解析 聪明的“拳击手”  Analysis Boxing clever

保时捷911新的涡轮增压发动机够聪明吗？IsPorsche’sAll-newTurboFlat-sixSmartEnough?...







911每次用上新发动机都是个大新闻，对于喜爱它的粉丝来说，连入门级车款Carrera都加上了涡轮增压器，全新水平对置6缸发动机是否会让911自然吸气车型的铁粉爱、恨到咬牙切齿呢？在珠海国际赛车场,我们有了第一次国内体验。

Any new 911 engine is a big deal. This time, even Carrera, the entry-level model, got a turbo. Will the all-new turbocharged flat-six engine make those fans of naturally-aspirated 911 love,or hate it desperately?In Zhuhai International Circuit, we are experiencing it for the first time in China.




没有让任何人失望，保时捷给我们奉上了一台排量减小、效率提高的水平对置6缸机，而911赖以成名的响应能力和个性都完好地延续下来。下面我们从技术方面剖析一下这台机器。

No disappointment. Porsche offered us a downsized, more efficient flat-six with much of its wondrous response and character intact. Here’s how.



1.质量轻，为将来升级做好了准备

1.Light and future-proofed

新发动机的缸体由过共晶铝制成，更刚硬、热膨胀系数较低，比过去减轻了1.5千克。气缸内壁采用了等离子喷射铁涂层，能够降低油耗，应对印度和中国等市场燃油等级偏低的问题。油底壳使用了复合材料，让发动机重量又减少了2千克。

New engine block is manufactured from hypereutectic aluminium; stiffer, more resistant to thermal expansion and 1.5kg lighter than the old block. Plasma-sprayed iron cylinder liners help reduce fuel consumption and cope better with the poor fuel grades found in India and China. A composite oil pan saves a further 2kg over the previous engine.



Carrera和Carrera S两种动力级别的基本硬件是相同的：缸径91.0毫米，行程76.4毫米，排量2981毫升，压缩比10:1，红线转速7500转/分钟。足够大的气缸中心距为以后增大排量做好了准备。

Both 2981cc launch engines share the same 91.0mm bore and 76.4mm stroke, 10:1 compression ratio and 7500rpm rev limit.The bore spacing allows for larger capacity engines in the future, naturally.



两台发动机输出最大功率的转速也同为6500转/分钟，改款前的991 Carrera S需要7400转/分钟。这算进步吗？车主脖颈子上的汗毛可能不同意，不过当他们体会到从仅1700转/分钟就爆发的雄浑扭矩时就会改变看法了。

Maximum power is developed at 6500rpm for both engines, where the naturally-aspirated 991 Carrera S needed 7400rpm on the tacho. Progress? The hairs on the back of your neck may disagree, at least until they feel the shove of torque from just 1700rpm.



2.消除迟滞

2.Banishing the lag保时捷对新型发动机的涡轮管理系统及其电控气动泄压阀进行了精心设计，并为它们申请了专利。新系统的目的就是要尽量减弱堪称强制进气发动机的“阿基里斯之踵”的迟滞现象，同时还要保持最佳的涡轮转速和增压压力。ECU会分析油门开度，然后通过VarioCam Plus（可变凸轮轴系统增强版）判断几个参数，包括泄压阀、点火正时、可调排气凸轮轴、进气门升程和时长，以获得即时的响应。

Porsche is being cagey about the six’s patented turbo management system and its electro-pneumatically controlled wastegate.Designed to minimise lag, the Achilles heel of blown engines, it works to maintain optimal turbo speed and pressure. The ECU analyses throttle position and juggles several parameters – the wastegate, ignition timing, the adjustable exhaust camshaft, intake valve lift and duration via the VarioCam Plus system – to provide instant response.



3.高压喷射

3.High-pressure injection

每侧气缸都有各自的高压泵给位于中间的喷油嘴供油，喷油压强为250巴，这样能优化汽油的雾化效果、减少汽油在气缸壁上的凝结、降低二氧化碳排放。

Each bank has its own high pressure pump for the centrally located injectors, delivering fuel at 250bar, for optimal atomisation,minimal cylinder-wall wetting and low CO2 emissions.




4.按需进行冷却

4.On-demand cooling

为了减小发动机的负担，灵巧的电子装置能够在不必要时切断空调泵和散热器水泵。发动机会很快升到90°C的初始工作温度，在常规运转状态时会降回到85°C，此时冷却液的循环会变慢。

Smart electronics declutch both the air-conditioning and water pumps when not needed to reduce engine drag. The engine quickly reaches its initial 90°C operating temperature, then settles back to 85°C in normal running, during which the coolant circulates more slowly.



5.要有润滑油

5.Let there be oil水平对置发动机与直列机和V形机有一点很大的不同，就是它不能依靠重力帮助机油回流到油底壳中。新911采用了一套很复杂的润滑系统，它的一项重要作用是让安装位置很低的涡轮增压器得到充分的润滑从而欢快地运转。系统中有四个机油泵：一个主稳压泵，它以变压泵的方式（高负载及急加速时提升供油压力）按2到3巴的压强供应机油；两台各给一个缸盖供油；另外一台给两台涡轮增压器供油。每台增压器有一个独立的储油罐，高温润滑油从这里被吸出回流到油底壳中。

Unlike inline or vee-configuration engines,flat-sixes don’t have gravity to help the engine’s oil flow back to the sump.The 911 boasts a complex lubrication system, not least to keep the low-mounted turbos oil-fed and happy. As well as the main steady-state pump, which provides 2~3bar of oil pressure by means of a variable pump (oil pressure is increased under heavy load and hard acceleration), the engine uses three soak pumps: one for each cylinder head and a third specifically for the two turbos. Each blower as its own oil canister, from which hot lubricant is drained and recirculated back to the sump.

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