What's Going On?
Acura presently has its products produced in various factories, both in the U.S. and in Japan. Among them are the Honda of Canada Manufacturing Alliston, Ontario, plant, where the MDX is built, and the Honda of America Manufacturing plant in Marysville, OH, where the TL and RDX are produced. Meanwhile, over in Japan, there are the Saitama and Suzuka factories that are also tasked with Acura production (with the RL and TSX at the former and the no-longer-available-in-the-U.S. Integra at the latter). Lexus has made much of the fact that there has been a separation of its design, engineering and manufacturing operations-in the case of some of the vehicles, at least-from its parent Toyota. So one of the things that management at Honda has done is not only establish its own design studios (one in California and the other in Sakura, Japan), but is establishing its own manufacturing facility, the Yorii Plant in Japan, a 980,000-m2 facility with a 200,000-unit capacity, that is scheduled to go into production in 2010. Which seems to indicate that there are plans to grow Acura as time goes on, as there is no indication that the company would, say, move production out of North America and put those models in Japan.
All of which is to say that Acura is on the move. And it is becoming more focused on its purpose. With the refreshing of its lineup since 2005, it is fairly clear that although the marque may not presently have the market resonance of its Asian brand brethren, there is forward movement-fast forward movement.
The 2009 Acura TL was designed in California and is being produced in Ohio. It is engineered to be competitive with cars including the Infiniti G35, BMW 3-Series, Lexus IS 250/350 and ES 350, and Mercedes C Class. Given the exterior styling—as well as 305 hp V6 and all-wheel-drive—clearly it is.
Born in the U.S.A.
Which brings us, in a round-about manner, to the 2009 TL, the fourth generation of the model. (What's interesting to note is that the very first TL, the '99, was designed and engineered in the U.S.) The vehicle is categorized as a "performance luxury sedan." And what's interesting is that whereas the previous-generation offered a Type-S for those who were inclined to be interested in the performance more than the luxury, this time out Acura engineers have decided that they'd develop two versions of the car: the TL and the TL SH-AWD, with that acronym referencing "Super Handling All-Wheel Drive," a torque-vectoring system that is deployed on Acuras including the MDX and RDX. While you might figure that the use on the CUVs is predicated on driving in inclement conditions, for the TL the SH-AWD is utilized primarily for handling under demanding conditions that don't necessarily have anything to do with snow-although there is that, too.
According to Mat Hargett, chief engineer ("Large Project Leader" in Honda-speak), they conducted considerable customer research prior to developing the vehicle. People in Los Angeles, for example, wanted more distinctive styling; people in Philadelphia wanted more rear seat room and better handling. A matrix was developed with the characteristics of Intelligence, Performance, and Technology, all linked to a central hub of Emotion. "An overall development concept was developed so that everyone was on the same page," said Hargett. The concept: "Emotion Advanced."
Emotional Design Cue
Much of the work on the Emotion fell to Art Osborne, senior designer at the Acura studio in Torrance, CA, and project leader for Design of the TL. Osborne said that the brief for '09 TL is "Keen-Edge Dynamic," which partakes of both technology (the precision-machined character of the surfaces) and emotion (sensual forms of the sheetmetal). He suggested that while the exterior design of the previous generation TL was highly influenced by European cars, he worked at developing more of an American character for the '09, with lines that flow from the front to the back and undulate (e.g., from the top of the front fascia, up and over front wheel arch, along the belt line, then down through the edge of the tail lamp). Osborne said that he is influenced by architecture, which may seem odd, given that buildings are static objects, and this vehicle is anything but. Osborne cites the Guggenheim Museum Bilbao designed by Frank Gehry, which is visually anything but static.
The interior styling is characterized by fluid lines. The TL is offered in two models, the TL and the TL SH-AWD, and with an optional Technical Package, which includes Acura/ELS Surround 10-speaker 440-W audio, Milano leather, voice recognition navigation, and more. Note how the interior materials are also “technical,” with the use of metallics. The lighting throughout is based on LEDs.
The interior design echoes the exterior flow, as there are sweeps from the center console forward and around the driver's and front passenger's spaces. He describes this as providing "personal ambience." No aspect was left unaddressed by the designers. When the hood is popped, it isn't a matter of just seeing the engine compartment; Osborne described it as the "engine room." The engine is surrounded by five pieces of polymer that cover the accessories and frame the engine that sits unadorned, almost like something that would be featured at the Guggenheim.
Engine Tech
Within the engine room there are two engine options. The front-wheel drive TL has a 280-hp, 3.5-liter V6; the SH-AWD version has a 305-hp, 3.7-liter engine. According to John Mullett, principal engineer for Powertrain, the 3.5-liter is an all-aluminum engine with cast-in iron cylinder liners.
The 3.7-liter is a variation of the engine used in the 2009 RL; what's interesting is that the way it is engineered for the TL SH-AWD, it is the most powerful engine in an Acura sedan (interesting because the RL is the "flagship" model; it provides 300 hp @ 6,300 rpm vs. the TL's 305 hp @ 6,300 rpm). Mods to the engine to make it more powerful include increases in both the airflow and compression ratio, and a high-flow exhaust system with close-coupled catalytic converters and dual exhaust pipes with four exits. While the 3.5-liter has thin-walled liners that are produced with a centrifugal spin-casting process, in order to make the 3.7-liter as light as possible (it weighs less than the 3.5-liter engine in the TL Type-S), it has high-silicon aluminum liners cast into the block. An advantage of the high-silicon aluminum liners is that they provide excellent heat dissipation as compared with cast iron. Consequently, there is closer piston-to-cylinder clearance than on the other engine, and the bore diameters are greater than they otherwise might be.
For packaging reasons, both the 3.5-liter and the 3.7-liter engines are approximately the same size. The heads for both are pressure-cast aluminum with integrated exhaust port castings. The crankshafts and con rods for both are forged steel; the pistons are forged aluminum. Both engines feature a magnesium dual-stage intake manifold.
Framed here is the all-aluminum 305-hp engine for the TL SH-AWD. The 3.7-liter engine features variable valve timing and lift (the VTEC system) on both intake and exhaust valves.
Both use the Honda/Acura VTEC-Variable Timing and Lift Electronic Control-system, which adjusts intake valve lift and duration, depending on the engine speed. However, the 3.7-liter engine has a more-capable VTEC system, as it has a rocker arm system for the exhaust valves, as well, thereby providing two-mode control of all 24 valves.
And both have a drive-by-wire throttle system, rather than the conventional mechanical linkage. This system monitors pedal position, throttle-body opening, engine rpm, and road speed, and thereby determines the throttle control sensitivity so that the driver achieves the predicted "feel." By utilizing electronics, there are other benefits, as well. For example, there is integration of the traction control system and the Vehicle Stability Assist system (VSA uses seven sensors that monitor lateral acceleration, steering wheel angle, wheel speed, and yaw rates and adjusts the brakes and/or engine power to assist the driver in maintaining directional control of the vehicle).
Both have five-speed automatic trans-missions. Both transmissions feature sport-shift capabilities, either by using the gear selector or the steering wheel paddle shifters. The transmission in the SH-AWD version is a like the one in the '09 RL, with a stronger case, larger shafts, larger gear clutches, and a new torque converter and lock-up assembly. As this is a performance-oriented model, there is a standard transmission cooler.
Electric power steering (EPS) is used on the TL. A benefit of this (in addition to the 0.7 mpg city and 0.8 mpg highway fuel savings that are achieved compared with a traditional hydraulic system) is that the ride and handling engineers were better able to tune the steering for the vehicles. The SH-AWD version, for example, has a more pronounced build-up of steering effort as speeds increase. (When operating at low speeds, such as parking, the control system makes steering effort light.) In addition, the turning radius of the '09 TL is 19.2 ft., compared with 19.9 ft. for the '08, even though the '09 is 6.2-in. longer than the previous model (@ 195. 3 in.) and the wheelbase is 1.4-in. longer (@ 109.3 in.).
Materially Improved
According to Mike Unger, principal engineer in the area of Total Vehicle Performance, the new TL has a body-in-white that is lighter-by 17 lb.-than the previous model, yet is significantly stiffer: bending mode is improved 10%; torsional mode is up 5%; front lateral rigidity is up 17%; and rear vertical rigidity is up 41%. Yes, this is largely a function of materials utilization, as in the use of 47.6% high-strength steel (HSS) in the body. In addition to which, there are some higher-strength steels in the structure, including grades 980, 590, 440, and 340. Two of the ultrahigh-strength grades are used for the first time in an Acura. However, there are design modifications, as well, such as the positioning of the redesigned longitudinal frame rails so that they are above the floor pan rather than below it, which not only improves crash performance, but also provides an aero benefit.
Aluminum also gets its due in the TL, with applications in the hood, front and rear bumper beams, cross-car instrument panel beam, front suspension subframe, rear suspension knuckles, and steering hanger beam. They've calculated that the use of aluminum provides a weight save of 51.7 lb.
Although the TL is bigger than its predecessor, and despite the fact that it was a significant array of additional content, the base TL has a curb weight of just 85 lb. more than the '08 model (@3,708 lb.).
As previously mentioned, the overall length of the '09 TL is 195.3 in. Other key dimensions are height: 57.2 in. and width: 74 in. Each of these dimensions is greater than those on the '08. This helps contribute to an increase in the overall passenger volume to 98.2-ft.3, up 0.3-ft.3. (The cargo volume, at 13.1-ft.3, a 0.6-ft.3 bump). This brings us back to the people Hargett and his colleagues talked with in Philadelphia. Not only has Acura created a TL with a distinctive style, more power, and better handling, but the people in the back seat get 1.1 in. more rear leg room and 0.4 in. of shoulder room. The TL team seems to have not overlooked anything.
(source:www.autofieldguide.com)
Rabu, 13 Mei 2009
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