Otnas Harimau – In Between Utility and Motorsports – A PREVIEW
Introduction
In the FUTURA project, Otnas also planned to enter the market that is highly popular in Indonesia; the AUV. Asian Utility Vehicle (or in short AUV) is a type of car that is a blend of MPV and SUV. They are mostly found on developing countries in Southeast Asia. However, it is known that they were exported to countries outside Asia later. They are mostly MPVs that can haul 7 to 10 people and is built on a small truck platform. The top seller is the Toyota Kijang and Otnas wanted to build something that competes the following car. Below are the main points that the Otnas Harimau needs to fulfil.
First, they need a small economical engine that would be powerful enough to climb hills whilst having atleast seven people in the car.
Second, AUVs needs to be simple, cheap, and easy to maintain. Reusing parts from the first gen Otnas Kucing is ideal which means there’ll be more parts to use.
Third, it needs to be reliable. The reliability of the AUV needs to be high since most of the roads back in the days are unpaved, dark, and in the middle of a rainforest. You don’t want to have your car to break down in the forest midnight.
However, Otnas is no longer seen as a startup automotive company from a third-world country. Otnas is known to offer cutting edge technology and engineering and since the Otnas Tamtam is a premium compact sedan, the Otnas Harimau needs to hold a prestige despite being a very affordable option for Otnas buyers. Otnas then demands the Harimau to fulfil these criterias;
First, it needs to enter a racing league. This means that the suspension, chassis, and engine setup need to be capable of hardcore driving and it is expected that the car will be a joy to drive even the base models.
Second, it needs to introduce people a new kind of technology – that is turbocharging in AUVs, aluminium panels at certain areas, and 4x4.
Third, it needs to hold a legendary and future classic status.
Otnas Harimau Dakar Esprit 4x4 1.8 [1988]
Otnas believes that if you want to win, you need to develop the racecar first then the lesser models. That sent the Otnas Tamtam winning trophies at the racetrack. The Otnas Harimau is also made in the same way – and it’s quite crazy to think that a car that competes with a Toyota Kijang has a hardcore rally homologation variant.
Unlike most AUVs, the Otnas Harimau is built upon a spaceframe chassis to ensure rigidity and lightness. The ladder frame construction is rugged, but Otnas wants lightness, and great handling so they chose spaceframe instead.
At the front, the car has MacPherson struts so it’s cheaper to maintain the front suspension than its competitors that had to have double-wishbone suspension due to engineering limitations.
At the back, it has live axle with coil springs and four longitudinal bars to stabilize its movements.
The engine is placed near the middle of the car, so the weight distribution is balanced. For the Dakar Esprit 4x4 1.8 model, it has a weight distribution of 53/47.
Some panels such as the roof, hood, and doors are made from alumium alloy to reduce weight and higher corrosion resistance.
Otnas is aware of the lack of safety the AUVs have. So, they decided to equip the Harimau with standard 80s equipment such as pretensioning seatbelts, crumple zones, safety glass, and inertia switch that shuts off the fuel pump in an event of a crash.
The total weight of the car is 1441 kg.
It was planned that the FUTURA 2.5 litre Inline 5 turbodiesel engine to power the Otnas Harimau Dakar Esprit 4x4. However, it’ll be too expensive for many people to buy so they decided to turbocharge the Otnas Kucing’s Purring Cat 1 engine instead.
The engine received different cams to produce low end power better. The cylinder head was also received different valve springs, valves, and is re-machined.
The engine block is also made out of stronger cast iron to handle 2 bar of boost pressure as stock and so are the pistons, connecting rods, and crankshaft are also reinforced to handle 800 Nm of torque.
The fuel system now is managed by a Bosch KE-Jetronic system which ensures more precise fuel delivery that results in bigger power and better fuel efficiency.
For the intake, it has individual throttle bodies with a plenum. The variable geometry turbo runs at 0.8 bar of boost and would fully spool at 2300 rpm. By the turbocharger being this responsive, the driver would not experience sudden boost spike as they are driving which means better drivability. This also gives fuel efficiency advantages since the turbo already spools at city driving conditions.
The engine produces 231hp at 5600rpm and 342Nm of torque at 2300-4000rpm. The power is sent to all four wheels via a 4x4 drivetrain and locking differentials.
To be revealed fully soon as the car is finished…