"In place of the steel frame on the conventional C6, GM is substituting an almost identical aluminum spaceframe, thereby reducing mass by over 30%. The frame is produced for GM by the Structural Solutions Group, Dana Corp. Although it might seem like a simple substitution, according to William Kroppe, director, product engineering, at Dana's Structural Solutions, transforming a spot-welded steel frame into an aluminum structure held together by MIG and laser welds and self-piercing rivets while precisely maintaining the same dimensions as the original led Dana to a couple of industry firsts. Kroppe points out that while many automakers have produced aluminum-bodied vehicles that use panels on the order of 1-mm thick, few have worked with the 3-mm+ thicknesses needed for an aluminum frame.
The Corvette Z06 aluminum spaceframe is a smorgasbord of aluminum castings, extrusions and stamped panels. Dana uses 14.2 meters of laser welds and 238 self-piercing rivets to assemble the frame. Hydroformed side rails come from GM's Metal Center in Pontiac, MI. The total part count for each frame (excluding fasteners) is 90, which is lower than that of its steel counterpart.
Dana has carved out a small cellular assembly area for the Z06 in its manufacturing facility in Hopkinsville, KY, that is otherwise dedicated to producing serious volumes of stamped and spot-welded steel frames. (Annual volume for the Z06 is projected at 7,000 units.) "Compared to the other frames we make in that plant, this is Swiss watch work," says Kroppe. To prove the point, he describes how the aluminum castings that provide the attachment points for the suspension components are CNC machined with a precision that exceeds steel frame fabrication techniques. To achieve the highest degree of dimensional accuracy, Dana found it best to assemble the body first and then machine it using a Tricept robot from ABB."
- autofieldguide.com
http://www.dana.com/
http://www.abb.com/
12. Magnesium steering-column bracket
17. Aluminum brake and clutch pedals
18. Hydroformed lower instrument-panel tie bar
20. 370mm 3-spoke steering wheel
15. Aluminum unequal-length control-arm suspension
27. Short-throw 6-speed manual transmission, rear-mounted transmission and axle collers, larger rung gear rear axle
2. High-strength bumper beam
13. 3-inch stainless-steel exhaust with polished 4-inch tips and Pierburg valves
15. Aluminum unequal-length control-arm suspension
4. High-strength bumper beam
14. 7.0 liter LS7 V-8 engine, 505 hp, 427 cubic inches, titanium valves and connecting rods
7. Aluminum wheels, 9.5 x 18 front
8. 275/35ZR-18 Goodyear Eagle F1 Supercar EMT front tires
9. 14-inch cross-drilled rotors with 6-piston calipers with individual pads
1. 13.4-inch cross-drilled rotors with 4-piston calipers with individual pads
6. Aluminum wheels, 12.0 x 19 rear
16. 325/30ZR-19 Goodyear Eagle F1 Supercar EMT rear tires
The following information and pictures are from motortrend.com:
1. Splitter and 30-percent-larger grille opening make Z06 a front breather; base car is a bottom breather.
2. Intake air enters through new nostril.
3. Black fender lips at the leading edge of the front wheel openings direct air around the wide tires. Generous radius at trailing edge of fender liner smooths airflow, deflects stone damage.
4. Carbon-fiber front fenders widened slightly and incorporate larger functional air exhaust scoop. Must be clamped to a painting fixture, or the sprayers blow them away.
5. Hatchback body style weighs 22 pounds more than the previous Z06's notchback, but greatly improves aerodynamics. Lightweight Plexiglas considered for the hatch flunked GM's ultraviolet stability and scratch-resistance tests.
6. Rear SMC quarter panels widened by 1.5 inches each to clear wheels that are two inches wider than the base car's.
7. Tall Gurney-lip ducktail spoiler reduces lift.
1. Hydroformed structural side rails are geometrically identical to their steel counterparts. Remaining aluminum castings, stampings, and sheets are attached via metal-inert gas welding, laser welding, and riveting. Dana Corp. builds the structure.
2. Six-piston calipers chomp on 14.0 by 1.3-inch rotors in front, four-piston calipers and 13.4 by 1.0-inch rotors suffice in back. Ceramic brakes were planned for the Z06, but won't be implemented until costs fall sufficiently to market them as a $4000 option.
3. Magnesium roof structure from coupe's removable panel gets bolted in permanently. Maintaining the desired chassis rigidity with a removable roof would've required 44 pounds of added structure.
4. Balsa-wood core floor panels are sandwiched between layers of carbon fiber instead of fiberglass, adding strength and reducing weight.
5. Springs and bars stiffened all around. Sachs monotube shocks fitted (the magnetic shock fluid can't withstand severe track duty).
6. Exhaust flows through short tubular header pipes into a large four-into-one collector chamber and then to a high-flow catalyst through three-inch pipes to two giant mufflers. Each has a mechanical flap that opens above 3500 rpm near wide-open throttle for straight-through flow. Result: 38-percent-less back pressure than in LS2.
Items that add weight: pounds
-Upgraded brakes 27.6
-Dry-sump, extra oil, oil cooler 23.1
Three-inch exhaust and valved mufflers 11.7
Larger differential with cooling circuit 11.0
Rear-mounted battery (cables and bracket) 8.8
Larger wheels and run-flat tires 6.2
Items that subtract weight:
Aluminum chassis structure 136.7
Reduced interior content*
*(electric seat bolsters, six-way passenger-seat adjustment, acoustic damping material) 33.0
Magnesium engine cradle 11.9
Removable roof hardware 6.6
Carbon-balsa floor panels 5.3
Carbon-fiber front fender liners 2.2