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ZF unveils new 8-speed automatic gearbox

May 3, 2007 at 10:34 pm By Paul Tan Filed Under Cars, International News, Technology

ZF 8-Speed Auto

ZF, a company whose gearboxes are in many of our cars including that sweet new fast shifting quick locking 6-speed auto in modern BMWs has unveiled a new 8-speed automatic gearbox and presented it at the 28th International Vienna Motor Symposium.

Though some of you may think ZF is yet another automakers who wants to lead in the cog race, which is currently led by Lexus with their 8-speed auto, but ZF says number of gears was not a priority when designing this unit.

“Our main development target was to find a transmission concept which allows for significant additional fuel consumption reduction and thus offers tangible added value to our customers and drivers without making any compromises in terms of performance”, explains Dr. Michael Paul, ZF Executive Vice President, Technology and Group Executive of the Car Driveline Technology division. It just so happened that to achieve those targets, 8 gears was needed.

The new gearbox can also handle larger input torque with the same weight as compared to the previous model, the second generation 6-speed that’s found in the 335i. It was also designed to be modular, which means it can be used in all-wheel drive systems without much modification. The torque converter can be replaced by new clutches or could be omitted completely when an integrated starting clutch is used.

The new ZF 8-speed automatic transmission will be used in the F01/F02 2009 BMW 7-Series in the flagship V12 model, and possibly the Rolls Royce RR4 later.

ZF 8-Speed Comparison Chart

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New 122hp turbocharged 1.4 liter and 7-speed DSG from Volkswagen

April 28, 2007 at 10:25 am By Paul Tan Filed Under Cars, International News, Technology, Volkswagen

Volkswagen has revealed yet another new engine at the 2007 Vienna International Motor Symposium. This new unit is a 1.4 litre turbocharged unit making 122 horsepower and 200Nm of torque from as low as 1,500rpm! This unit is not to be confused with Volkswagen’s 1.4 litre TSI engines which are available in both 140hp and 170hp forms, as this new 122hp engine only uses a turbocharger without the addition of a supercharger as with the TSI engines.

Volkswagen also demonstrated it’s new DQ200 7-speed DSG gearbox, which adds one more gear ratio to it’s existing DG250 six-speed DSG units. The 7-speed DQ200 handles torque figures of up to 200Nm, making it suitable for low displacement applications like this new 1.4 litre TFSI. It won’t find it’s way into performance models until can sustain more torque.

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Homogeneous Charge Compression Ignition

April 17, 2007 at 6:45 am By Paul Tan Filed Under Cars, Technology

Something new to the internal combustion engine world is HCCI — Homogeneous Charge Compression Ignition, yet to be seen in any production vehicle by any manufacturer. A few car manufacturers have been experimenting with this, among them Honda who wants to introduce HCCI with it’s IMA Hybrid system.

What exactly is HCCI? Basically. Homogeneous Charge Compression Ignition ignites an air fuel mixture without any flame, plus a large area can be ignited simultaneously, much different from a conventional spark flame burn where the mixture burns first from the area around the initial spark and proceeds to the rest of the combustion chamber. This is somewhat similiar to a diesel engine’s self-ignition. Diesel self-ignition is called SCCI, or Stratified Charge Compression Ignition.

Engineers have predicted a potential 20 to 30% boost in engine efficiency over conventional gasoline combustion engines, and an improved thermal efficiency of about 40% to 50%. Honda calls it’s HCCI technology Activated Radical Combustion, and have been experimenting with two-stroke motorcycle engines. A 4-cylinder HCCI engine for cars is also in development, though currently progress has enabled HCCI on the lower RPM ranges of about 0 to 4,000rpm only. However, during normal non-spirited driving the rev rarely goes above 4,000rpm anyway.

A key problem is how to measure ignition timing accurately. This is not a problem in diesel self-ignition, as hot air is compressed and ignition starts when fuel is injected into the combustion chamber filled with the hot air. In a HCCI gasoline engine, the air-fuel mix is already in the combustion chamber before the piston starts compressing it. According to Lawrence Livermore Laboratory, some ways to ovecome this would be to recirculate exhaust gases into the fuel/air mix to quickly raise its temperature, or to add dimethyl ether to the fuel/air mixture to improve combustion.

Another idea would be to compress the air-fuel mixture to the point where it is just about to ignite, then injecting a second dosage of low octane fuel that combusts easily. That fuel would detonate, increasing temperature and detonating the rest of the air fuel mixture. The ignition timing could start from whenever the engine injects that second dosage of fuel.

Related Sites:
HCCI engines could bring breakthrough fuel efficiency

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Honda files Advanced VTEC patent

April 17, 2007 at 3:34 am By Paul Tan Filed Under Cars, Honda, Technology

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Through a patent filing filed by Honda Motor Co Japan, we now have a preview on how Honda’s next generation AVTEC system will work. Basically, AVTEC enhances the features of VTEC and i-VTEC by providing a fully variable valve timing and lift control system. i-VTEC previously provides continuous valve timing, but not valve lift. The only fully variable valve timing and lift system on the market currently is BMW’s Valvetronic, which also removes the need for a throttle butterfly. Every other system as of today has fully variable valve timing, but valve lift is only switchable between two fixed profiles.

So how does AVTEC work? The full text of the patent including drawings is available after the jump, but I will attempt to summarise it from whatever understanding I have. Honda’s new AVTEC system basically uses a small drum that surrounds the intake camshaft. This drum is connected to a rocker shaft. When this drum turns, it alters the position of the rocket shaft, thus affecting valve timing and valve lift.

Read the full patent together with diagrams after the jump.
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New BMW 204hp, 400Nm twin turbodiesel inline-4

March 26, 2007 at 2:41 am By Paul Tan Filed Under BMW, Cars, International News, Technology

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I’ve tried out BMW’s 2.0 litre inline-4 turbodiesel engine used in the BMW 320d and have had good experiences with it, despite the noticable turbo lag. BMW has upped the ante once again with it’s second twin-turbodiesel engine after the 3.0 litre twin turbodiesel used in the 535d and 335d.

The previous 3.0 litre twinturbo was a record in production car turbodiesel application, making 91 horsepower per litre and ridiculously huge amounts of torque. This new 2.0 litre twinturbo inline-4 surpasses that, making roughly 100hp per litre – it’s power figures are 204 horsepower and 400Nm of torque! For comparison’s sake, it’s single-turbo sibling in the 320d I tested makes 163hp at 4,000rpm and 340Nm of torque between 2,000rpm to 2,750rpm.

The 400Nm figure is as much torque as what the new M3′s 4.0 litre V8 makes. All 400 Newton meters kick in at a low 2,000rpm, but that’s not the best part. Half of that, which is 200 Newton meters, is available from just 1,200rpm! That’s only slightly above idle!

The twin turbocharging system is a sequential one, instead of parallel like the 335i‘s N54 Bi-Turbo. In this sequential system, a smaller turbo takes care of the low revs while a bigger one boosts power towards the redline. Despite all that power, fuel consumption is just 4.9 litres of diesel per 100 km.

Opel currently unofficially holds the record of the highest horsepower per displacement for a turbodiesel. It’s OPC division developed 1.9 litre ECOTEC CDTI twin-turbo makes 112hp per litre, for a total of 212hp and 400Nm of torque, which kicks in lower at only 1,400rpm. However, since it’s announcement in early 2004, it has not been used in any production car yet.

One more photo and a torque curve graph after the jump.
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The New BMW M3 V8 Engine Specifications

March 23, 2007 at 4:07 am By Paul Tan Filed Under BMW, Cars, Technology

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BMW’s new and upcoming E92 BMW M3 marks the shift to V8 power after 15 years of six-cylinder power. The E46 M3′s 3.2 litre straight-six was a legend, and is still being used by the current Z4 M Coupe and Roadster. The engine clinched the Engine of the Year award multiple times. It made 343hp in it’s latest edition. But in it’s main application in the M3, it’s time for it to bow and leave the stage and make way for it’s successor, the new BMW M V8 engine.

This new engine displaces 3,999cc and makes 420hp at 8,300rpm, It is a screamer, revving all the way to a redline of 8,400rpm. Torque peaks at 3,900rpm with 400 newton meters, with 340Nm available from as low as 2,000rpm. The new 4.0 litre V8 is also amazingly lighter than the 3.2 litre inline-6 it replaces, weighing in at a mere 202kg, 15kg lighter than the inline-6, despite an additional 2 cylinders and all the extra valvetrain parts for a 90 degree V-design.

The valvetrain uses double-VANOS variable camshaft control now with a new low pressure design, and intake is via eight individual throttle butterflies for the best in engine response time. And of course, in line with BMW’s new Efficient Dynamics plan, it has Brake Energy Regeneration, usually not found in non-hybrid cars.

While it all looks impressive, I was expecting more torque than this, however it’s very commendable that BMW managed to make most of the torque available from a relatively low RPM, despite the very wide rev range that peaks at 8,300rpm. I wonder why BMW decided not to fit the engine with direct injection.

Somehow I feel the M3 is not going to be as exciting as I thought it would be. Sure, it’s an M3, and I would love the chance to drive it if somehow circumstances let me. But just not that much. I reckon a 335i M Sport tuned up to the regions of 370hp and ALOT more torque than the 400Nm this V8 makes as well sounds like the better deal. Just give it a Hartge LSD for it to keep up with the M3 with that wonderful M differential around the corners. But of course that’s all aftermarket and in the end, it still wouldn’t be an M3. It would just be a tricked out 335i. And later, a tricked out M3 will come along and smoke it.

Please head on to the BMW M3 V8 Engine Photo gallery for a collection of high resolution photos as well as an image showing the torque curve of this new engine.

A full technical press release is after the jump.

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[Read more...]

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Siemens Electronic Wedge Brake (EWB)

March 15, 2007 at 4:00 am By Paul Tan Filed Under Cars, Technology, Videos

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So you’ve got the drum brake, then the disc brake, then the disc brake with multiple calipers. Then you improve that further with slots, cross-drill holes and make the whole disc ventilated. Even brake by wire has been introduced. What next, something totally different?

Introducing the Electronic Wedge Brake (EWB), a technology by Siemens VDO, based on a concept from aerospace engineering. The Electronic Wedge Brake completely bypasses any hydraulic system, instead it is powered by a simple 12-volt power system that already exists in the car. The system also has a faster reaction time, it works about a third quicker than conventional brakes, only requiring 100ms to reach full braking power compared to a hydraulic brake’s 170ms.

Basically, a brake pad connected to a wedge is pressed between the rod and the disc through the use of electric motors. The electric motors turn and push the pad onto the disc. The use of a wedge means braking power is multiplied with minimal energy expenditure (about one tenth of hydraulic brakes), through the principle of self-energization. The faster you are going, the stronger the brake force is going to be. The lack of a physical connection between brake pedal and brakes also makes this a brake by wire system by default. Sensors measuring wheel speed about a hundred times a second can adjust brake forces and wedge position to a high degree of accuracy, somewhat like ABS and stability control rolled into one.

Test results have been amazing so far. An Audi A6 fitted with the Electronic Wedge Brake system was put to the test comparing against another A6 with conventional brakes. The braking distance required from 100 km/h to 0 km/h was reduced by half in the EWB-equipped A6!

However, all brake by wire systems make you wonder what would happen if somehow power supply were to be disrupted. Something simple like the battery going flat because the engine’s alternator malfunctioned. To take care of this, the EWB is specified to be connected to two power supplies, a main one and a backup one with a secondary battery.

This is a good advancement in braking technology. The first car with EWD is expected to debut by 2010, and it will most likely be a German marque. Might be Audi since they were testing with Audis. More photos and a video after the jump.
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Lotus Integrated Exhaust Manifold

March 14, 2007 at 2:45 am By Paul Tan Filed Under Cars, International News, Lotus, Technology

small_lotus_logo.jpgLotus Engineering displayed their Integrated Exhaust Manifold technology at the 2007 Geneva International Motor Show. Basically, it is an exhaust manifold integrated into the cylinder head. A demonstration of this was shown as a cylinder head design for a small 3-cylinder engine, which I would say would benefit much from this technology. Integrating the exhaust manifold into the cylinder head brings numerous benefits which I will outline below.

An integrated exhaust manifold reduces parts count, which reduces costs throughout the development cycle. Other areas where this will reduce costs include the inventory, assembly and aftermarket parts supply areas. Less parts, less to stock.

Through the use of a cooling jacket design, heat is retained in the engine (which is cooled via the radiator system) rather than letting it radiate into the engine bay. This improves the performance of the air conditioning system, thus reducing it’s power consumption. A cooler engine bay also means cooler air into the air intake, which boosts performance. The engine also warms up more quickly. Coolant can also cool the engine more evenly, reducing engine block stress.

Engine durability improves, as thermal stresses usually occur at points where different materials meet. In an engine with a conventional exhaust system design, an aluminium cylinder head meeting a cast iron exhaust causes thermal stress.

The integrated exhaust manifold also allows the catalytic converter to be positioned very near the exhaust output, thus reducing the amount of exhaust heat lost in travelling from the cylinder to the catalyst. This improves catalyst performance, thus reducing emissions to an ultra-low level without incurring higher costs.

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Kia Rio Hybrid introduced at Geneva 2007

March 7, 2007 at 6:24 pm By Paul Tan Filed Under Cars, International News, Kia, Koreans, Technology

Kia Rio Hybrid 1

Proton is not the only one with a sedan modified to go the hybrid way – the Koreans have their Kia Rio Hybrid for display at he 77th Salon de lAutomobiles in Geneva as well. This Kia Rio Sedan has it’s 1.4 litre CVVT petrol engine mated to a 12 kilowatt, 95Nm electric motor, and like the GEN2 EVE, uses a CVT gearbox, a first in any Kia car.

The CVVT engine makes about 90 horsepower and 120Nm of torque, and is hooked up to the electric motor which is placed between the flywheel and the gearbox. This electric motor ‘assists the petrol engine during starting, accelerating and hill-climbing. The electric motor switches off at cruising speeds, and also has ‘regenerative braking to store energy and re-charge its Ni-MH 144 volt power pack. There’s also a start-stop system for shutting off the petrol engine when not needed and restarting it automatically.

Zero to 100 km/h takes 12.2 seconds, top speed is 180km/h, and compared to a standard Kia Rio, air pollutants are reduced by 37% (down to 126g/km) and fuel efficiency is improved by 44% (now rated at 4.4 litres per 100km). To help with the fuel consumption, the body of this Kia Rio Sedan has also been changed slightly, saving about 220kg of weight through the use of an aluminium bonnet, boot lid and front seat frames, plus lightweight road wheels, low-friction tyres and an electric power steering.

Three more photos after the jump.
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DaimlerChrysler and BMW in joint hybrid drive module development

March 5, 2007 at 3:56 am By Paul Tan Filed Under BMW, Cars, International News, Mercedes Benz, Technology

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Hybrid 7-series within the next 3 years?

DaimlerChrysler and BMW will be extending their hybrid drive system collaboration, developing a unique hybrid drive module for rear wheel drive cars, with commercialization of the module expected within the next three years. This joint venture is in the interest of saving costs in R&D as well as manufacturing.

Lexus has gone the mild hybrid way for quite some time now, with offerings like the Lexus RX450h luxury SUV, Lexus GS450h mid-sized luxury saloon and the flagship Lexus LS600h. Now when I say mild hybrid, that refers to hybrid powertrains that focus more on helping acceleration, and save a bit of fuel especially in stop and go traffic. Large displacement engines usually prove to be guzzlers in stop and go situations. It is not meant to focus on massive fuel savings like the Toyota Prius and Honda Insight.

Now most of you who have been observing hybrid/electric car specs should have noticed most of them have crazy acceleration times thanks to the electric motor’s perpetually maxed out torque at all RPMs. Imagine a BMW 3-series coupled with a hybrid drivetrain system accelerating out of a corner, now that has got me licking my lips, though this technology will most likely first be used on both Mercedes Benz and BMW’s larger vehicles like the 7-Series (shown above) and S-class, as well as SUVs, as the relatively larger displacement engines in these two classes of vehicles would benefit the most from the fuel savings of an electric motor in stop and go traffic.

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