Topic: The Solstice build process! (A look back in time)

[GXPinKC]

Wilmington plant manager, Dennis Dougherty led one of the industry's most unusual and challenging vehicle launches and builds.  Here's that story in his own words as reported in "The Pontiac Solstice Book" by Gary Witzenburg.

"The Solstice launch was a challenge for everyone because of the targets we put out there:  build a brand-new car on a brand-new platform, do it fast, and break all the rules.  That meant the engineers weren't following the milestone charts that say you have to finish this before you can start that.  There was a lot of parallel work...they got to 70%-80% of the solution for one task, then they pulled the trigger on the next one. 

Lutz said, "Get this showcar into production, do it justas it is, and do it fast"...not the normal way we'd bring in a whole new program.  A lot of things are completely different about this car.  The dominant lower structure is something only the Corvette had used before.  We had to do some really out-of-the-box thinking and, because this is an affordable, fun car, we had to  do things more frugally than on the Corvette.  And ws were putting it into the plant while we were still building the last of the Saturn L-Series. 

The way this car is designed means we have to build it unlike anything we've ever built before.  For example, the hood is hinged at the front, the deck at the rear, and since any dimensional variations are greatest at the very ends of a vehicle, that creates more of a challenge for installation and fit than a traditional build.  We had to come up with new exterior panel installation techniques and tooling to accommodate that and still get world-class fits.

You have to change how you think about where to start the build and how to assemble the car.  It's nothing like a traditional vehicle with structure all around the passenger compartment.  We start with the rear quarter, then add the doors, then the hood and deck, and we put the front fenders on last.  All the car's strength comes from the rails in the central tunnel, so we have to get down to those rails with support for everything higher up in the body.  Also because the structure is down in the tunnel, integration of the top, getting the fits aligned and dealing with how the decklid opens, shuts and seals...those were real challenges.

We didn't know all those things going in, so we designed a lot of stuff on the fly.  Some ideas didn't work, some did.  The bad ones we threw out; the good ones we productionized so we could run them day in, day out.

To get the car into production fast, we didn't spend a lot of time developing automated cells to weld the body.  We're heavily into manual MIG-welding.  You
normally try to get your welding in the 98% automated range, but that didn't fit on our standard lines because the car had such a different architecture.  So
what's the fastest way?  Let's get the tooling bucks in here, figure out how it goes together, manually MIG weld, manually shuttle it and see how fast we can get this car to market.

We pretty much build the whole car here, without a lot of modules, we weld the structure together.  We bring in the raw stampings and weld and hem the exterior sheetmetal.  We make the complete door assemblies, weld together the inner and outer skins and reinforcements.  We dress the engines and powertreain and do the complete painting operation.

In the Bodyshop, we move the car by hand from weld fixture to weld fixture useing a sophisticated version of an overhead chain hoist.  When a welding team completes its sequence, they hit their buttons to unlatch the body, then this overhead hoist carries down, clamps on and picks it up.  Then it's manually advanced to the next fixture and dropped down.

Also different is that all the exterior skins go on in general assembly.  In a converntional build, most body panels go on in the bodyshop prior to paint.  Normally, in general assembly,  you put in the wiring, the glass, the latches and hardware, then yhou put in the softer stuff--door pads, carpets, seats and instrument panel.  Then, after you get the body all done, it hoes to chassis, and that's where you put in your powertrain and suspension. 

We do the complete opposite here on the Solstice and Sky.  We start with the differential and suspension, then we stuff in the engine and transmission with all the auxilliaries, the air conditioning and electrical tunnel with the transmission as we load it.  The teams came up with a little rollerskate that they clamp to the top of the transmission that guides it back as it slides in.

Anlother unusual thing is how we bond the outer skins to the structure,  especially the rear trunk tub, the rear quarters and the other rear-end attachmnents.  We use two different types of adhesive: a urethane similar to windshield sealer, and a two-part epoxy.  We frame up the quarter panels and apply urethane.  This gives a continuous seam hold.  Then we put on "dimensional" epoxy dollops that hold the part exactly in place while the urethane cures--sort of like putting on dimensional welds in a robotic framing station.  And this is all done after paint.  The lower structure gets painted and sealed separately from  the exterior metal.  The exterior metal goes to paint on a separate paint buck, then comes down to general assembly.

To deal with any issues in the field after we launched the Solstice, we set up a very quick call back systrem.  I had any dinormation that came back from our dealers by eight the next morning.  And we had a very fast turnaround process to make sure we could get fixes into our production line immediately.  We did the same thing with the Sky.

Most things were minor.  For example, when you open the release handle on our convertible top, you have to leave it open.  If you re-close the handle, then fold the top into the trunk, the latch interferes with the decklid striker, and that can bend it.  That was actually our main concern for a while.  Working with our sales department, we explained the process to our customers and incorporated instructions into our Get to Know You pamphlet that comes with every vehicle.

We've gotten some questions about the normal characteristics of the car: a little gear rattle and some noise from the differential.  We tell our dealers to explain to the customer that when you have a limited-slip differential, you will get that type of noise.

There was a pretty good plan going in on how to build this car, but it needed more than a plan.  It was a real team effort, with good ideas from everyone who touched the car.  I'm really, really impressed with the team members here.  With a new launch, it's easy to get discouraged with the problems that come up, but everyone remained extremely excited.  There were very high levels of contribution on problem solving, and the combination of peoples' ideas took this car from good to great.  It really was inspiring to see the whole organization pull together like that." [End Quote]

[GXPinKC]

Well, this thread was my 4th post to the forum back on December 14Th after joining on the 12Th, and since it has not had any replies, I will do the honors.  I still find the history of our little creature to be quite fascinating and in a word incredible.  So, I will continue with some more.  Please hold on and give a look, if so inclined and add to the discussion if you wish.

  "The Pontiac Solstice Book".  "The overriding priority, " says the project's original chief engineer, Doug Parks, "was to build a production version of the showcar within our given time-frame.  We could have used different processes for higher volume cars, because if you're going to dump a half billion dollars into a mass-produced car, you check a few more boxes.  We didn't have those boxes.  We moved very quickly and used our engineering judgement and common sense in areas where sometimes you spend more time taking more steps."

"We did a lot of math-based virtual engineering.  The car was designed, tested and crashed in the computer, and we built hardware mules to verify that data.  If we'd had any real crashworthiness problems, we would have been a year late, but none of that happened.  The fact that we pulled this car off in a little over two years is due mainly to the overriding passion to clone the showcar as rapidly as we could.  And that's exactly what we did:  We built the showcar."

Jim Queen compares this program to the Corvette.  "The car was something we were all in love with.  It resonated well with the press and the public, and we maintained the styling of the concept vehicle, with just minor modifications."

"When we designed the naturally aspirated 2.4 liter Ecotec, this one (GXP) was already on the radar screen," Groff explains, "so the block was improved substantially and designed to accommodate the turbo.  We call it our 'Gen II' block, and it'll eventually be common worldwide.  We went to a semi-permanent-mold aluminum head and dis a lot of finite-element analysis to strengthen it.  The pistons are subject to a lot of heat flux due to the high power density, so we went to what's called a 'salt-core' piston with oil galleys and oil-jet cooling."

"The unique dual-scroll turbocharger, which keeps exhaust pulses from cylinders #1 and #4 separate from those of cylinders #2 and #3 until they enter the turbine housing, delivers up to 20 psi of boost with nearly instant response."

"The dual-cam phasing also adjusts valve overlap to increase the turbo's response at low rpm.  Other features that set this engine apart include its relatively high 9.2:1 compression ratio, steel crankshaft, forged connecting rods, sodium-filled exhaust valves, stainless-steel exhaust manifold and the cast-aluminum, jet-spray-cooled, oil-galley pistons."

"Vehicle performance manager Dean Perelli says the GXP benefits from the basic Solstice's highly capable structure and chassis.  Most components--the five speed manual transmission from the Colorado/Canyon/Hummer H3 mid-sized truck, the driveshaft and differential from the Cadillac CTS/STS/srx heavy-duty to begin with. 

"The 260-bhp Ecotec turbo didn't exist when we started," notes engineer Perelli, "and this is the first application, so the challenge came in developing a brand-new engine and integrating it into the Solstice."

"We wanted to get the car to market very fast, and there was a blank sheet of paper".  It took four months to have the Solstice on its wheels and running for the North American International Auto Show in Detroit in January 2002.  The roadster was not finished until the night before the International Auto Show.

One thing that the engineers wanted was the hood that opened forward like a Jaguar XKE, and other cars of that era.

Hydroforming, the new anel-shaping process, had never been used in volume production. 

The "Proof of Concept" vehicle #1 was completed by May 2003.  The first Mules were built in October 2003.

A typical development and validation time frame incorporated two weather seasons, two summers and two winters, for sufficient vehicle evaluation, development and validation of prototype and production parts.  The Solstice program did not have that luxury, just one shot at it!

The SIDI GXP Turbo technology was a joint venture among General Motors subsidiaries in Germany, Sweden, and Italy.  They all collaborated on the vehicle, adding a new clutch system, a dual-mass flywheel to handle the added torque, re-tuned the suspension with larger stabilizer bars and re-calibrated springs, shocks, and control arm bushings, and of course added electronic stability control. 

Wilmington was awarded the job of building the Solstice.  The Wilmington Plant was built in 1946.  A third shift was added in January of 2006.  The line rate at the plant on the Solstice is 7 cars per hour, so to hit the target of 1256 cars per day, three shifts were needed.

At the Wilmington plant, sheetmetal stampings get painted before their installed on the car. 

A new architecture was created for the Solstice and it was called the Kappa, which was a more affordable Corvette inner structure with full-length, hydroformed side rails, and a galvanized steel central tunnel.

A stamped unibody structure, which requires big, expensive dies and press lines can stamp out 200,000 units a year.  That is the rate at which most volume automaker's build their cars. 

The Solstice total investment to put on the road was no more than 200 million.  That compares to 500 million for a typical new vehicle program. 

Some shared components:

Ecotec Engine:  Pontiac G6, Chevrolet HHR/Cobalt, Saturn Ion

Manual Transmission:  Cadillac SRX/STS/CTS

Parking Brake:  Saturn L-Series

Steering Wheel:  Pontiac Torrent

Steering Column:  Chevrolet Cobalt

Seat Frame:  Opal Corsa

Passenger-side airbag:  Chevrolet Cobalt

Heating, Ventilation system:  Hummer H3

Ventilation outlets:  Fiat Barchetta

Interior storage bin:  Cadillac XLR

Front fog lamps:  Pontiac Grand Prix

Backup Lamps:  GMC Envoy

Exterior door handles:  Chevrolet Cobalt

"[End Quote]"

Well, maybe you have seen it before, but as a part of history have posted again.  I recommend that you walk, don't run to purchase:
"The Pontiac Solstice Book" by Gary Witzenburg.