Text: Jude Morte / Photos: Brent Co | posted November 13, 2008 01:00
The Nissan Navara speed run
Now you would ask, "How can the Navara match a PC's acceleration, since by its very nature as a pickup it's heavier than a car?"
One answer is the engine. The 2.5L's turbocharged common rail direct injection (CRDi) inline four has a wide power curve. You enter the powerband's bottom end (roughly 1450-1700 rpm) early due to the very nature of diesel engines as torque monsters. Quick science lesson: A diesel engine's high torque stats are due to a high compression ratio - the ratio between the volume of the cylinder and combustion chamber when the piston is at the bottom of its stroke, and the volume of the combustion chamber when the piston is at the top of its stroke - and is achieved with heavier basic reciprocating parts (pistons, connecting rods, crankhshaft) than petrol engines. This provides smoother control over heavy loads when starting from rest, and allows the diesel engine to be given higher loads at low speeds than a petrol engine. Hence, quick acceleration potential.
Another answer sits on that long wand or slushbox stick nestled between front occupants, along with the solid metal bell housing mated to the engine block. The Navara's five-speed a/t and six-speed m/t setups are commonly found in sports cars, to increase fuel efficiency and further expand the vehicle's pace. It also prevents the unit from falling off the powerband's bottom end, crucial during travel through mountain passes and hard turns. Toss in a clutch that is fairly easy to modulate and has a low release point - along with a default rear wheel drive setup -and you have an ideal mix between diesel sipping and outright power.
A third answer is turbocharging. Because the burned gases are expanded further in a diesel engine cylinder, the result is that the exhaust gases coming out of the cylinders are cooler. And since turbos require cool exhaust gases to make its propellers spin (and deliver a charge of cool air to the engine block), its very nature makes it the ideal choice for diesel engines. Also, the advent of variable geometry turbocharging (so-called because the turbine housing's blades are positioned at double-digit degree increments, thus changing the surface they present to the exhaust gases) minimizes turbo lag (rotational inertia experienced by the turbo blades when little or no exhaust gas passes through the turbo), kicks in at lower engine speeds and provides faster velocity.
Then you have CRDi. This means that all of the diesel fuel injectors are supplied by a common fuel rail (more of a pressure accumulator) where the fuel is stored at high pressure. This accumulator supplies multiple fuel injectors with high pressure fuel, simplifying the purpose of the high pressure pump in that it only has to maintain a commanded pressure at a target. The higher pressure that the common rail technology makes available provides better fuel atomization, reducing engine noise (which can affect acceleration) and emissions and requiring no warmup time.
All of these factors came together in a recent event held by Universal Motors Corporation (UMC, official distributor of Nissan diesel utility vehicles) and participated by motoring scribes to demonstrate the sheer tarmac pace and power-to-the-ground delivery of the Navara. The event, billed as the Navara Speed Run, had scribes launch the Navara (in both a/t and m/t variants) from rest to 100 kph acceleration run and stop the pickup from 100 kph to zero in the shortest distance possible. Logged faithfully by Speedlab's Ferman Lao, the 0-100 times ranged from 11.6-12.2 seconds (for the former) and 45-47 feet (for the latter) - statistics close to those posted by PCs. For the record, this writer posted a 0-100 kph time of 12.2 seconds and a braking distance of 46 feet. On the other hand, fellow autoindustriya.com writer Inigo Roces logged a 11.7 second 0-100 kph time and a 100-0 kph braking distance of 48 feet. "This event changes what you expect from a pickup truck and changes what you want from a pickup truck. The results speak for themselves, and if you're looking for a pickup you will demand nothing less than a sport utility pickup like the Nissan Frontier Navara," said UMC (marketing group) executive vice president Beth Lee.
With what's under the hood and how all that wicked power and torque is delivered to the wheels, the Navara can be considered as a pickup with the soul of a sportscar or a passenger car.