在研发凯迪拉克ATS-V高性能版时，通用汽车的工程师遭遇到了一个不寻常的问题——这款基础车型的重量有些太轻了。

虽然这样描述并不准确，但也已经能够大致描述核心问题了。在通用汽车多年的汽车开发历史中，给汽车减重似乎是后来才出现的想法。最近一些用Alpha平台开发的型号（如ATS），其基础车型上都能体现通用公司对重量优化理念的贯彻。然而，直到工程师在ATS-V上加大发动机功率和牵引力后，才发现他们需要一个更强壮的车身。

凯迪拉克首席工程师Dave Leone表示，无论是双门轿跑版还是四门轿车版，都必须对ATS-V的底盘进行大量加固，才能将扭矩强度提升25%。首先，工程师们在车辆前部安装了一个连接冲击塔与集气室的支架，以辅助引擎盖下的V型支架，共同起到加固作用。此外他们还对以下三个平台进行了加固——包括摇杆隔板，后悬挂托架与单片式车身底板之间用螺栓紧固的冲压钢支架，以及前悬挂子结构下方的大型铝制平台（升级用的中央部件）等。通用汽车将该平台称为“剪力板”，其作用是将前悬挂和托架更稳固地与单片式车身相连。

Leone表示，大型铝制加固板的作用在车辆转弯时体现得最为明显，因为ATS-V的转弯表现非常干脆利落，而且车身并未发生扭曲。

继平台加固之后，通用汽车的工程师还将悬挂部件进行了加固。首先，他们将多连接双枢轴麦弗逊柱悬挂上的支架避震组替换为零压顺应球形接头、更坚固的前部弹簧以及更厚实的防倾杆，三者相加可提升50%侧倾刚度。此外，他们还将普通ATS上的转向齿条替换为更坚固的ZF Servotronic II转向齿条，这也提升了转向表现。

后方的支架避震组、弹簧、防倾杆和托架基座也同样得到了加强。工程师还对后悬架的形状进行了改进，增加了其抗后座力性能，并减少了后部侧倾中心的移动。

工程师用一个标准的电子限滑差速器降低出弯时的动力，此外还利用不同直径的半轴对扭矩反应的频率不同这个原理，抑制加速时发生的车桥跳动现象。由GKN提供的左半轴是一个带有恒速接头的总成件，长度为55毫米（2.2英寸），而右半轴则是标准规格，为30毫米（1.2英寸），两轴刚度比为2.6:1。

制动器均为布雷博产品，前制动器为六活塞单件制动钳搭配14.5英寸（368毫米）转子，后制动器为四活塞制动钳搭配13.3英寸（338毫米）转子。该配置同样用于重量级更高的户外型CTS-V，不仅能够提供不会衰退的强大制动力，还能在得克萨斯奥斯汀美国跑道（Circuit Of the Americas）的牵引力测试中增加踏板行程。

减震系统使用的是京西重工（BWI）的主动式电磁悬挂技术（MRC），该系统由凯迪拉克首先使用。该技术最近一次迭代时，将两个减震模式进行了更明确的区分。ATS-V项目工程师经理John Barrick表示，“现在我们有两个真正的减震模式了，之前顶多是一个半。”高档减震模式的性能比旧版高出了40%。

新系统更快的反应时间意味着当车速为60 mph（97 km/h）的时候，ATS-V每行驶1英寸，减震系统都能进行一次自我调节，而旧系统为3英寸，Barrick补充道。

18英寸铝制车轮不仅重量轻，而且还能用三个截然不同的区域牢牢地固定米其林PSS（Pilot Super Sport）轮胎。外轮唇经过硬化处理，可以更好地承受因轮胎周圈的冲击而造成的侧向反力，而且不会对轮胎表面的橡胶造成磨损。中间层经过了湿地牵引力优化，而内层则是具有粘性的赛车级橡胶。

转弯时，该轮胎可以提供骄人的1.25g横向加速度。

正如工程师们为表面下方的细节倾尽全力，设计师们对表面本身同样不遗余力。“所有设计元素都有其目的，”凯迪拉克全球设计执行总监Andrew Smith表示。“它们可以减小升力、加强冷却、为车身减重，或兼具多个功能。”

其中最引人注目的是碳纤维引擎盖及其不加装饰的碳吸热口。首先，碳纤维引擎盖比钢制引擎盖更轻巧。第二，吸热口不仅能为发动机区域降温，而且从引擎盖上逸散的空气也有助于降低车辆在高速行驶下产生的升力。

车辆前脸上扩大的敞口可让更多空气进入到其后方的众多热交换器，而底部的分流器也可以对来自路面上的空气进行引流，减少升力。ATS-V的挡泥板也经过了加宽处理，可以覆盖更宽的车轮和轮胎，而门槛和后扰流板则为车辆升力的整体平衡提供了最后的辅助。用户还可以选择配置更大尺寸的分流器、引擎盖吸热口、后扰流板、门槛和后部空气扩散器。

经过改善的不仅仅是空气动力设备。工程师使用塑料对车身下方的后控制臂进行包裹，Barrick说这样做可以将拖曳力降低两成。

自然而然，在加装完所有必要的辅助设备之后，这款高性能ATS-V一定需要一个更强大的传动系统。

ATS-V的发动机为获得SAE认证的双涡轮直喷3.8升V6发动机，功率为464 hp（346 kW），扭矩为444 lb·ft（601 N·m）。变速箱可选择6速手动或8速自动变速箱进行搭配。该车加速至60mph需要3.8秒，最高车速为189mph（304公里/小时）。

这台发动机由低惯量钛铝合金涡轮与真空作动废气阀组成，不仅可以降低拖力，还能增强低转速时的反应。涡轮增压器的压缩器专为匹配峰值功率时的峰值效率而设，可将赛车性能发挥至最佳水平。

工程师们使用了一种正在申请专利的小容量增压冷却技术对发动机的反应性能进行增强，该技术可以在发挥出最大升压的同时提高封装效率。而发动机本身则可受益于钛制连杆，降低惯量。

Hydra-Matic的8L90八速自动变速箱的速度更快，效率更高，因此受到了工程师的青睐。尽管驾驶员可用方向盘上的拨片完成手动变速，但只要切换至冲刺模式，当他在圆形赛道上飞速驰骋时，变速箱的计算机便可自动做出完美的换档决策。从多方面考虑，这种方式都具有明显的优势。

然而，对那些不满足于这种方式的驾驶员来说，凯迪拉克还提供Tremec TR6060六速手动变速箱。我们曾在其他车型上（包括通用汽车的雪佛兰Corvette）看到过降档时自动匹配转速的功能，但ATS-V将其加入无升力的升档中。当驾驶员脚踩离合器时，可用H模式换挡器完成手动升档，然后像平常一样松开踏板。但加速器踏板安装在车辆地板上，且车辆会自动降低动力，直至升档完成。

尽管这种方式与擅长手动变速的驾驶员长期积累下来的肌肉记忆背道而驰，但它能够以惊人的速度完成升档。因此，计算机匹配的降档和自动削减动力的升档可让驾驶员不再费心于手动换挡，而且它们都能使换档变得更流畅、更迅速。

搭载自动变速箱的ATS-V的EPA燃油经济性评估结果为16 mpg城市和24 mpg公路，手动版的结果分别是17 mpg城市和24 mpg公路。

一个电子控制的限滑差速器可将动力高效地传至路面。多亏极其丰富的齿轮比以及非常低的第1档，手动版的主减速比为3.73:1，自动版为2.85:1。

可以预见，狂热的汽车爱好者们还需要进行一番自我调整，才能适应运动型自动变速箱理念和这款运动紧凑型凯迪拉克。

In developing the Cadillac ATS-V high-performance variant, General Motors’ engineers were faced with an unfamiliar problem; a base car that was a little too light.

Not exactly, but that was the gist of the issue. After years of developing cars in which mass reduction was a seeming afterthought, GM has with recently developed models such as the ATS, on its Alpha platform, so thoroughly optimized on mass for the base model that the car was left needing a stronger foundation when more power and traction were added for the ATS-V model.

In both its two-door coupe and four-door sedan variants, the ATS-V received a raft of needed chassis reinforcements that produce a 25% increase in torsional rigidity, reported Cadillac Chief Engineer Dave Leone. This improvement was achieved through the installation of a front shock tower-to-plenum brace along with underhood V-braces, reinforcement to the rocker bulkhead, stamped steel bolt-on braces between the rear suspension cradle mount and the floor of the unibody, and (the centerpiece of the upgrades) a large aluminum platform beneath the front suspension subframe that the company terms a “shear plate” that connects the front suspension and its cradle more securely to the car’s unibody.

The effect of that huge aluminum reinforcement plate is felt primarily on corner turn-in, where the ATS-V responds crisply rather than by twisting the car’s structure, according to Leone.

With the platform suitably braced, GM’s engineers beefed up the suspension components too. That includes replacement of bushings in the multi-link double-pivot MacPherson strut suspension with zero-compliance ball joints, stiffer front springs, and thicker front anti-roll bar that combine to produce a 50% increase in roll stiffness. The ZF Servotronic II steering rack is also stiffer than that on the regular ATS, which also contributes to improved steering feel.

At the rear, there are stiffer bushings, springs, and anti-roll bar along with stronger cradle mounts. Revised rear suspension geometry incorporates more anti-squat and has less migration of the rear roll center.

A standard electronic limited-slip differential helps put the power down on corner exits, while different-diameter halfshafts suppress axle hop under acceleration by not having the same frequency response to torque. The left side shaft, which is provided by GKN as an assembly with its constant velocity joints, is 55 mm (2.2 in) compared to 30 mm (1.2 in) for the standard-issue right shaft, for a 2.6:1 difference in rigidity between the two.

Brakes are the same Brembo six-piston one-piece front calipers with 14.5-in (368-mm) rotors at the front and four-piston rear calipers with 13.3-in (338-mm) rotors at the rear as were used on the heavier outgoing-generation CTS-V, which provided impressive stopping power without fade or increased pedal travel during track testing at the Circuit of the Americas in Austin, TX.

Damping is by the BWI Group’s Magnetic Ride Control that Cadillac brought to market. This latest iteration of the technology provides improved differentiation between its two modes, according to John Barrick, Program Engineering Manager for the ATS-V. “Now we have two true modes,” he said. “Before it was more like one and a half modes.” The increase in maximum damping is 40% greater than before.

The new system’s quicker response time means that the damper adjusts itself for every inch the ATS-V travels at 60 mph (97 km/h), while the previous system covered three inches between adjustments to settings, Barrick added.

The 18-inch forged aluminum wheels help reduce mass and mount Michelin Pilot Super Sport tires molded with three distinctly different zones of compound. The outer shoulder is hardened to withstand the cornering force of hammering around tracks without burning the rubber off the outside of the tires. The middle section is optimized for wet traction, and the inner portion is sticky race-ready rubber.

On the track, the tires contributed to an impressive 1.25 g lateral acceleration in the turns.

Just as engineers attended to every detail under the skin, so did the designers when working on the skin itself. “All of the design elements have a purpose,” said Andrew Smith, Executive Director of Cadillac Global Design. “They contribute to lift reduction, enhanced cooling, reduced mass, or all of the above.”

Most obvious is the carbon-fiber hood, with its bare carbon heat extractor vent. The hood saves weight compared to a steel hood, and the extractor not only helps hold down engine bay temperatures, but the air exiting it atop the hood reduces lift at speed.

The enlarged openings in the front fascia feed more air to the various heat exchangers behind it, and the splitter on the bottom scrapes directs air from the road surface, minimizing lift. The ATS-V’s fenders are widened to cover the wider wheels and tires, and the rocker panels and rear spoiler provide the final touches on overall balance of lift on the car. The optional carbon-fiber package provides enlarged splitter, hood air extractor, rear spoiler, rocker panels, and rear diffuser.

Those aren’t the only aerodynamic devices. Under the car, the lower control arms at the rear are sheathed in plastic covers that Barrick says reduce drag by two counts.

Naturally, as a high-performance variant, once the necessary supporting infrastructure was established, the ATS-V needed a suitably more powerful powertrain.

It is an SAE-certified 464-hp (346-kW), 444-lb·ft (601-N·m) twin-turbocharged, direct-injected 3.8-L V6 engine matched to a six-speed manual or eight-speed automatic transmission. The car accelerates to 60 mph in 3.8 s and reaches a top speed of 189 mph (304 km/h).

The engine features turbocharges with low-ineria titanium-aluminide turbine and vacuum-actuated wastegates for reduced lag and stronger low-rpm response. The turbos’ compressors are matched for peak efficiency at peak power levels, providing maximum on-track performance.

The engine’s response is augmented by a patent-pending low-volume charge-cooling system that improves packaging efficiency while permitting maximum boost pressure. The engine itself enjoys some reduced inertia courtesy of its titanium connecting rods.

The Hydra-Matic 8L90 eight-speed automatic is the faster and more efficient transmission choice. The car features steering-wheel-mounted paddles for manual shift actuation, but when the ATS-V is switched to attack mode, the transmission’s computer makes flawless shift decisions while the driver hammers the car around a circuit. In most respects, it is the better way.

However, for those drivers who think it is not the fun way, Cadillac offers theTremec TR6060 six-speed manual transmission. We’ve seen automatic rev matching on downshifts elsewhere, including GM’s own Chevrolet Corvette, but the ATS-V adds to that no-lift upshifts. The driver depresses the clutch, makes the manual gearchange using the H-pattern shifter, and releases the clutch pedal all as usual. But the accelerator pedal stays on the floor throughout and the car automatically cuts power just long enough to compete the shift motion.

Though this defies the accumulated muscle memory in anyone able to operate a manual transmission, it makes upshifts shockingly quickly. So, maybe computer-matched downshifts and automatic power-cut upshifts leave the driver doing less of the manual shifting job, both ensure that the shifts are smoother and faster.

The EPA fuel economy estimates for the automatic transmission-equipped ATS-V are 16 mpg city and 24 mpg highway, while the manual gets 17 mpg city and 23 mpg highway.

An electronically controlled limited-slip differential helps the power get to the road effectively, with a 3.73:1 final drive ratio for the manual transmission and a 2.85:1 for the automatic, thanks to its abundance of gear ratios that permit a very low first gear.

Apparently, enthusiasts will have to accustom themselves to both the notion of sporty automatic transmissions and sporty compact Cadillacs.