Automotive Engineering UNIT:1 PPT

Posted April 11, 2013 by Mechanical
Categories: 8th sem study materials



Combustion Chambers

cooling and lubrication mo


Return of the Camaro Z/28

Posted April 5, 2013 by Mechanical
Categories: AUTOMOBILE

The Camaro Z/28 showing air intake

The Camaro Z/28 showing air intake

At this week’s New York Auto Show, Chevrolet rolled out its restyled 2014 Camaro line with the highlight being the return of the Camaro Z/28. The four-passenger, front-engine, rear-drive coupé is billed as the “most track-capable offering in Camaro’s history” and the ”most significant redesign since the introduction of the fifth-generation Camaro as a concept car in 2006.”An exercise in single-minded concentration on track performance through a new aerodynamics package and radical weight reduction, the Camaro Z/28 is the latest take on the classic racer that came out in 1967. The original was created for the Sports Car Club of America’s Trans-Am 2 class and was intended for road racing with a 302-cubic-inch V-8 and heavy-duty suspension, but lacked such amenities as an automatic transmission or air conditioning.The 2014 Camaro Z/28 isn’t intended for race competition. Instead, it’s more track minded. “We set out to make the fastest road-racing Camaro possible that was still street-legal,” said Al Oppenheiser, Camaro chief engineer. “While the Camaro ZL1 offers exceptional performance on the street, the drag strip, and the track, the Z/28 is entirely focused on the track performance. The Z/28 will be too track-focused for most drivers, but offers road-racers one of the most capable track cars ever offered from an automaker.”Part of Chevrolet’s plan to achieve this was a drastic program of weight reduction with the Camaro Z/28 tipping the scales 300 pounds (136 kg) lighter than the ZL1. “We looked at every subsystem for opportunities to save weight,” said Oppenheiser. “Our goal was to get rid of everything that didn’t make the car faster, and keep only what was required by law. For example, we wanted to eliminate the audio system completely, but we had to keep a single speaker for the seat-belt chime to meet safety requirements.”

The Camaro Z/28 has a thinner rear window to save weight

Legal requirements are also the reason why the Z/28 comes with a tire-inflator kit in Rhode Island and New Hampshire, but not in other states where the law does not require it. Other weight-saving measures include removing carpeting from the boot and interior sound dampening insulation, replacement of the LN4 battery with the lighter LN3, and the rear window thickness was reduced from the standard 3.5 mm to 3.2 mm.

The Camaro Z/28's interior

“The team was so fanatical about saving weight, we even stripped the unused wiring out of the harness when we eliminated the fog lights, speakers, and air conditioning,” said Oppenheiser. “Every ounce saved contributed to making this the most track-capable Camaro we have ever built, and a worthy successor to the Z/28 name.”

Close up of the Z/28's front

With a wheelbase of 112.3 inches (2,852 mm), the Camaro Z/28 tries hard to echo the lines of the 1967 original and it does have a solid American muscle car feel to it, though with a lot of aerodynamic design thrown in for downforce and stability at track speeds. This is reflected in front with its disproportionately wide opening and the bonnet vent for cooling and aerodynamic lift reduction. Chevrolet kept the profile lines simple without being boxy, though the attempt to emulate the 1967 rear boot lid does come off as jarringly flat. Underneath, there’s a large splitter on the underbody panel and an aggressive rear spoiler helps with downforce generation.

the Z/28's 'Octane' interior

With all the weight reduction business, the interior of the Camaro Z/28 is a bit spartan with its “Octane” matte-metallic finish, but Chevrolet tries to balance this by fitting it with the ZL1 flat-bottomed steering wheel, and standard Recaro seats with microfiber suede inserts, which have only manual adjustments as another weight-saving measure. The rear seats are even more severe with nine pounds (four kilograms) shaved off by taking out the seat-back pass through and replacing the rigid seat back with high-density foam and a steel-mesh seat bottom. Even air conditioning is an optional extra.

Made with a one- and two-sided galvanized steel unitized body frame, the chassis of the Camaro Z/28 is also optimized for track performance. “We used the very best components in the industry to deliver uncompromised performance, lap after lap,” said Mark Stielow, Camaro Z/28 engineering manager. “We made nearly 200 changes to improve the track performance, which cumulatively make the Z/28 capable of 1.05 g in cornering. For perspective, with all other things, equal increasing maximum grip from 1 to 1.05 g can cut up to four seconds per lap.”

Powering the Z/28 is a naturally aspirated LS7 seven-liter V-8 with a cast aluminum block, overhead valves and sequential fuel injection punching an estimated 500 hp (373 kW) and 470 ft-lb (637 Nm) of torque. It was co-developed with Corvette Racing and boasts titanium intake valves and connecting rods, sodium-filled exhaust valves, forged-steel crankshaft and main bearing caps, a high-lift camshaft, hydroformed exhaust headers, a 10.5-quart, dry-sump oiling system with integral liquid-to-liquid cooling, and a racing-style, cold-air induction system and large K&N air filter for maximum air flow. There’s also a muffler bypass for increased torque and engine noise during acceleration.

“The LS7 is ideal for road racing because it delivers amazing performance in a compact, lightweight package,” said Jordan Lee, Small Block chief engineer and program manager. “The broad torque curve and high redline of the LS7 mean fewer shifts are required for each lap, while the lightweight design improves the front-to-rear weight balance for better handling.”

There aren’t any details on performance yet, but Chevrolet said that the Z/28 is three seconds faster per lap than the Camaro ZL1.

Trimming weight means that the Camaro Z/28 is only available with a Tremec TR6060 six-speed manual gearbox with close-ratio gearing and 3.91:1 final drive ratio. The rear-wheel drive features limited-slip differential with a helical gear set instead of traditional clutch packs. A second liquid-to-liquid system reduces differential temperatures by up to 100° F (37.7° C). According to Chevrolet, this allows for more applied power and faster cornering by adjusting the torque bias to maximize available traction and providing drivers with adjustable throttle and brake intervention.

Weight saving was a major factor in the Camaro Z/28's design

Chevrolet says that the Camaro Z/28 is one of the first production cars with spool-valve dampers that offer four-way adjustment tuning for bump and rebound settings for high-speed and low-speed wheel motions and enabling increased damper stiffness. Front and rear suspension includes a double-ball-joint, multi-link strut, direct-acting stabilizer bar, progressive-rate coil springs, and inverted monotube shock absorber. In addition, the StabiliTrak electronic stability control is standard.

Air conditioning on the Z/28 is optional

Weight reduction also extends to the Camaro Z/28’s 19-inch wheels with Pirelli PZero Trofeo R tires, which replace the 20-inch versions of the Camaro SS and ZL1, saving another 42 pounds (19 kg) while lowering the center of gravity for better handling. Brakes are Brembo Carbon Ceramic Matrix front and rear discs with six-piston fixed front and four-piston rear calipers capable of 1.5 g deceleration and providing a 28 pound (12.5 kg) weight saving over comparable steel brakes..

The Z/28 is a purpose-built track car

The 2014 Camaro Z/28 goes on the market later this year and will appear in track events in the United States in the spring of 2014. Pricing details are yet to be announced.

The Camaro Z/28's rear profile

The video below shows the unveiling of the 2014 Camaro line.


Source: Chevrolet

Two ton turbo diesel hexapod you can drive

Posted April 5, 2013 by Mechanical

Matt Denton, chief designer and founder of Micromagic Systems, sits in the cockpit of his ...

Mantis, built by Matt Denton of Micromagic Systems, is the largest operational hexapod in the world

The term mad scientist gets thrown around quite a bit, but in the case of one Matt Denton it most certainly applies. His company, Micromagic Systems, has been working steadily over the past four years to design and build a walking robot that’s big enough to carry a human passenger. The resulting beast is described as “the biggest, all-terrain operational hexapod robot in the world.”

Mantis' six legs are powered by a turbo diesel engine and 18 hydraulic actuators

The robot weighs a massive 1,900 kg (4,188 pounds), stands 2.8 meters (9.18 ft) tall, and is powered by a Perkins 2.2 liter turbo diesel engine and hydraulics. It’s outfitted with a variety of sensors (including force transducers, angle sensors, and an inclinometer) that help it walk. A Linux PC running HexEngine – software designed to control hexapod locomotion – takes care of the 18 hydraulic actuators in its legs, while a panel PC puts you in the driver’s seat.

Mantis, built by Matt Denton of Micromagic Systems, is the largest operational hexapod in ...

Mantis takes a break during the filming of its promotional video

“This is definitely the largest hexapod we have built so far,” says Micromagic founder and Mantis’ chief designer Matt Denton. His company, which produces animatronics for the film and television industry, has worked on hexapods before – including one that appeared as a six-legged turtle in the Harry Potter films. Mantis, however, was a passion project that is now being rented for events.

Mantis' legs contain a number of sensors and are controlled by HexEngine software, which w...

This isn’t the only ginormous hexapod robot being built. A team from Massachusetts is working on one of a similar size called Stompy, following a successful Kickstarter campaign last year. However, Matt and his team beat them to the punch with Mantis, which you can see in action in the video below.


Source: Mantis Robot, Mantis Facebook page


Posted March 20, 2013 by Mechanical