Posts Tagged ‘acceleration’

1 June

2009 Chevrolet Corvette Review

By TCC Team
www.thecarconnection.com

Unless you’ve been on planet Nader for the last few years, you knew Chevrolet was brewing up an uber-Vette. Amid all the hype, spy photos, leaked photos (and subsequent prosecutions), rumors, and names (Blue Devil, SS, Sting Ray, Z07), any dolt could discern that this new Corvette had the potential to be amazing.

During its annual press preview for the Detroit auto show, GM showed journalists what we’ve all been waiting for; the official, almost-ready-for-production 2009 Corvette ZR1 destined to hit showrooms next September.

Tom Wallace, Corvette Chief Engineer, began the presentation by talking about what started the ZR1 program. To our group of gathered reporters, he recounted a meeting that took place more than six years ago when GM Chairman Rick Wagoner asked what a $100,000 Corvette would look and perform like. On cue but out of sight of our pack of writers, a sinister-sounding V-8 fired up. Bob Lutz, GM Vice Chairman, then drove the ZR1 out into the meeting area.

After Lutz slid out from behind the wheel, he gave his driving impressions of the ZR1, “What’s so terrific about this car is that it is very docile and easy to drive, but then when you step into it, the power just never stops.” Subsequent presentations explained why.

Final specifications are not yet available because the development team is still fine-tuning powertrain and chassis calibrations, but this is what GM told us. The new LS9 engine is a 6.2-liter supercharged and intercooled V-8 that shares key dimensions and some features with the current Z06’s LS7. The “9″ uses a fifth-generation low-profile Eaton supercharger that itself incorporates plenty of new technology. Its impellers sport four veins instead of three, greatly improving volumetric efficiencies while reducing parasitic losses. Compared to the previous generation blower that required approximately 120 horsepower at maximum boost, the new unit draws only 80. Final horsepower numbers will exceed 620 and torque should come in around 600 lb-ft. The rumor mill pegs the target horsepower figure at 650.

The top of the supercharger is visible when the hood is closed thanks to a Lexan window placed in the center of the carbon fiber hood. The hood itself eschews big bulges for tasteful lines that tightly envelop the LS9 (compared to previous LS engines, the LS9 is only one inch taller overall, even with the supercharger and intercooler). No Pro-Stock hood scoop necessary.

The transmission is a modified version of the Tremec six-speed used in so many high-performance vehicles, including the Viper. In the ZR1, this iteration sports a close-ratio gear set that aids in acceleration. Unlike in the current Corvette where top speed is achieved in fifth gear, an estimated top speed of over 200 mph for the ZR1 will come in sixth. Wallace commented that, “One interior change we had to make was to ditch the standard 200-mph speedometer with a 220-mph unit because this car will so easily exceed 200.”

His pride was clearly evident. He added later that this combination is expected to economical enough to avoid the gas-guzzler tax. No specific performance figures were quoted, but Wallace said the ZR1 would easily beat the current Z06’s performance of 3.7 seconds to 60 mph and the current car’s 7:42-second lap time at Nurburgring. One member of the team noted that in its current form, first gear is good for 67 mph, an indication of the new gearing and the LS9’s ability to rev.

With so much power comes heat, so the ZR1 has more and bigger coolers and heat exchangers for all powertrain components. A massive front spoiler with an integral splitter helps channel air to all the right places. Side sill extensions are similar to what was used on the C6R racecar. The side vents feature a large strake that bisects the opening.

Chassis-wise, Magnetic Ride Control (MRC) is standard. The near instant response of the dampers allows for softer spring rates, and GM claims the ride of the ZR1 is more compliant than the current Z06. Tire size increases at both ends, with 19-inch rims in front and 20-inch rims in the rear sporting 335/25Z/20 Michelin PS2s. Wheel widths are 10 and 12 inches respectively.

Brakes discs are huge carbon-ceramic units that are clamped on by six-piston Brembo calipers in front and four-piston units in the rear. The rear discs are as large as the fronts found on other supercars. Metal discs used on the Z06 were provided for comparison on a table-top display, and were considerably heavier. Of course, lighter rotating and unsprung mass is critical for improving every aspect of performance.

The Corvette development team took weight out of the ZR1 wherever possible. Carbon fiber is used extensively, even on panels exposed to strong UV light like the roof and roof pillars. (Apparently, UV breaks down the bonding elements within carbon fiber, rendering the material brittle in as little as five years.) GM’s solution is a special clearcoat that costs upwards of $2000/gallon.

According to the Harlan Charles, Corvette Product Planner, the ZR1 will be offered in seven colors and offer two wheels (one chrome). The standard ZR1 will feature interior equipment similar to a standard Z06, and there will be one major option package similar to the 4LT that includes the fully leather-wrapped interior. If pricing of 2008 models provides any indication, this RPO will cost around $8,000. Charles also noted that because there is only one set of production tools for the carbon-fiber body panels, yearly production is not expected to exceed 2000 units.

Just as the Z06 used the color red to highlight key components, the ZR1 uses blue accents on the LS9 and on the model’s logo. Perhaps this is a tip of the hat to the Blue Devil moniker that surfaced early? GM would neither confirm nor deny.

Regardless, this is what a $100,000 Corvette looks like. Wagoner should be quite happy, nod to his past or not.

3 May

Experience Power, Enjoy Freedom: The New BMW M3 Convertible


Specifications

Brakes & Tires
Brakes F/R: ABS, vented disc/vented disc
Driveline: Rear Wheel Drive
Tires F-R: 245/40 ZR18 - 265/40 ZR18
Engine
Displacement cu in (cc): 244 (3999)
Power bhp (kW) at RPM: 414(308) / 8300
Redline at RPM: 8400
Torque lb-ft (Nm) at RPM: 295(400) / 3900
Type: V8
Exterior Dimensions & Weight
Length × Width × Height in: 181.7 × 71 × 54.8
Weight lb (kg): 3989 (1810)
Performance
Acceleration 0-62 mph s: 5.4
Fuel Economy EPA city/highway mpg (l/100 km): 21 (12.9)
Top Speed mph (km/h): 155 (250) - electronically limited

The BMW M3 model family is being upgraded by yet another fascinating player. The new BMW M3 Convertible, the third body version of BMW’s high-performance sports car following the Coupe and Saloon, offers new possibilities to experience uncompromising driving dynamics.

Outstanding performance and thrilling dynamics of this kind create the first impression conveyed by the BMW M3 Convertible right from the start: This very special two-door performer not only comes with the same drive technology as the BMW M3 Coupe and the BMW M3 Saloon, but is also a brand-new development from the ground up, again boasting all the features so typical of a BMW M model.

The BMW M3 Convertible thus transfers motorsport technology to everyday motoring, meeting even the greatest demands made of such a high-performance car. In its character, therefore, it is first and foremost a BMW M3, while nevertheless betraying its unique identity side-by-side with the Coupe and Saloon.


An Eight-Cylinder in a BMW M3 Convertible
The BMW M3 Convertible draws its exceptional dynamic driving potential from its new eight-cylinder power unit developing 414 bhp from 244 cubic inches. Maximum torque of 295 lb-ft is just as impressive as maximum engine speed of 8,400 rpm. This high engine speed concept so typical of BMW M engines comes straight from the latest Formula 1 power unit raced by the BMW Sauber F1 Team. Clearly, this outstanding principle of engine power ensures unique torque and muscle also in the BMW M3 Convertible in transmitting engine power through the variable M Differential Lock to the rear wheels.
Acceleration to 60 mph comes in just 5.1 seconds and the car continues to surge ahead with increasing power and performance as the driver keeps his foot on the gas pedal, all the way to the car’s top speed of 155 mph, where the engine’s electronic control unit sets a limit to the ongoing speed and performance of this open-air athlete.
The new BMW M3 Convertible comes as standard with a manual six-speed gearbox. With short gear lever travel like in motorsport and crisp, precise movement of the shift lever, the driver is able at all times to transmit the superior power and thrust of the V8 to the rear wheels with the ideal gear ratio.
The Interior: Four Seats, if You Wish with the Roof Down

Creating the interior, the designers and other specialists at BMW M have successfully reached their objective to offer the occupants maximum driving pleasure in an ambience perfectly tailored to their requirements. This applies particularly to the driver’s seat, with all elements required for active motoring being modified accordingly and, through their enhanced functions, reflecting the exceptional power and performance of the BMW M3 Convertible.

As soon as the retractable hardtop folds up into the rear compartment, the driver and front passenger enjoy a truly incomparable open-air atmosphere further promoted by the low-slung shoulder line, the seating position moved far to the back, and the short windscreen. The result of this concept, obviously, is an optimum experience of open-air motoring.

The frame round the windscreen keeps a generous distance from the heads of the front passengers, allowing the sun and, to a pleasant degree, the wind to flow smoothly into and around the interior.

A further highlight is that the occupants now enjoy an even more direct, undiluted experience of the V8 power unit with its unmistakable acoustics.

Supreme Performance is the Objective, Sheer Driving Pleasure is the Result

Even though the full power and performance of the BMW M3 can only be used on the race track, the car’s impressive supremacy also in city traffic and on country roads ensures sheer driving pleasure in a particularly fascinating rendition. And even that is not all, for there are countless roads and routes the world over which, while being thoroughly enjoyable in the BMW M3 Convertible with the roof closed, offer an even higher level of enjoyment and satisfaction with the roof open in perfect convertible weather. So whoever demands top performance and knows how to enjoy supreme pleasure in life will be thrilled time and again by the new BMW M3 Convertible.

—–>www.rsportscars.com