2004 Z06 Corvette Commemorative Reunion Aug 29, 2014

Corvette Z06 LeMans Commemorative Edition

For the 2004 model year, a 24 Hours of Le Mans Commemorative Edition of the Z06 (dubbed the Z16 after its RPO code) was offered in celebration of the C5-R "1-2" in-class finishes at Le Mans. The option package consisted of a special paint color ("Le Mans Blue Metallic"); wide, silver-and-red stripes optionally applied down the center of the car; a carbon fiber hood (saving an additional 10 pounds of weight); special commemorative badging and headrest embroidery; and brightly polished wheel rims (a first on the Z06) with unique centercaps. Though not as outwardly apparent, the Z16 also received shock damping tuning for improved handling. The Z16 was the most produced Z06 in 2004 totaling 2025 units; of that number, 325 went overseas, leaving North America with approximately 1700.

Starting with the most structurally rigid body style offered, the hardtop or "fixed roof coupé" (FRC), an uprated FE4 suspension, larger wheel rims and tires, revised gearing ratios, and functional brake cooling ducts became part of the total package. The Z06 is 38 pounds lighter than a standard C5 hardtop thanks to weight-saving measures such as a titanium exhaust, thinner glass, lighter wheel rims, non-EMT tires, reduced sound proofing, fixed rear radio aerial, and a lighter battery.

In 2001, 5,773 Z06s were manufactured in five different colors: Quicksilver, Speedway White, Black, Torch Red, and Millennium Yellow. The most popular color in 2001 was Black while Speedway White was optioned in the fewest Z06s. Z06 sales increased by over 40 percent in 2002. Millennium Yellow, Torch Red, Quicksilver, and Black were held over from 2001. Electron Blue replaced Speedway White. Black was still the most popular color with Millennium Yellow being the least favorite. Color offerings remained the same in 2003; however, while Black was still the most popular selection, Quicksilver became the least popular in a model year that saw 8,635 Z06s produced. With expectations of the C6 generation, the final year of the C5 Z06 produced only 5,683 vehicles. Torch Red, Millennium Yellow, and Black were held over for the end of the fifth generation. Le Mans blue replaced Electron Blue and Machine Silver replaced Quicksilver. Le Mans Blue was the most popular color by almost two to one over the next most popular color - black.
In all, 28,388 Z06s had been produced during the C5 generation representing approximately one out of every five corvettes manufactured during the 2001 - 2004 model years.

LS 6 Engine

The Z06 uses a high-output version of the LS1 small-block engine. The name was changed to LS6 after substantial modifications. The new engine powerplant produces about 12% more power than the LS1 and looks identical in external appearance save for the red engine covers. The LS6 produces 405 horsepower (302 kW) at 6000 rpm, and 400 lb·ft (542 N·m) at 4800 rpm. The engine redlines at 6500 rpm (versus the LS1's 6000 rpm redline).
The LS6 utilizes an aluminum block which has been modified to allow greater bay-to-bay breathing. Typically the LS1 engine allows too much air in its crankcase developing into parasitic loss of power. The LS6 relieves this unwanted pressure translating into a removal of parasitic loss thus gaining more power.

• New Pistons

The LS6 utilizes modified versions of the LS1 pistons. The new pistons are made from M142 aluminum alloy which has proved to be stronger and more durable than the material used in the LS1. The pistons have been reshaped to have a slight barrel shape difficult to see for the normal onlooker. The new design also reduces internal mechanical noise because of its increased efficiency.

• Increased Compression

The LS6 cylinder heads have been cast with pent-roof combustion chambers. This modification of the LS1 has decreased the cylinder size thus promoting a greater Compression ratio; from 10.1:1 to 10.5:1. The LS6 ports have been cast using tighter tolerances which has resulted in increased power, thermal efficiency, and increased volumetric efficiency.

• High-Profile Camshaft

The LS6 utilizes a camshaft constructed from steel billet materials. The timing of the camshaft has been altered by increasing the lift from those of the LS1 to provide quicker opening times. To accommodate higher lift and longer duration of the camshaft the valve springs have been manufactured to become stiffer. The springs are wound tighter than those in the LS1 which results in stronger springs able to handle the increased strain from the camshaft. These modifications result in more efficient air-flow into the combustion chambers and thus an increase in power.

• Fuel Injectors

The LS6 utilizes new and larger fuel injectors. The new injectors deliver 3.6 grams of fuel per second an increase of 10% above the LS1. The injectors were designed to deliver more fuel as a result of the increase in air flow from the increased compression and camshaft opening duration modifications. The fuel to air mixture ratio needs to remain proportional to achieve operational status.

• Internal PCV System

The LS6 utilizes a newly designed Positive Crankcase Ventilation valve. The new PCV valve now rests in the "V" of the engine. The "V" aluminum cover contains composite oil separating baffles with unique tubing. This results in less overall oil tubing thus reducing the potentiality of oil leak sources. The presence of the oil baffles also reduces oil consumption and increases the performance capabilities of the ventilation system during high-performance maneuvers (greater than 0.55 lateral G) which the Z06 is capable of.

• Exhaust Manifolds

The LS6 utilizes newly designed exhaust manifolds. These manifolds are constructed of cast-iron material and have been designed to reduce weight by utilizing thin walls.

Z06 Walkaround

The C5 Z06 with a strong LeMans racing heritage

The Z06 received several other refinements in addition to its unique engine, suspension, wheels, and tires that either enhance functionality, differentiate its appearance from the base-model C5, or do both:

• Screened air inlets in the center of the front fascia that deliver additional cool air to the intake system.
• Air scoop inlets on the sides of the front fascia that funnel air to the front brakes for better cooling. These inlets replaced the fog lamp housings and/or associated trim panels of the base-model C5.
• Air scoops on the rear rocker panels that funnel air to the rear brakes for better cooling. Z06 rear brake temperatures are reduced by as much as 10% under competition conditions; brake fade and wear are also greatly reduced.
• Interior details: Z06 embroidered on each seat's headrest and a tachometer with Z06 imprinted on the gauge's face and a 6500 redline.
• Flat underside body panels that provide superior aerodynamics and help in achieving a 0.29 drag coefficient. ^[9]
• Z06 badges on the front fenders (see the Z06 Emblem below).
• Different front and rear brake pads than a normal C5 with distinctive red painted calipers (compared to black or bare calipers on the base-model C5)
• C5 Z06 Making a Sub 8 minute lap at The Ring!!

Those awesome Z06 brake calipers!

The Last C5 - a 2004 Commemorative Z06

For years, the search for the last Corvette of a generation has been an adventure for Corvette lovers. Discovering what the last VIN number is of the last-ever Vette built on that platform has been the easy part. The hard part-finding the car that matches that VIN-makes searching for a needle in a haystack look easy. (Especially if, when found, that last-ever car is not intact, with any unique parts scattered far and wide.)

When it came time to add a "last-of" Corvette to his stable, Mike Yager went in another direction-the easiest one by far. "This car was actually given away by the National Corvette Museum, and I ended up buying it from the winner," Mike says. That's right, he purchased a car that had been identified as the last-ever Z06 C5 built.

Mike already had the last C4 Corvette in the MY Garage collection at Mid America Motorworks, so when the opportunity for a similar last-call C5 came up, he took it. "They're cool cars to have," Mike says of his last-of-the-line Vettes. "The first one of a generation is cool, but so is the last. The fact is that every C5 made came before this car. After this one, there were no more C5s."

With all that performance hardware, it seems almost criminal to let a car like this spend all its time parked in a museum. When we chatted with Mike, this car already had some 4,600 miles on it. "The travesty out there is, if you look at some of these 'last' cars, they were taken out and driven as vehicles and have virtually disappeared," Mike says.  The same can be said for the Commemorative LeMans Z06.  This is one of the fastest and probably the most fun to drive Corvette ever made and many of them just sit in garages in collections.  Most people have only seen these cars on the Internet or at car shows.  This is a Corvette that begs to be driven!!