- 丰田的TS050赛车极有可能夺得LMP1组别的冠军,但新加入的非混动赛车,也一定程度上加剧了本次比赛的竞争态势。
- 从2018WEC斯帕6小时耐力赛的结果来看,丰田Gazoo Racing车队的TS050赛车想要在勒芒24小时耐力赛上取胜,有一定的难度。
- 中国华信TRSM车队选用GinettaG60-LT-P1赛车底盘,力争拿下2018年勒芒24小时耐力赛LMP1组别的冠军。
- 本次勒芒24小时耐力赛华信TRSM车队所选用的是Mecachrome V364反流式气缸单涡轮增压V6发动机
国际汽联世界耐力锦标赛(FIA WEC)系列赛事中的勒芒24小时耐力赛(24 Hours of Le Mans),可以说是赛车运动最先进技术的试验场,而2018-2019年赛季将是这一耐力赛发展的过渡时期。国际汽车联合会(FIA)制裁机构甚至将这一赛季称为WEC的超级赛季,因为除了相关比赛外,2020版WEC新规也将在这一赛季制定完成。制定新规的目标是:重新吸引厂商车队回归世界顶尖耐力赛,即于2018年6月16日-17日举行的第86届勒芒24小时耐力赛。(本文发表于SAE《汽车工程》杂志6月刊,发表时比赛尚未开始)
去年,保时捷(Porsche)与丰田(Toyota)是参加昂贵的勒芒24小时耐力赛勒芒原型车1组(LMP1)比赛的唯一两家厂商车队,并且保时捷在这次比赛中赢得了自己的第19个冠军。不过在此之后,保时捷将退出WEC,并将转战电动方程式锦标赛(Formula E series)这一成本较低的赛事。
就2017赛季结束后退出WEC这一决定,保时捷公司专门发表了相关声明:“根据保时捷发布的2025年战略计划,保时捷将在未来着重开发纯GT车型和纯电动GT跑车。”
保时捷退出勒芒24小时耐力赛,意味着丰田成为了本次大赛LMP1组别中唯一的厂商车队。针对这种情况,FIA匆忙修改了LMP1的规则(注意:非混合动力赛车也可参赛),降低了参赛成本,鼓励私人车队挑战丰田,赢得这一高端赛级的荣誉。该策略成功吸引了5个车队的8辆赛车,它们利用传统赛车供应商提供的底盘和发动机,对丰田强劲的工程实力发出挑战。
燃料&油耗规则
根据2018/2019赛季勒芒24小时耐力赛的临时新规,对于单圈长度为13.63km(8.47英里)的赛道,LMP1组别非混动车队的油耗上限为210.9 MJ(58.6 kW·h),而相比之下,丰田TS050 LMP1-H混动赛车的单圈油耗上限为124.9MJ(34.7 kW·h)。这款丰田混动赛车与非混动赛车相比,平均单圈可额外再消耗8MJ燃油。
除了在总油耗方面有所限制外,FIA也对赛车的燃油瞬时流量作了相关规定。其中,厂商车队的混动赛车的最大燃油瞬时流量为80 kg/h,而私人车队的非混动赛车的最大燃油瞬时流量则为110 kg/h。除了丰田LMP1-H 混动赛车的发动机排量有最高不可超过的5.5L的限制外,其它LMP1组别赛车的发动机排量均不受限制。此外,非混动赛车的最小整备质量为833 kg(1836磅),较丰田混动赛车允许的最小整备质量少45 kg(99磅),而丰田混动赛车的最小整备质量则为878 kg(1936磅)。
按规定,赛车发动机每个气缸至多只可以配有4个提升阀,并且所有赛车一律禁用电磁阀、液压阀与气动阀驱动系统。此外,每个赛车队还须装载统一的气门正时与升程系统。不过,FIA对赛车点火系统没有过多限制,各车队可在高科技的等离子、激光点火系统,以及其他高频点火系统中自由选择。
LMP1组别私人车队赛车的油箱容积上限为75 L(19.8 加仑),所对应的赛车每次加油量上限为52.9 kg (116.6磅);而丰田LMP1-H混动赛车的油箱容积上限为50 L (13.2加仑),所对应的赛车每次加油量上限为35.2 kg(77.6磅)。在发动机辅助系统的具体运作方面,可让发动机通过机械方式,或是让电机通过电动方式将动力传递给发动机辅助系统,但如果发动机辅助系统本身是电动的,则不能与发动机通过机械方式相连。此外,大功率制动器也不可使用,并且参赛车辆必须采用最多为六活塞的铝制汽车制动钳。而制动盘方面,虽然制造材料没有限制,但其直径必须控制在15英寸(37.5厘米)以内。
之所以作出上述种种规定,就是为了给低成本LMP1组别的私人车队创造赢过强大的丰田车队的机会。毕竟,在长达24小时的耐力赛中,任何情况都有可能发生。正如在2016年,丰田直到最后一圈也还保持着领先的优势,却突然遭遇故障,而将冠军拱手让给了保时捷。
ByKolles车队经理ManfrediRavetto表示:“我们最主要的目标是与过去相比争取实现质的飞跃,但老实说,我们就是想要取得进步。我们对能作为私人车队参加LMP1组别的比赛而倍感自豪,因为这场比赛是展示我们不断完善的赛车结构的最佳平台。我们很感激西方汽车俱乐部(ACO)与FIA组织这样一场世界最顶级的耐力赛。”
不过,在赛前测试以及2018WEC揭幕站斯帕6小时耐力赛中,很明显看出丰田TS050较其它私人车队的非混动赛车具有压倒性的优势,但丰田最后也很有可能是为了能顺利入选勒芒24小时耐力赛,而故意以微弱优势赢得第一名。
在斯帕6小时耐力赛中,丰田TS050赛车队以平均1:57.805分钟的成绩,成功包揽了第一名与第二名,比第三名Rebellion车队的R13非混动赛车的单圈速度快1.2秒。在资格赛中,丰田 TS050赛车一直保持领先其它参赛车辆2秒的优势,不过最后丰田由于在燃油流量限制器更换上犯了错误,其杆位车队TS050最后未能在规定时间完成比赛。
丰田TS050赛车介绍
丰田立志要在2018勒芒24小时耐力赛中以创纪录的车速跑出最多圈数。而在2017年,丰田就创下了圈速最快的记录,并且其2017年参赛车辆的油耗,要比其2012年参赛车辆的油耗低35%。
丰田车队的工程师们指出,今年参赛的TS050赛车同去年相比,在空气动力学性能上有了较小但质的改善。按今年勒芒耐力赛的新规,今年的TS050赛车还安装了Gentex汽车后视摄像头。不过除非丰田车队在比赛中出现故障,否则这一摄像头装置对丰田来说用处不大。此外,丰田车队还对其1000马力(746kW)的混合动力系统进行了改进,提高了系统的可靠性。
丰田Gazoo Racing车队的技术总监Pascal Vasselon表示: “与往年不同的是,我们针对2018耐力赛而对赛车性能进行的改进是有限的。除了对动力系统的可靠性进行了相应改进外,我们也对赛车发动机的冷却系统作了改进,并在2017年参赛车辆的基础上对车身进行了进一步开发。”
光从性能角度来看,自2014年以来,丰田的赛车“不存在什么根本性的可靠性问题,我们本可以在三届勒芒耐力赛中获胜,但这三届比赛中我们却连番失利了,因此必须采取相关措施扭转这一局面。”
丰田TS050赛车采用的是500马力(373kW)的2.4L双涡轮增压直喷V6发动机,前轮由爱信AW提供的牵引电机驱动,后轮由电装公司提供的安装在后桥上的电机驱动。其中,锂离子电池将经由电装公司提供的逆变器转换的电能提供给电机,两个电机加起来共能额外输出500马力的动力。
为了避免将自己赛车具体的性能参数泄漏给竞争对手或是监管者,参赛车队所报出的赛车的性能通常要低于该赛车的实际性能。因此,从丰田给出的整数倍的马力来看,这很明显就是一个保守估计,丰田TS050赛车的实际马力一定高于这个保守值。
中国私人车队与俄罗斯私人车队介绍
对于私人车队而言,最关键的就是要以底盘与发动机为突破口,设计出相比于其它私人车队对手具有一定竞争优势的赛车。同时,在比赛中要尽量跟紧丰田赛车,因为在长达24小时的耐力赛中,丰田赛车极有可能出现故障,这些都为私人车队提供了赶超的机会。
来自瑞士的 Rebellion Racing车队专门邀请了LMP2组别指定的、与勒芒赛事有长期合作关系的Oreca公司来设计打造了R13赛车。来自奥地利的ByKolles Racing车队选用的,是以Lotus Racing车队赛车底盘为基本架构的ENSO CLM P1/01赛车。
来自中国的华信TRSM车队赛车采用的是GinettaG60-LT-P1赛车底盘,而来自美国的Dragonspeed车队,以及来自俄罗斯的SMP Racing车队采用的是由俄罗斯的BR Engineering 公司设计,并由意大利的Dallara 公司负责打造的BR Engineering BR1赛车。
如果这些私人车队采用的底盘还不足以提供足够的竞争优势,那么再来看看这些车队所采用的发动机吧。Rebellion车队与Dragonspeed车队所选用的均是Gibson Technology生产的GL458 4.5-L V8发动机。
ByKolles车队选择搭载的是日产NismoVRX 30A 3L双涡轮增压直喷60度夹角V6发动机,期待着能够恢复该发动机的“昔日辉煌”。该发动机是在日产于2015年发布的GT-R LM Nismo前驱赛车的发动机基础上改造而来的。
SMP Racing车队搭载的是AER公司生产的超过800马力(596kW)输出、最大输出扭矩达590英尺磅(800牛米)以上的双涡轮增压V8发动机。相比之下,华信TRSM车队搭载的是Mecachome公司生产的V364 3.4L反流式气缸单涡轮增压V6发动机。Mecachome公司在自己先前推出的LMP2发动机的基础上加入了直喷技术,并对涡轮增压器、燃烧室、活塞与阀门进行改装后,推出了这款新发动机。不过,虽然大部分发动机部件的生产是在Mecachome公司位于法国的工厂完成的,但引 擎上的阀门却是从Zanzi公司引进的,阀门弹簧是从NHK公司引进的,并且活塞与活塞连杆也是从Pankl公司引进的。
Mecachrome 公司赛车部主管Bruno Engelric 先生表示:“新V6发动机的建造工程开始于两年半以前,当时我们正准备为GP3系列赛以及FIA F2锦标赛打造新的发动机,而之后LMP1项目发起的时候,我们就想,这一发动机正适合勒芒LMP1这样的比赛。”
Gibson Technology公司为Rebllion车队打造的这款GL458 4.5-L V8 LMP1发动机,是在在该公司先前推出的600马力输出(447kW)、最大输出扭矩为410英尺磅(556牛米)的GK428LMP2发动机基础上改造而来的。
虽然Gibson Technology公司没有具体透露这款GL458发动机的功率,但该公司的运营主管John Manchester先生表示,GL458发动机与先前的GK428发动机相比,在性能上已经有了“巨大的提升”,更换了包括曲轴、活塞连杆与活塞在内的约30%的部件。并且Gibson Technology公司在打造这款发动机时也在“发动机减重方面下了大功夫,甚至还对材料作了重大更换。”
Manchester 先生解释说: “这一项目所需的时限较长,这意味着发动机的基本结构设计不可能在短短六个月之内完成”,更何况还要同时确保项目成本目标的实现。
对于所有私人车队以及汽车制造商来说,如何实现较高的成本效益至关重要。预计在FIA当下着手制定的2020版WEC新规中,也有对赛车技术开销方面的限制。
Arguably the pinnacle of auto racing technology, the World Endurance Championship’s 24 Hours of Le Mans is in a period of transition for 2018-19. The FIA sanctioning body has dubbed this period a “super season” for the WEC, during which rules for the 2020 race are being formulated. The goal: attract factory teams back to the world’s premier endurance event, the 86th running of which is set for June 16-17, 2018.
Last year, Porsche and Toyota were the sole factory contenders in the excruciatingly expensive Le Mans Prototype 1 (LMP1) category. After notching its 19th win in the endurance classic, Porsche quit the WEC, citing plans to instead focus on the vastly cheaper battery-electric Formula E series.
“This realignment of motorsport activities for Porsche stems from the direction set out for the company in Porsche Strategy 2025, which will see Porsche develop a combination of pure GT vehicles and fully electric sports cars,” the automaker explained in a statement regarding its decision to make last year its last in WEC racing.
Porsche’s departure left Toyota with no factory-backed rival for this year’s race. In response, the FIA scrambled to formulate less costly (read: not requiring hybrid technology) LMP1 rules that would let private teams challenge Toyota for the win in this prestigious class. The strategy generated a field of eight cars—fielded by five teams—to take on the engineering might of Toyota using chassis and engines available from traditional racing suppliers.
Fuel energy and consumption rules
The interim regulations for 2018/19 give private non-hybrid LMP1 teams 210.9 megajoules (58.6 kW·h) of fuel energy per lap of the 13.62 km (8.47 mi) circuit, compared to the 124.9 MJ (34.7 kW·h) available to the Toyota TS050 Hybrid LMP1-H. Its hybrid-electric drive will add another 8 MJ (2.2 KW·h) per lap.
In addition to limits for total fuel consumption, the FIA also restricts instantaneous fuel flow, limiting the factory hybrid cars to an 80 kg/h rate, compared to 110 kg/h for the non-hybrid privateers. Combustion-engine displacement is unlimited for LMP1, while LMP1-H cars are limited to a maximum displacement of 5.5 L. Finally, the non-hybrid cars are allowed to run 45 kg (99 lb) lighter, with a minimum mass of 833 kg (1836 lb), versus an 878 kg (1936 lb) minimum for Toyota’s hybrids.
Engines are limited to a maximum of four conventional poppet valves and electromagnetic, hydraulic and pneumatic valve-actuation systems are forbidden. Further, variable valve timing and variable valve lift systems are not allowed, but teams are free to employ high-tech plasma, laser and other high-frequency ignition systems.
LMP1 fuel tanks are limited to 75-L (19.8-gal) capacity, which corresponds to the FIA’s 52.9 kg (116.6 lb) fuel limit, while LMP1-H’s fuel capacity is set at 35.2 kg (77.6 lb), corresponding to a 50-L (13.2-gal) fuel tank.
Engine ancillary systems can be driven mechanically from the engine or electrically by dedicated electric motors, but if they are electric, the drive cannot also be connected to the engine mechanically. Power brakes are prohibited and calipers must be of aluminum and contain a maximum of six pistons. Brake rotor material is unrestricted, but diameter is limited to 15 in (37.5 cm).
The overall intent is to give lower-budget privateer LMP1 teams a glimpse of opportunity to unseat the Toyota “works” juggernaut. And over the course of 24 hours, it is entirely possible that could happen, as Toyota saw in 2016 when, while leading on the last lap, a breakdown handed victory to Porsche.
"Our obvious target is delivering a significant step-up compared to the past, but honestly, we are raising our game,” said ByKolles team principal Manfredi Ravetto. “We are proud of being manufacturers in LMP1, which is the ideal stage for our constantly-growing structure and we are grateful to ACO and FIA for organizing and promoting such a championship, nowadays second to none in the world.”
But in pre-season testing—and in the 2018 season-opening race at the 6 Hours of Spa-Francorchamps—the Toyota TS050 Hybrids enjoyed a decisive advantage over the non-hybrid privateers, even while they probably were sandbagging to avoid any further handicapping for the Le Mans race. The Toyota TS050s finished first and second at Spa, with a race pace of 1:57.805, which was 1.2 seconds faster per lap than the third-place Rebellion R13 non-hybrid. In qualifying, the gap between the Toyota’s and the rest of the field was 2 seconds, before the pole-winning TS050 had its time disallowed for an administrative mistake regarding replacement of a fuel-flow limiter.
Inside Toyota’s TS050
Toyota is aiming to make Le Mans history in 2018, with a goal of running a record distance to demonstrate the TS050’s speed. Indeed, in 2017 the car already set a record lap time, while using 35% less fuel compared to the team's 2012 car.
Team engineers note that they have made “small but productive” upgrades to the TS050’s aerodynamics compared to last year and have added a Gentex-supplied rear-view camera to help spot overtaking cars. Rear-view cameras are a new requirement for 2018, but probably not be terribly important for the Toyotas unless they break down. The team says it also has modified the car’s 1,000-hp (746-kW) hybrid-electric powertrain for improved reliability.
"Unlike previous years, the upgrades on our 2018 car are limited,” stated Pascal Vasselon, Toyota Gazoo Racing technical director. “In addition to reliability improvements on the powertrain, we updated the cooling system and developed the bodywork within our 2017 homologation.”
In terms of outright performance, Toyota has since 2014 had “a car fast enough to win Le Mans on three occasions, with no fundamental reliability issues,” Vasselon asserted. “Nevertheless, we failed every time to win so we had to do something about it.”
The TS050 carries over its twin-turbocharged, direct-injected 2.4-L gasoline V6 producing an announced 500 hp (373 kW) and supplemented by an Aisin AW-supplied traction motor driving the car’s front wheels and a Denso e-motor on the rear axle. They combine for an additional 500 official horsepower, with power routed from the lithium-ion battery pack through a Denso inverter.
Race teams habitually underrate their car’s performance to avoid tipping their hands to competitors or regulators—the conveniently round numbers Toyota claims seem a sure sign of that conservative approach, so the TS050’s true power output surely is higher.
Chinese and Russian privateers
For the privateers, the challenge is to identify the most competitive possibilities from the available chassis and engines to produce cars that will beat their fellow privateers, while keeping close enough to Toyota to be able to capitalize on any problems they might encounter during the long 24-hour race.
For chassis, Switzerland’s Rebellion Racing commissioned LMP2 constructor and longtime Le Mans stalwart Oreca to create its R13 racecar. Austria’s ByKolles Racing runs a Lotus Racing-designed chassis that the team calls the ENSO CLM P1/01.
The Chinese CEFC TRSM Racing team fields a Ginetta G60-LT-P1 chassis, while both America’s Dragonspeed and Russia’s SMP Racing employ the BR Engineering BR1, a car designed by Russia’s BR Engineering and constructed by Italy’s Dallara.
If these various chassis don’t provide enough variety of potential, consider the engines the teams are using. Rebellion and Dragonspeed both chose Gibson Technology’s GL458 4.5-L V8. ByKolles is attempting to salvage some glory for the Nissan Nismo VRX 30A, a twin-turbo, direct-injected gasoline 3.0-L, 60-degree V6 that originated in Nissan’s 2015 front-drive GT-R LM Nismo car.
SMP Racing’s entry is fitted with an AER-supplied twin-turbo V8 producing more than 800 hp (596 kW) and 590 lb·ft (800 N·m). By comparison, the CEFC TRSM team uses a Mecachome V364 3.4-L reverse-flow, single-turbo V6. It’s a development of the company’s LMP2 engine, updated with direct injection and a modified turbocharger, combustion chamber, pistons and valves. Though Mecachrome produces most of the engine components at its factory in France, the valves are sourced from Zanzi, valve springs from NHK and Pankl provides the pistons and connecting rods.
“The project for this new V6 engine started about two and a half years ago,” noted Bruno Engelric, Mecachrome’s Motorsport Director. “We agreed to build new engines for the GP3 Series and FIA Formula 2 Championship, so when the LMP1 program was launched, it was obvious that this engine would be the perfect basis.”
Gibson Technology’s rival GL458 4.5-L V8 LMP1 engine for Rebellion is based on the company’s 600-hp (447-kW), 410-lb·ft (556 N·m) GK428 LMP2 power unit. Gibson won’t specify the GL458’s output, but John Manchester, Gibson Technology’s Operations Director, said it’s a “significant” increase over the GK428’s rating. The LMP1 engine (based on the LMP2) employs about 30% different parts, including the crankshaft, rods and pistons. “We put in a lot of work on weight reduction, including some significant materials changes,” he said.
“The timeframes required meant that a ‘ground up’ design could not have been achieved in under six months,” Manchester explained, while meeting cost targets.
Among the privateers, cost-effectiveness is all important. And it is significant to manufacturers as well. Expect to see limits on costly technologies when the FIA issues rules for the 2020 WEC season.
Author: Dan Carney
Source: SAE Automotive Engineering Magazine
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