Programs for new re-engineered vehicles pose a great challenge for the engineers and other professionals assigned to them: load the vehicle with more advanced technology, consumer-friendly amenities, and safety features required to meet stringent requirements, all while trimming weight from any area necessary to maintain—or ideally decrease—overall weight compared to the previous generation. The 2016 Honda Pilot development team, faced with said challenge, succeeded brilliantly.
The new three-row SUV is 289 lb (131 kg) lighter—the previous Pilot Touring weighed 4632 lb (2101 kg) vs. the new Pilot Elite, which includes more features but weighs 4343 lb (1970 kg)—while recently earning a 2015 Top Safety Pick+ rating from the Insurance Institute for Highway Safety (IIHS).
The 2016 Pilot adopts the second generation of Honda’s Advanced Compatibility Engineering (ACE) body structure along with a new “3-bone” underbody frame design and new hot-stamped ultra-high strength steel (UHSS) door rings.
Located under the front floor of the Pilot, the 3-bone structure improves impact load management, directing energy around the passenger cabin in the event of a frontal collision. The structure creates three different load pathways that channel collision energy. One channels collision forces from the front of the vehicle directly underneath the passenger cabin; the other two channel collision forces under the vehicle’s left and right side frames. The structure saves 61 lb (28 kg).
According to Marc Ernst, Pilot Development Leader, the Pilot platform is more than 80% similar to that of the Acura MDX. And similar to the MDX, the new Pilot employs multiple lightweight, high-strength materials for its construction, including seven different grades of steel; an aluminum hood and front bumper-reinforcement beam; and a cast-magnesium steering hanger beam. In total, 61.5% of the body structure is composed of advanced materials, most notably 21.3% of UHSS ranging from 980 to 1500 MPa, which is used for the front door outer stiffener rings.
In addition to enhanced crash protection, a result of this multi-material structure is 25% more torsional rigidity than the previous-generation SUV, as well as 67% better mount rigidity. Another benefit of using UHSS is improved visibility due to narrower A- and B-pillars. Total outward visibility for the driver improves from 271.4° on the previous model to 283.5° on the 2016 Pilot.
The SUV is 3.5 in (89 mm) longer, at 194.5 in (4940 mm), with 1.75 in (44 mm) of that increase in the wheelbase. A 1-in (25-mm) lower overall vehicle height and a subtly narrower width give a sleeker look and aid aerodynamics. Compared to the previous Pilot, specific aero refinements include a 1.93% reduction in frontal area, a full-width air dam, and underbody details such as air strakes and covers. CFD simulations show a 10% reduction in coefficient of drag (CdA) for the new model.
Chassis and powertrain refinements
The Pilot’s new front strut suspension includes the first use of Amplitude Reactive Dampers. Smaller driveshaft angles help to mitigate torque steer, and a reduced center offset reduces steering wheel vibrations. At the rear is a multi-link design with a tubular stabilizer bar. Compared to the previous Pilot, where the setup transmitted suspension loads to the vehicle’s rear wheelhouse, the new setup transmits suspension loads to the more rigid body side frame, which allows for more aggressive tuning of suspension bushings, according to Ernst. The elimination of the forward trailing arm on the previous Pilot rear suspension allows for a 1.4-in (36-mm) lower rear floor.
A 16.0:1 steering ratio for the new Pilot is about 10% quicker than the previous model’s steering, which complements the functionality of the torque-vectoring rear axle on AWD models. The available new Intelligent Variable Torque Management (i-VTM4) AWD system with an electronically controlled rear differential and dynamic torque vectoring capabilities aids both traction and cornering performance. Other benefits include 46% faster all-wheel response time and 20% greater torque capacity. The new system, which is Honda’s first U.S. application of torque vectoring, is 22 lb (10 kg) lighter than the previous one, with reduced drag.
Powering the 2016 Pilot is a 3.5-L direct-injected i-VTEC V6 engine with Variable Cylinder Management cylinder deactivation. The new engine is mated to one of two new transmissions: a 6-speed automatic (6AT) for LX, EX, and EX-L trims, and 9-speed automatic (9AT) for Touring and Elite models. Models with the 9AT also have a new Idle-Stop capability to enhance fuel efficiency.
The EarthDreams series V6 is rated at 280 peak hp (209 kW) and 262 lb·ft (355 N·m) peak torque—increases of 30 hp (22 kW) and 9 lb·ft (12 N·m) over the previous model. EPA fuel-economy ratings (city/highway/combined) are up across all trim levels. The 2WD model with 9AT gets 20/27/23 mpg.
The new Pilot was designed and developed by Honda R&D Americas, Inc., in Los Angeles and Ohio, and is manufactured by Honda Mfg. Alabama, Inc. in Lincoln, AL.
Honda’s NPD process
With nine trim levels and a high level of feature content, the 2016 Pilot could have been a daunting challenge for Honda associates who assemble the all-new vehicle in Lincoln, AL, as well as for the program’s systems suppliers.
“All this [new] content created a tremendous amount of build complexity,” noted Jeff Tomko, President of Honda of Alabama Manufacturing. He said during early planning discussions Honda R&D engineers realized the need for more flexible processes that made the larger vehicles easier to assemble without sacrificing quality.
The solution was NPD (No Prototype Development), a digital product development-and-manufacturing process that makes its full-scale debut on the new Pilot. NPD aims to ultimately eliminate all physical prototypes prior to their requirement in final vehicle-crash certification. The “virtual build” concept has long been an industry aspiration, of course, and Honda has been working up its NPD systematically, employing it first on some aspects of the 2015 Acura TLX sedan program.
“The key to NPD is close collaboration between our R&D engineers and manufacturing teams,” Tomko told Automotive Engineering. Playing a vital supporting role is Dassault Systemes’ comprehensive suite of 3D applications—CATIA (design/engineering), DELMIA (manufacturing operations), SIMULIA (FEA and simulation), and 3DEXCITE (real-time visualization)—that are used by Honda. Working for the first time without hard prototypes—previously R&D would build about 100 white bodies per program, for example—the R&D-and-plant-floor teams employed a new training strategy, with each department establishing a “Top Gun” go-to expert for rapid leveraging of know-how.
As a result, design engineers gained first-hand experience with Pilot production challenges during early trials in the plant, rather than at the R&D center. An important time-saver was Honda’s expanded use of 3D printing to support process development. Examples included creation of a special line-side ergonomic lifting device for installing the Pilot’s new electric power-steering motor unit; a transparent IP cover that served as a troubleshooting tool; and a center console 3D-printed to determine ease of assembly.Continue reading »