Nissan Skyline  R34

Glorious pics, great diagrams and cutaways - and best of all, it was for the current model (R34) Nissan Skyline GT-R! But there was a downside. As you'd expect for Japanese new car buyers, the booklet is mostly in Japanese...


But reading between the lines a little, scrutinizing the pics and diagrams, and looking for English numbers in the text means that there's some stuff that I could pick out. Stuff like this.

One of the features of greatest interest to me about the R34 is its aerodynamics. With some variations, the driveline - and arguably, even the car's appearance - hasn't undergone revolutionary improvement in the decade or more since the R32 dramatically appeared. But in that time the aerodynamics have certainly altered for the better!


The R34 features a rear wing, deep front spoiler and side skirts - like any ol' sporty car these days. But it also has something that only a mere handful of road cars have - a fully aerodynamically developed underside. But let's start at the top.


The two-element rear wing has the trailing aerodynamic surface adjustable for angle of attack. This, you would expect, allows the adjustment of rear downforce. And, as the angle of attack is increased, you'd also expect the drag coefficient (Cd) to increase.


Both of these views are supported by a graph in the booklet, shown here. It indicates the decrease in rear lift (CLR) at different wing attack angles, with the coefficient of drag (CD) increasing as lift decreases. The comparison with the previous R33 model shows significantly less rear lift (ie more rear downforce) with no greater drag penalty than the earlier car.

But it's underneath the car where the real action is. At the front is an undertray that extends the full width of the car prior to the wheels, then back under the engine. This smoothing of the airflow helps the front spoiler/splitter work, in addition to making the airflow passing under the rear undertray less turbulent. What rear undertray? you ask.

A full rear diffuser is fitted. This comprises a flat panel that is angled upwards towards the rear of the car. It is sub-divided into three areas of flow, with one path partially blocked by the protruding muffler and tailpipes. The idea of a rear diffuser is to accelerate the air around the throat - the part of the device that has the initial change from being flat to being tilted upwards. This higher speed flow creates a low pressure, pulling the car downwards.

 

So what do these aero devices do? The graph indicates that without the aero devices, the front axle lift rose to as much as 40kg at 180 km/h, while with the devices, the front axle lift at 180 is about -30kg and the rear axle lift is about -25kg.

One of the odd things about the Japanese supercars like the GT-R is that the agreed power limit of 280hp puts manufacturers into a quandary. How can they claim engine improvements in subsequent models without exceeding this limit? The GT-R has always been rated at 280hp, from R32 to R33 to R34 models. Sure, you can talk about improved mid-range torque, but what's that mean, anyway?


To counter this perception, Nissan in the brochure have included this graph. It apparently shows second gear acceleration of the R33 and R34 GT-R models, from 20 km/h. As can be seen, the R34 comes onto boost noticeably earlier than the R33.

 

For me, one of the really great gee-whiz features of the car is its multi-function TV-style display panel. I won't say any more about it - just expand the picture below to see just some of the parameters than you can display. Gawd, I'd love to have one of those in my Audi!

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