Archive for Technology

UK-based Antonov Automotive Technologies is advocating the use of a dual-speed supercharger (which they are already producing and continuously improving) for the current trend of downsizing displacement and force inducting engines in efforts to improve fuel economy and emissions.

“Car makers are increasingly looking at superchargers to enhance the performance of small engines. Unlike turbochargers there are no heat issues to manage, and the study of exhaust gases can then be assigned to energy recovery systems,” says Antonov operations director Chris Baylis.

According to Antonov, a dual-speed supercharger which can run faster at low engine RPMs for that instant “kick” and run slower at high engine RPMs to extend the boosted torque curve across the rev range can be much cheaper than complex combinations of a supercharger and turbocharger like the Volkswagen 1.4 liter TSI’s twin-charger.

Prodrive is currently developing an innovative system called Active Toe Control that may eliminate the need for complicated multi-link rear suspension setups.

Active Toe Control works on the rear axle of a front wheel drive car to adjust the toe angle depending on the speed of the vehicle. Toe angle is typically set between a compromise of giving a vehicle agile handling at lower speeds (toe-out on the rear axle) or making it more stable and predictable at high speed (toe-in). Active Toe Control eliminates this compromise, ensuring optimum toe angle at all times.

“Typically most drivers stay well within 60-70 per cent of their car’s capabilities. This means vehicle manufacturers are increasingly focusing on making their cars feel more sporty in this region, without necessarily increasing their outright performance,” says Matt Taylor, Prodrive chief dynamics specialist.

According to Taylor, handling characteristics are increasingly becoming attributes of vehicle brands. A German car is expected to have its yaw rate and lateral acceleration build at the same time, so you feel as if the rear wheels are following the front wheels, with the car turning around the rear axle.

A typical French front wheel drive car however, is expected to have its lateral acceleration lag behind the yaw rate gain where the suspension flexibility allows the rear wheels to move sideways before ‘pushing’ the rear of the car.

“This gives the driver the sensation that the car is momentarily turning on the spot around its centre of gravity, as the nose tucks in and the back kicks out, giving an agile feeling. Neither approach is right or wrong, it’s a matter of preference. Vehicle manufacturers really want ways to reduce the production cost of their cars. Replacing simple twist beam axles with more expensive multi-link systems goes against the grain, but as they all strive for class leading handling, it is direction they are being forced to take. With Active Toe Control you have the added benefit of refining the handling simply by changing the control algorithms on the production line or at the dealer, to give the characteristics favoured by whichever market the car is to be sold,” adds Taylor.

Active Toe Control is still conceptual at this time, and Prodrive is looking for a hardware partner to take the project to a working prototype.

Related Links:
What is Toe Angle? (Wikipedia)

Mitsubishi Motors has published a list of what they claim are technical innovations in the new Mitsubishi Lancer Evolution X. The list does look very fancy indeed, and stuff like ETACs will lend the Lancer Evolution X a much needed more upmarket feel - the Evo 9 did not really feel its price.

• No Reverse Gear - The 5-speed manual does not have a reverse gear, instead it uses a combination of gears 1 and 3 with an idler gear on a separate shaft to reverse the direction of rotation.
• Spoilers In The Wheel Arch - A miniscule spoiler lip protects wheel houses from swirling wind, this improves aerodynamics.
• Energy Saving Glass - This reduces solar heat transmission by 66 to 100%, and cuts out UV light so that the air conditioning system does not have to work too hard.
• Stainless Steel Manifold - the insides of the exhaust manifold is smoother.
• ETACs - The Mitsubishi Electronic Total Automobile Control system lets the driver personalise his car. For example, he or she can decide how long the interior light stays on after door closure, or just disable the feature. The wing mirrors can also be set to automatically fold when the door is closed and ignition switched off.
• Acoustic Engineering - Lightweight acoustic and vibration dampening materials including foam filling for pillars for good NVH while minimizing weight increase.
• Adaptive Front Lighting - HID lamps light up the way ahead but additional beams light up to illuminate corners.
• Vents - vents are placed around the car like the ones on the hood and behind the front wheels to release heat, and a central air intake for cool air.
• F1 Piston Technology - The 4B11T uses Mahle full floating pistons which are based on F1 technology. The pistons are made of a very hard and strong alloy. The 4B11T is about 12kg lighter than the outgoing 4G63T.

FM transmitters have become a rather popular car accessory these days, as most car manufacturers have yet to settle on MP3-capable CD players as a standard feature. Burning a limited amount of tracks to Audio CDs can be a pain, so many are turning to playing songs from their portable MP3 players. Because many cars also lack aux input for audio, you have to use something called an FM transmitter to interface between the MP3 player and the head unit.

The FM transmitter basically takes your MP3 player’s audio output and transmits it on an FM frequency that you specify. Then you tune your head unit in to the frequency and you get to listen to whatever songs the MP3 player is playing. Some FM transmitters are standalone, and they read songs from a memory card like an SD card. Some are rather premium, like the iTrip for the iPod.

The Nokia N78 succeeds the N73 Music Edition, and at first sight you might assume it is just another candybar phone that’s aimed at those who want an MP3 player in their mobile phone. But one unique feature is that the phone has a built-in FM transmitter. You just select the FM frequency that you want to transmit your music on and activate the transmitter. Then just tuned into the selected frequency on your car head unit. The phone transmits RDS text as well - “Nokia”, but it would be better if the song title could be transmitted as well.

VIDEO: Nokia N78

Other features of the N78 include A-GPS with Nokia Maps 2.0, Wifi, 3.5G HSDPA connectivity, support for standard 3.5mm headphone plugs, a 3.2 megapixel camera, and Nokia Internet Radio. I’m thinking with an unlimited data plan, you could stream the internet radio to your car audio. That should give those who are bored of our local radio channels some variety.

Of course, hardcore audiophiles will never consider something like this as there’s just so much loss of quality incurred through all the multiple layers of mediums - even including air - that the audio has to go to before it reaches your speakers. Track-by-track CD audio is the choice for quality.

The new Nokia N78 will ship in Q2 2008. More photos of the Nokia N78 after the jump.

Click here to read the rest of Nokia N78 with FM Transmitter

UPDATE: Apparently this is an innovative use of a single clutch combined with the 7G-Tronic automated transmission (replacing the torque converter for startups), and not a dual clutch transmission. The MCT (Multi-Clutch Technology) acronym refers to a planetary (automatic) transmission’s multiple clutches and bands for each gear.

Mercedes-AMG GmbH finally gets more cogs than their usual 5-speed automatic with their new Mercedes-Benz SL 63 AMG. The 7-speed AMG SPEEDSHIFT MCT (Multi-Clutch Technology) uses a clutch to swap gears and moves off with a wet start-up clutch instead of a torque converter.

The AMG SPEEDSHIFT MCT 7-speed gearbox has 4 drive modes - C (Comfort), S (Sport), S+ (Sport plus), and M (Manual). Throttle response and shifts in comfort mode are “softer”, while in S mode shifts are faster and the clutches bite quicker. Shifts are approximately 20% faster than in Comfort mode, and for a further 20% speed improvement you can use S+. Using M mode, a further 10% is cut down for a total of 50% over the C mode - shifts only take 100 milliseconds in the M mode.

Downshifts in S, S+ and M modes use precise double-declutching and can downshift multiple gears, straight from 7th down to 3rd for example. This gives the drive a more sporty feel as the engine and exhaust sound great during double declutching, and also serves to minimize load-change reactions during downshifts.

The gearbox also has a Race Start function. It’s basically a way to get off the starting line with maximum acceleration, and everything including optimum launch revs, the launch itself, and then subsequent shifts are taken care of you, all the way to top speed.

This gearbox is only available in the new SL 63 AMG in which it is mated to a 6.3 liter normally aspirated V8, producing 525 horsepower at 6,800rpm and 630Nm of torque at 5,200rpm. The engine revs up to 7,200rpm, one of the more higher revving V8s around until BMW’s new V8 in the E90/E92 BMW M3 was unveiled.

The SL 63 AMG’s high performance sibling is the force inducted SL 65 AMG powered by a 6.0 liter twin-turbocharged V12 putting out a colossal 1,000Nm of torque and 612 horsepower. This engine is only paired with the 5-speed AMG SPEEDSHIFT, as I don’t think the AMG SPEEDSHIFT MCT or the Mercedes-Benz 7G-Tronic can take that huge amount of torque, and I don’t think many gears are needed with that amount of torque anyway. As it is the SL 65 AMG can go from 0 to 100km/h in 4.2 seconds.

More photos of the SL 63 AMG and SL 65 AMG after the jump.

Click here to read the rest of New 7-speed AMG SPEEDSHIFT MCT

The modern automobile engine has fixed compression ratios, that currently usually hover at about 10.0:1 or 10.5:1 for normally aspirated engines and much lower for turbocharged engines. Cars with direct injection can go higher, but we’re quite limited because compression ratios are fixed. A turbocharged engine running off boost makes less power than a normally aspirated engine of similiar cubic capacity because of the reduced compression ratio. While this has been minimized with very fast spooling turbos these days, it is still not ideal.

The answer is a variable compression ratio engine. Saab showcased a concept version of a variable compression ratio engine back in the year 2000, and it was called the SVC, or Saab Variable Compression. The project never did go anywhere. The SVC was a turbocharged 1.6 liter engine that used a pivoting cylinder head to change compression ratios from 8.0:1 all the way up to a high 14.0:1 according to engine operating status. The pivoting head adjusted the slope of the upper part in relation to the lower part of the engine, thus changing the combustion chamber volume at piston top dead center. Because of this, the top and bottom parts of the engine were separated and each required its own cooling system. Thanks to turbocharging and SVC, the 1.6 liter inline-5 engine produced 225hp and 300Nm of torque using 2.8 bars of boost.

In 2003, Nissan took a different approach to implementing a variable compression ratio system. Nissan showcased its Variable Compression Ratio Piston-Crank System, or VCR for short. It uses a multi-link piston and crank mechanism to vary the compression ratio. Like the Saab SVC, it is also based on a turbocharged engine concept. Compression ratio varies from 8.0:1 to 14.0:1, and the highest compression ratio is used during slow and steady city driving when the car runs mostly off-boost. During hard acceleration when the turbocharger kicks in, the compression ratio is reduced up to 8.0:1. During medium engine loads and low to medium levels of boost, a middle ground such as 11.0:1 is used.

The conventional conrod is replaced by a multilink system that consists of three links An upper link is connected to the piston pin, a lower link revolves freely while connected to a crank pin, and a control link connects the lower link to a control shaft. The control shaft has bearing that has a certain amount of eccentricity to it. When the control shaft rotates, the fulcrum of the control link bearing changes, and this causes the top dead center position of the piston to be either moved up or down vertically. This modifies the combustion chamber volume at piston top dead center, this altering the cylinder’s compression ratio. Basically, the system is designed in such a way that the angle of the control shaft causes the top dead center position to move, so to vary the compression ratio you adjust the angle of the control shaft.

Nissan is also developing a similiar VCR system concept for diesel engines. I’m not sure if a production engine using this technology is in the works or not. VCR has probably been made outdated by direct injection - the Volkswagen Golf GTI’s 2.0 liter TFSI engine is turbocharged yet has a high compression ratio of 10.5:1!

Related Links:
Nissan Variable Compression Ratio Engine
Saab Variable Compression

The 2005 DARPA Grand Challenge is a 130 mile desert course - while this might seem mild compared to the Baja 1000 or other similiar off-road courses, what makes the DARPA Grand Challenge special is that the racers have to complete the course entirely without human control. That’s right - robots.

There’s a whole load of videos over at The Great Robot Race’s website, but there is one participant that stands out from the rest. Out of 12 participants which consisted of all-wheel drive machines, there was only one two-wheeler - the Ghostrider from Blue Team, which is a computer controlled motorcycle.

Using an array of sensors, high speed high resolution 3D-capable cameras and a gyro to help maintain balance, the Ghostrider navigated the DARPA Grand Challenge course using GPS. Watch a video of the Ghostrider after the jump, and the rest of the participants over at The Great Robot Race.

Click here to read the rest of Ghostrider: the robotic motorcycle

Fiat Group Automobiles has announced that they will unveil its first dual-clutch gearbox in September 2009. The gearbox will be designed and built by Fiat Powertrain Technologies at an investment of 500 million euros. The new gearbox called the DDC will be able to handle up to 343Nm of torque. The dual clutch transmission is one of three transmission variants in the C635 family. The other two will be a manual and a single clutch automated manual.

The new dual clutch Fiat Powertrain Technologies C635 gearbox will use two dry clutches (DDC means Dual Dry Clutch) which are lighter and require less cooling than wet clutches, but there is no indication at the moment how many speeds the gearbox would have, though 6-speed is the most likely since the C635 family will feature a manual as well, and I don’t think a 7-speed manual is very common,

Source

General Motors is planning a new series of small turbocharged Ecotec engines, similiar to Volkswagen’s TSI and Fiat’s T-JET series. First in the line up will be a 1.4 liter turbocharged gasoline engine. This engine could be tuned to produce power outputs ranging from equivalent to a normally aspirated 1.6 or even up to a normally aspirated 2.0 liter unit, just like Volkswagen has its 1.4 liter TSI in three stages of tune with two different types of forced induction systems. The 1.4 liter turbocharged GM engine is currently destined for American small cars, but it could slowly find its way into the engine bays of GM’s other cars too, like the Chevrolet Aveo and the Chevrolet Optra sold in Malaysia.

Source

Here is the full scoop on the new seven speed dual clutch transmission to debut in the BMW M3. Instead of M DCT as previously speculated, the transmission will be called the BMW M DKG instead, presumably meaning the same in German.

A BMW M3 with a 6-speed manual goes from 0 to 100kmh in 4.8 seconds, but with the new M DKG dual clutch transmission, shift time is shaved off by 0.2 seconds to 4.6 seconds. As with most twin clutch transmissions, you have the odd gears on one shaft and the even gears on the other, and upshifts are instantaneous because the next gear is pre-selected. The M DKG is a wet clutch system.

Drivelogic allows 11 different shift patterns - 5 automatic and 6 manual. There is also a separate Low Speed Assistant mode which allows the M DKG transmission to be smoother during slow maneuvering at speeds of less than 5km/h - parking your car for instance. It increases the smoothless and degree of accelerator control achievable by the driver. On the Volkswagen DSG, the throttle is actually way too snappy for you to park your car comfortably. This is because of the nature of the gearbox, essentially robotically controlled clutches,

Of course, manual shifting is available either by pushing and pulling the gear knob, or via paddle shifts on the steering.

Related Posts:
BMW M DCT to debut at Geneva 2008?
BMW M DCT: BMW’s new twin clutch gearbox