) Mechanism & Factory

Page 8:

Blocks built with extreme care – resulting in not a single problem on the market

In the last article we saw how the crankshaft was assembled into the block – this week it is the pistons and the conrods. Waiting on the bench are pistons that match the cylinder bores (having been precisely measured, and all managed by computer).

First step is to assemble the conrods to the pistons by way of extremely precise piston rings – the pistons are heated beforehand to make insertion of such pins easier. While the Takumis of the Yokohama engine plant make this look easier, it is actually a very difficult task, with the tolerances of the pin and the holes being extremely tight.

Once assembled, then the pistons finally get put into the block. Using a special tool, the rings are held in while the cylinders are inserted. After that they are attached to the crankshaft, and then the crank is turned by hand to test for any irregularities.

Photo – in order to facilitate insertion of piston pins, the pistons are placed on a hot plate heated to 55 degrees C.

Page 9:

Upper left – piston in left hand, piston ring on left wrist and use the right hand to get ring on piston. Any mistakes and the rings are thrown out..

Upper right photos – left photo – metal bearings put onto conrods. Right photos – Takumi follows LEDs indicating which bearings to assemble in which order – all computerized and on display.

Middle four photos – from left – conrods and pistons come together. Clips are inserted. Blue box – piston pins are checked by special machine.

Bottom right three photos – right photo – conrod bolts are tightened using special machine. Order and torque are automatically entered into the computer. Bottom – using a special sheath on the cylinders to hold rings, and make insertion into block easier. Left top – Special tool makes insertion of pistons into block easy.

Bottom left single photo – when all work is finished, the last step is to turn the crankshaft by hand. Any strange friction and the block is disassembled and cleaned and rebuilt.

3) Racing Legend

Coming off the 9th place finish at Stadt Oschersleben, despite the bad weather, expectations were raised for the next race the GT-R FIA GT car participated in, the 4th race of the 2009 season, the 24 hours at Spa. Recall that the 2009 season was not an official season for the GT-R, which makes this performance quite amazing.

Again chosen to drive were Nismo Works driver Michael Krumm and GT Specialist Darren Turner, this time joined by back up F1GP driver Anthony Davidson. Meanwhile the racing GT-R had amassed more than 10,000kms in racing mileage, and the previous rain race was a simulation of sorts for Spa.

In practice Thursday morning before the race Turner set the 4th fastest lap times, but it began to rain that evening during the official qualification runs. Krumm set the best lap time before the rain prevented any other runs. Thus the car began at 8th place at 4 pm when the 24 hour race began.

As the race progressed the team fought its way up to 4th place, until drivetrain difficulties forced a return to the pits. While repairs were made, this resulted in a loss of nearly 1 hour and 30 minutes. However, with the need to continue running to collect data, the team had no choice but to keep going. Amazingly, once the car was back on the track, it ran trouble free and the team finished in 13th place. This kind of performance, and the data obtained, would be useful in the car’s official participation the following year.

4) How to Build

This week: Assembling the Intercoolers.

Quote from Mizuno-san: “The intake air compressed by the two turbochargers gets very hot. A larger intercooler is needed, but in the GT-R a left/right bank of independent intercoolers is used to improve response.”

Note: Upon completion of assembling these parts – the two remaining screws are used to bolt this intercooler assembly to the body in Vol 62.

Page 14:

Explains the theory of how intercoolers work (by cooling hot intake air, thereby making it more dense, etc.) The Nissan GT-R has, matching the 2 turbos, a left/right bank of independent intercoolers for the independent intake system. This system results in the best power, response and fuel economy. (At full throttle the air temperature reaches 170 C).

Oil cooler- looking at the car from the front, one can see the oil cooler on the left side.

5) History of Nissan

This week: 1938 Datsun Type 70

In 1936 Nissan began building, under license to the Graham Paige company, a large sized passenger car based on the “Graham Crusader.”

5500 units of this type 70 (Sedan and Phaeton) were built between 1937 and 1943, with all orders after 1939 strictly on a procurement basis for the military and government agencies. Price at the time was 4000 yen, about twice of a Datsun.

The engine was shared with the type 80 (side valve), 6 cylinder. The car had front safety glass, wipers were vacuum operated. Seating for 3 in the back, with 2 additional jump seats.

After the war, Japan did not build another large passenger car until the late 1980s. And the customer base changed from the military and government to wealthy individuals and corporations.


Next Week’s Part – Assembly of the left rear suspension.