Bajaj Wave DTS-i

Bajaj RE 60 – 200cc 4 wheeler

The Auto Expo is yet to officially begin, but Bajaj has already fired a significant salvo. They have just unveiled the Bajaj RE60, their small, eco friendly vehicle.

The Bajaj RE60 certainly looks striking, as small cars go. The front fender looks a little overdone, but when painted in the same colour as the body, it blends in better. At first glance, it is compact, but the interior is surprisingly roomy, much like the Tata Nano .

The car is fuel injected and uses twin spark ignition, and it is water cooled. The company claims a real world fuel mileage of 35 kpl, with a carbon emission of 60 grams per kilometre. which also reflects in the name Bajaj RE’60’. The body weighs 400 kg and the car is powered by a 4-stroke engine. There is also a fuel injected CNG variant available.

No electric options will be available.

The compact RE60 has a turning radius of 3.5 metres. On the inside are moulded seats, 400 litre boot space, digital instruments. And to keep the windscreen clean is a single windscreen wiper.

The Bajaj RE60 will be available in two versions – commercial and deluxe. The Bajaj RE60 comes powered by a 200 cc petrol engine that is rear mounted. The engine is a four valve, fuel injected, liquid cooled affair with an all new transmission linked to it. The car can make 20 bhp and will also be available in LPG and CNG variants.

Bajaj has no diesel variant planned for the car as the diesel engine will be too heavy.

The car will be ready for production in a few months time, and will be manufactured in Aurangabad at the three-wheeler plant whose capacity will be expanded.

Pricing details are yet to be revealed.

Rajiv Bajaj said that the company wanted to start the new year with a bang, following on from the success of the last two years. Beginning with the Chetak, the cheapest scooter in the country, the company has moved on to making some of the most expensive motorcyles sold in India, and it is now the most profitable automotive company in the world.

With this being the background, it is perhaps surprising that Bajaj has opted to go the four-wheeled way – Rajiv Bajaj explained thiz by quoting Jack Trout. who said ‘leaders should do more, it is only right’. The task Bajaj presented itself with was to make best use of the resources already available to them, rather than to try and reinvent the wheel. The company emphasised that no government subsidies were needed in the making of the Bajaj RE60.

It is not electric, as it was at pains to emphasise, because the energy involved in producing an electric vehicle tends to offset the zero emissions at the tailpipe. In fact, Bajaj’s whole presentation at the unveiling centred heavily around the ill effects of pollution, citing mortality rates related to air pollution and figures showing the extent to which internal combustion engines contribute to the degradation of the environment.

The production process is also green, claims Rajiv Bajaj, and the company has saved almost Rs 350 crore by utilising the existing facilities. The platform has been totally developed by the company from scratch. He also revealed that Renault and Nissan have not seen the final product, only a virtual picture, and if they do decide to wash their hands off the idea, it is fine with Bajaj.

However, only after the Expo will there be a clearer picture of any alliance or agreements.

Bajaj is an anti car company, Rajiv Bajaj went on to say, in the same way that 7up is an anti-Cola company. This is why they are insist on calling themselves a four wheeler company, and the Bajaj RE60 a four wheeler, as opposed to a low cost car, as it was first discussed with Renault/Nissan.

The RE name has become synonymous with their three wheelers, hence the continuation of the brand name. The objective was to keep things simple and centred with this four-wheeler, they said, and the aim is for it to become an affordable, viable alternative to available personal transportation. It is not intended to replace the three wheeler, and there is no commercial, goods carrying, use intended, although it will be used as a taxi.

It is fully ready to be qualified as a quadricycle in Europe.

Ps. Origin of DTS-I

The ‘Twin Spark’

Alfa Romeo Twin Spark (TS) technology was used first time in Alfa Romeo Grand Prix car in 1914. In the early 1960s it was used in their race cars (GTA. TZ ) to enable it to achieve a higher power output from its engines. And in the early and middle 1980s, Alfa Romeo incorporated this technology into their road cars to enhance their performance and to comply with stricter emission controls.Twin Spark name usually refers to the dual ignition engines installed in Alfa Romeo cars.

The 8 valve engine was fitted initially to the Alfa Romeo 75 but also the Alfa Romeo 164 and Alfa Romeo 155. The 16 valve engines appeared in the Alfa Romeo 145. Alfa Romeo 146. Alfa Romeo 155. Alfa Romeo 156.

Alfa Romeo 147. Alfa Romeo 166. Alfa Romeo GTV Spider and even Alfa Romeo GT models.

The TS series engines are all ‘4 cylinder inline’ with twin cam (DOHC ) shafts. The original 8 valve engine featured a light alloy (Si enhanced alu alloy) block + head, wet cooled iron cylinder liners and the camshafts were driven by double row timing chains (long and short). Similar design to the earlier and famous Alfa Romeo DOHC engines, but with narrower valve angle on this model.

The later 16 valve engines had a heavier cast iron block engine, with an alloy head, and the camshafts were belt driven. The Twin Spark name comes from the fact that there are two spark plugs per cylinder. The block was Fiat sourced. It was cast iron for its higher beam strength, less complexity and hence lower production costs.

When new, these engines were notable for their high efficiency as demonstrated by the BMEP (brake mean effective pressures) exerted upon the piston crowns.

The two sparks on the 8V Alfa Twin Spark engines do not fire at exactly the same time (true at least of the 75 which uses traditional ignition coils with king leads and distributors). This was deliberate to avoid the most powerful part of the flame fronts meeting at the centre (weakest part) of the piston.

As there are 2 symmetrically placed sparks plugs, the flame front must travel less distance which allows less ignition advance to be used and it is accepted ignition timing can be closer to optimal than a single spark plug would allow. Also, leaner mixtures can also be tolerated for better fuel economy. The 8V engine also has 8 identical spark plugs.

There is no room for a centrally positioned spark plug due to the 2 valve design which uses a 44mm diameter inlet valve on the 2.0 engine.

Bajaj Wave DTS-i

On 16V engines there is room for a spark plug in the centre of the cylinder as in all 4-valve configuration engines, but also a second smaller plug (off to the side on the axis) is installed. Both of the plugs fire at exactly the same time on compression and exhaust stroke, due to the way in which the coils are paired (14 and 23).

This production economy allows the use of 4 coils, instead of eight, which would normally be required to fire eight plugs, and is common practice called wasted spark system. (used also in Ford EDIS system as well as in some Alfa Romeo V6 engines 3 coils for the 6 cylinders). The main reason for the wasted spark system is cost. As both plugs are connected to the same coil the spark one of them operates with reversed polarity and requires decreased breakdown voltage.

On the later CF3 (2001 on Euro 3 emissions standard) 16v TS the four coils fire the same cylinder spark plugs (so not 1 and 4 and 2 and 3 as pairs but coil #1 fires the big and small plug of cylinder 1, and so on). The TS 16V engines, 1.6, 1.8 and 2.0, all use a 10 mm diameter and a 14 mm diameter long life platinum electrode spark plug per cylinder. The spark plugs have a replacement interval of 100,000 kilometres (62,000 mi).

The operation of the Twin spark engine has been subject to much debate but this is the general theory of operation, as described by Auto Italia magazine.

16 valve Twin Spark with older cover.

The engines also incorporate two other devices to enhance the performance under operation, the Camshaft Phase Variator and the Variable Intake Length Control (or Modular Inlet Manifold in Alfaspeak) on the later (plastic cam cover) 1.8 and 2.0 litre versions. Where both these variable systems are deployed they are controlled in tandem by the Bosch Motronic Engine Management ECU in response to rpm, load, and throttle position.

According Fiat Auto S.p.A DTE electronic service documentation for the Alfa Romeo 156 Twinspark (1.8/2.0). To optimise the quantity of air drawn into the engine the control unit checks: inlet timing on two angle positions (and) geometry of inlet ducts at two lengths (only 1.8/2.0 TS). At maximum torque speed the control unit sets the open phase: cam advanced by 25-, inlet casing long ducts (Only 1.8/2.0 TS).

At the maximum power speed the control unit sets the closed phase: cam in normal position, inlet box short ducts. At idle speed the control unit sets the closed phase: cam in normal position and inlet box short ducts. In the other engine operating conditions, the control unit selects the most suitable configuration to optimise performance – consumption – emissions.

During overrunning, the inlet ducts of the box are always short.

The advancing of the inlet camshaft by 25 crankshaft degrees (or 12.5 camshaft degrees) opens and closes the intake valves earlier in the inlet cycle. This allows the filling of the cylinders with air/fuel mix to begin earlier. and by closing sooner trap more of the fuel/air mix for the compression phase of the combustion process.

On 1.8 and 2.0 16V Twinsparks the longer inlet ducts deployed in conjunction with the advanced inlet cam, are of a tuned length that assists cylinder filling by harnessing the harmonic pressure wave present in the lnlet duct. In this way the dynamic effective compression ratio is increased which produces more torque at the given engine speed.

As the intake valve is also opened earlier in relation to the exhaust valves, the valve overlap (the period both inlet and exhaust valves are simultaneously open) is also increased at this mode. This promotes the scavenging effect of the exiting exhaust which causes a partial vacuum in the cylinder to further assist in filling the cylinder with a fresh charge.

As with similar inlet cam phasing systems like BMW VANOS the phasing is returned to the retarded state at higher rpm to improve power and effiency as inlet gas dynamics change with rpm. The short inlet ducts being tuned to the higher frequency and thus shorter inlet duct pressure wave.

On 8V engines the valve overlap and intake open duration are quite big. These engines hardly idle with the variator at On position so on these models it had the meaning also to enhance lower speed operation. On the newer 16V engines the camshaft variator is used to enhance the performance/emissions but also might be the source to the common ‘diesel noise’ problem often seen on high mileage used models which used the earlier internals of the variator.

The same variator system is also used in many Fiat /Lancia engines like one used in Lancia Kappa 5-cylinder engine, some Fiat Bravo /Fiat Marea engines, Fiat Barchetta. Fiat Coupe. Fiat Stilo etc. models.

Bajaj Wave DTS-i
Bajaj Wave DTS-i

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