cars news 10: Touring the 2017 Acura NSX’s Ohio Factory

America has a new homegrown supercar. Birthers take note: Japanese brand Acura’s NSX supercar is built here at the Performance Manufacturing Center (PMC) in central Ohio, as is its engine. Come along for a tour of this high-tech, low-volume birthplace of not only an exotic performance car but also some manufacturing techniques that are expected to bubble up to Honda’s volume plants. The mantra is “8 to 800.” If it can work building eight cars a day (the anticipated peak NSX production rate), let’s see if it can be adapted for 800. (That’s the daily output rate of the nearby Marysville Auto Plant next door, which builds Honda Accords and Acura TLXs.) The plant has applied for 12 patents on various tools and processes used here. Let’s check out a few of them.

MIG Welding

The NSX’s aluminum space frame boasts several unique features. Like most, it’s mostly made up of extrusions welded to castings and to each other. These parts are mostly joined by MIG welding (metal inert gas), which can generate enough heat to distort the parts. Some companies account for this by machining all the critical suspension and powertrain mounting points after the space frame is completed. Honda machines its thinner casting before assembly and controls for dimensional accuracy by using faster robotic MIG welders shown here and programming them to alternately weld on opposite sides of a part so that any heat distortion in one direction is corrected with heat distortion in the opposite direction. Pretty clever. And the robots in four different cells like this one can be programmed to perform most any of the space frame welds just by moving in a different giant black rotisserie jig like the one you see here. They have racks of them.

Weld Inspection Ablation Casting

Every weld is visually inspected and repaired or rejected as necessary before the space frame advances. Also worth noting is the large casting you see here, which will support the left rear suspension and powertrain. The NSX uses six that constitute the world’s first automotive application of ablation casting. Basically, the sand molds are water soluble so that soon after the molten aluminum is poured into them, water jets “ablate” or blast away the sand, cooling the metal rapidly and directionally. This produces a finer, stronger microstructure that allows for lighter, thin-wall castings that absorb crash energy better.

Roller Hemming

This clever robot is using rollers to fold the hem of the outer panel over the flange of the inner panel on this engine-cover hatch panel. This is Honda’s first North American application of this novel process. Resistance spot welding is also used in just a few places to join panels on the hood and hatch.

Finished Space Framing

It takes about 10 hours to weld all the subassemblies into a finished space frame like this one, which has also had three ultra-high-strength steel (UHSS) components bolted on. The black primed windshield header is one, and the two A-pillar/roof rails are the others. Achieving identical strength from aluminum parts would have resulted in much thicker pillars. These start out as straight UHSS tubes that are heated up and then bent and quenched into the three-dimensional ultra-rigid gray-primed pieces you see here.

CMM Quality Check

The glass-walled Quality Confirmation Center is in the center of the PMC. Currently all pre-production space frames are passing through here to have their dimensional accuracy measured with these coordinate-measuring machines. Any inconsistencies are used to go back and better dial in the jigs and/or reprogram the welders. Once full production starts, representative samples will likely be checked.

Paint Dip

The finished space frame then heads into a series of four tanks. The far left one shown here has a caustic cleanser in it to remove oils and other contaminants. Then it gets dunked in two water baths before heading into the innovative new zirconium dip tank on the right. This electrically applied primer is unique in that it doesn’t produce the sludge that zinc-phosphate materials currently in wide use do. The sludge can stick to the body and ultimately needs to be landfilled. This technology will definitely achieve widespread use quite soon. All the naked aluminum parts come out black, but no new primer sticks to the steel parts that were already primed. Right next to the zirconium tank are two oven cells that bake the primer for 50 minutes at temperatures of up to 340 degrees F.

Sealing Jig

The cured space frame then gets mounted to this patent-pending rotisserie gizmo that allows a single operator to comfortably reach every joint and hole in need of sealing against noise and dust. This process takes about two hours, after which it goes into another oven to bake for 30 minutes.

Sealing Check

The cured sealant is then visually checked using this clever projector “slide show” that alternately illuminates every area that should have white sealer on it.

Body Paint

The space frame stays black, so all the body panels ride through the paint shop on a carrier like this. The panels are made of either aluminum or one of four types of plastic/fiberglass (SMC, TPO, ABS, G-Loy). Robots do most of the work, applying up to five coats of base and four coats of clear. The robots stand still as the carrier moves. Humans check their work and make fixes where necessary. The black radiator grilles are all hand-painted. The parts spend two days in this process with several 45-minute low-temperature baking cycles sprinkled in.

Final Assembly

While the body panels are finishing their time in the paint shop, the space frame starts its roughly 14-hour trip through 22 stations, spending about 62 minutes in each. The only robot on this line applies the adhesive used to bond the painted door surrounds, the roof panel, trunk outer panel, and all the fixed glass. The line starts parallel to the glassed-in paint shop (which would be just off the left frame of this photo) passing from left to right at the far back of this photo, then turning around for engine installation and a right-to-left pass up the middle aisle. The red cars in the foreground are shown in their last few stops. It’s only here that most of the body panels get installed. That way they never get a chance to get scratched or scuffed.

Engine Marriage

Everyone’s favorite stop on any assembly line is the “engine marriage” station. Here the space frame and engine are both meticulously leveled then the body is lowered and the engine and its cradle raised to meet. The mounting bolts—like all bolts on the line—are hand-started and machine torqued to spec.

Alignment

The finished car gets its alignment checked by an operator riding on this patent-pending chair, which rolls along on elevated tracks and swivels to allow the operator to comfortably make all the alignment adjustments.

Alignment Reflector

Usually the reflectors that mount to the wheel to measure wheel alignment grab the aluminum rim. But this can damage a wheel, so Acura patented this setup that mounts quite securely to the center of each wheel.

Dyno Test

Each car gets a brief dyno run to verify the functionality of critical systems such as the turbochargers, speedometer, and other key electric and electronic functions. In another patented procedure, the brakes are tested for force applied at precisely 55mm of pedal travel. This permits verification not only of brake function but also of pedal feel. It should be noted that at the end of the engine assembly process in nearby Anna, Ohio, and at the end of the transmission assembly in Hamamatsu, Japan, the powertrain components are extensively broken in. The engine runs for an hour at varying speeds and loads—the equivalent of 150 miles of break-in driving. This allows Acura to certify that the NSX is track-ready from odometer-mile zero when the customer takes delivery.

Shake and Paint Check

At the penultimate stop on the NSX production line, a technician inside the vehicle listens for buzz/squeak/rattle issues as those red and black pads shake the four corners of the suspension. The LED lighting also helps them check for imperfections or damage to the paint that might have occurred in the short time since the body panels were attached. In the final stop, the bay visible in front of the car, it gets pelted with high-pressure water for a leak check. This water, incidentally, is reclaimed from the primer rinse tanks, reverse-osmosis filtering ensuring a spot-free rinse. From there the cars drive into a covered warehouse to await covered shipment to the customer’s dealership.

More on the Acura NSX here: