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Illustrated Corvette Series No. 187 - 1997 Corvette
"The First C5 Corvette"
So much has happened in the 16 years since the C5 arrived it’s easy to forget how advanced the C5 was. The C5 was the most radically changed production Corvette of all time. By the late ‘80s, aside from the ZR1, engineers and designers had done nearly everything they could to the C4. Chief engineer Dave McLellan pitched the C5 as an early 90s car, but since the Corvette was selling well, the C5 kept being pushed back. At some point, it was obvious that the C5 would not arrive by the time McLellan retired in November ‘92. His successor shook the Corvette troops. Dave Hill had honed his craft as a Cadillac engineer, eventually becoming Engineering Program Manager early in ‘92. Hill’s Cadillac quality expertise is exactly what took the new Corvette to the next level.
When the C5 debuted in the summer of ‘96, it wasn’t quite what the press was expecting - it was more! Not only was the C5 bigger, more slippery, and rounder, under the skin was an all-new hybrid parimeter-backbone frame structure, 4-wheel double-wishbone independent suspension, aluminum transaxle, a roomier interior, and best of all, a totally new, all-aluminum small-block Chevy engine. When the press finally drove the ‘97 Corvette, they loved it!
The externals were as follows. Wheelbase grew 8.3-inches to 104.5, length increased 1.2-inches to 179.7, width grew 2.9-inches to 73.6, height was increased 1.5-inches to 47.8, and the track increased 4.4-inches in the front and 2.9-inches in the back, 62.0-inches and 62.1-inches respectively. The only aspect of the C5 that got heat was the car’s high, big butt, however the upside was nearly double the cargo space from the C4, which no one complained about.
The C5 was designed from the beginning to be a roadster. The completed structure was four times as stiff as the C4 with lower side sills making ingress and egress much easier. The interior was just a little bit bigger in every direction, providing the driver and passenger more room to move about. The dash was based on the classic C2 dual-cove design with a passenger-side grab-bar. Leather seats were from Lear and the speedometer went up to 200-mph.
The biggest breakthrough was the LS1 engine. Only the 4.4-inch bore spacing was shared with all previous SBC engines. Arguable the LS1 was the oddest-looking SBC ever. The intake manifold looked like it had 8-pack abs and the aluminum valve covers had an ignition coil for each cylinder. The dream of an all-aluminum engine for the Corvette dates back to the 1957 Q-Corvette proposal Aluminum heads went in production from ‘67 to ‘69 on the L88, but didn’t come back until ‘86 on the L98. And the ZL1 427 showed up briefly in ’69.. The LS1’s block, heads, intake manifold, and oil pan were integrated into one massively strong structure with deep skirts, ribs, and cross-drilled 4-bolt mains. Measuring 346-CID, the 10.1:1 compression LS1 was rated at 345-horsepower @ 5600-rpm and 350 lb/ft of torque at 4400-rpm. The sequential fuel-injection system was compact for a low hoodline, the redline was 6000-rpm, and the completed engine weighed 44-pounds less than the ‘96 LT4.
Surprisingly, the C5 had smaller tires. The five spoke aluminum wheels measured 17x8.5 on the front and 18x9.5 on the rear, and were shod with Goodyear Eagle F1 GS tires, P235/45ZR17 on the front and and P275/40ZR18 on the rear. Even though the C5 was bigger than the C4, it weighed in at 3,218-pounds, 70 less than the C4. With 45 extra horsepower on tap, the C5 was now the quickest and fastest base model Corvette, capable of 0-to-60 in 4.72-seconds, the 1/4-mile in 13.36 @109-mph, and a top speed of 175-mph with the manual transmission. Mileage figures were 18 city and 28 highway. For more spirited driving there was the F45 Selective Real Time Dampening option for $1,695 that provided Tour, Sport, or Performance shock absorber settings. And for serious performance driving there was the $350 quasi-racer Z51 that used stiffer springs, stabilizer bars, and shocks. The C5 was completely and totally new, and did everything better. All that for a base price of $37,495, up just $270 from ‘96.
Dave Hill and his team made the C5 nearly perfect right out of the box. Hill said that they strengthened the C4’s weak points, the good things were made great, and the great things made better. The car was so good that by ‘99 it was obvious to Hill’s team that to take the car to the next level, they shoud start the C6 right away.
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Illustrated Corvette Series No. 169 - Callaway C12 Corvette
"Built To A Standard, Rather Than A Cost"
“Specialty cars” have been with us for almost 100 years. As long as there have been those with deep pockets, there have been craftsmen who said, “I can build you a special machine - for a price.” By the end of the ‘60s, a few small shops and car dealerships began offering personalized performance cars. Names such as Shelby, Dana, Nickey, and Baldwin-Motion became legends. Although the performance party was over after ‘70, the passion never went away.
In the mid-’70s, Reeves Callaway was a young foreign car enthusiast fascinated with turbocharging. Turbos had been used on the ‘60 Corvair and Olds Jetfire V8, but it was the 1,000-HP ‘73 917/30 Porsche racer that captured the imaginations of speed freaks everywhere. Callaway began developing quality turbocharger kits for BMW, VW, Porsche, Audi, Alfa Romero, and Mercedes-Benz cars. The introduction of the the C4 Corvette was a very big deal in ‘84, but what was missing brute horsepower. Corvette chief Dave McLellan and his team soon began work on what would become the LT5-powered ZR-1 supercar, but it was going to take some time. Enter turbo-master, Reeves Callaway.
Based on the reputation of Callaway’s quality work, the Callaway Twin Turbo (option B2K) was officially added to the ‘87 Corvette order form, for a whopping, $19,995 on top of the $27,999 Corvette base price! The new Callaway Corvette packed 105-HP more than the stock 240-HP L98 engine. The torque rating on the twin-turbo beast was 465 FT/LB. Unlike the future Callaway Corvettes, the only clue of anything unusual about the car were the Dymag wheels.
In ‘88 a specially prepared 898-HP twin-turbo street Corvette, dubbed, “The Sledgehammer” smashed speed records with a 254.76-MPH blast at the Transportation Research Center in Ohio. The car was wearing a unique body kit designed by Paul Deutschman that became the new look of Callaway Corvettes. But with the arrival of the ‘90 ZR-1, ‘91 was the last year for the official B2K Callaway Twin-Turbo option. So while the Corvette team was developing the C5, Callaway was building ZR-1-based customer cars, as well as developing his own radical C7 GT1 racer.
With the arrival of the C5, Callaway finally had a structure to build a world-class supercar. The C12 road car was built to homologate the machine to qualify as a “production car” so that the racing version could compete. The C12 was built to a standard rather than a cost in a two-stage process. A new C5 Corvette was first sent to IVM (now Semcon) in Germany for structural enhancements. The entire car was disassembled and fitted with hand-fabricated upper and lower A-arms with adjustable coil-over-shocks to supplement the stock transverse plastic springs. Suspension mods made the car 5.1-inches wider by putting the wheels farther outboard. Over-sized 12-inch diameter Alcon brake rotors are added and Pirelli P-Zero 295/30ZR19 tires will be used on lightweight wheels.
The interior is trimmed in customer specified colored leather with custom gauge faces and carbon fiber surrounds. Leather covered Koenig custom bucket seats are installed along with whatever sound system the customer wanted. Aside for the glass, windows and roof structure, the Paul Deutchman-designed fiberglass, carbon fiber, Kevlar body completely replaced the stock exterior and was available as a coupe, hardtop with a removable roof panel, or convertible/roadster. The completed body was then painted to customer specs.
After being sent to Callaway’s Lyme Connecticut shop for engine installation and finishing, the LS1 engine is balanced and blueprinted. The combustion chambers and pistons were completely reworked, cam profiles were modified, and the factory computer chips were reformatted. The finished Callaway treatment yielded 440-HP, a 95-HP increase and 420-FT/LB of torque, a 70-FT/LB increase over the stock L98.
For all of the extra components and size, the car only weighed 135-pounds more than the stock version. For its day, performance figures were astonishing.; 0-60 in 4.2-seconds, 1/4-mile in 12.8-seconds, and a top speed of 188-MPH. The completed C12 was so far removed from the production Corvette that European destined cars were registered a “Callaway.” And lastly, the price. Between the variations and options, a Callaway C12 cost between $170,000 and $220,000.
Some perspective. While those performance numbers look somewhat tame by ‘11 standards, not so twelve years ago. Yes, the price is very high, but from ‘97 to ‘01, only 20 cars were built. Each car is unique and a member of a very limited club of truly custom Corvettes. Judging from the current value of the surviving Baldwin-Motion Phase III GT Corvettes, the Callaway C12 cars will be million dollar machines in 30 years. Easy.
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Illustrated Corvette Series No. 104 - 1997 Corvette
"The C5 Arrives!"
The C4 Corvette was not supposed to have a 13-year run. Chevrolet product planners were hoping to get the C5 released in 1993. GM was having serious financial problems in the early '90s, and a new Corvette was the last things they were concerned about. When the C5 project was finally approved, it was given a $250-million dollar development budget - a dismal amount of money to develop a completely new car. Some models receive that much just for a simple restyling. Dave Hill and his team got to work and the results were better than anyone expected.
This would be the first time a Corvette would be completely redesigned using virtually no carry over parts. As advanced the C4 was over the C3, by the '90s it was a 10-year old design in a market full of newer designed sports cars. Hill and his designers were very much aware of the Corvette's short comings and set out to fix everything that wasn't right with the C4. The only carry over part was the 4L60-E automatic transmission and a few fasteners.
The basic layout and materials selection was actually proposed in the 1957 "Q-Corvette" concept study. Duntov had proposed a new Corvette featuring a fuel-injected, all-aluminum engine, a transaxle, 4-wheel independent suspension, and more. Although it took four generations and 40-years, the essence of the Q-Corvette was alive and well in the new C5 Corvette.
The new C5 was bigger in every dimension, yet it weighed 80-pounds less than the '96 Corvette. The length went from 178.5-inches to 179.7-inches, the width went from 70.7-inches to 73.6-inches, the height went from 46.3-inches to 47.8-inches, the front track was increased 4.4-inches in the front and 2.9-inches in the rear. Even thought the car was larger in every direction, the new styling was lean and slick.
The new LS1 engine was like the ghost of the famous ZL-1, 28 years before. The LS1 was an all-aluminum engine with cross-bolted 4-bolt main bearing caps, cast-in cylinder liners, a shallow aluminum oil pan with side reservoirs, a composite intake manifold, aluminum valve covers. Also included was a hollow camshaft, separate ignition coils for each spark plug with crankshaft and camshaft sensors, and double-lined exhaust manifolds. The complete engine weighed 44-pounds less than the '96 LT4. Horsepower was 345, up from the LT4 rating of 330.
Using a transaxle in the back end of the car helped create a near 50/50 front-to-rear weight ratio. Buyers had a no-extra cost choice of either an electronically-controlled 4-speed automatic or the new Borg-Warner 6-speed manual with a limited-slip Getrag rear axle.
The all-new interior featured Lear leather seats, complete analog gauges,
a centrally-located barking brake handle, and a glove box located under the passenger-side air bag.
The suspension used front and rear double wish bones, transverse composite mono leaf springs, and thicker brake rotors with no-pulse anti-lock calipers. The new perimeter frame was made of stainless hydro-formed tube steel, with aluminum, and magnesium bracing.
Even cynical car magazine writers were impressed with the fact that the new C5 did everything better that the '96 Corvette. A long-standing complaint about Corvettes has been body rattles and noise. Engineers were able to get the body vibrational frequency up from 15 hertz to 23 hertz. The Mercedes SL Convertible had a frequency of 19 hertz. But the real kicker was the price increase - up only $270 from the '96 model! Yet performance was better that the exotic ZR-1. With 0-60mph times of just 4.7-seconds, quarter-mile times of 13.3-seconds at 109mph, and a top-speed of 172, what was there not to be happy about?
The Corvette team created a winner with the new C5 Corvette, but it took the public a year to catch on the new design. Sales for the '97 Corvette were less than half of the '96 figures, only selling 9,752 units. However, the following year sales more than tripled to 31,084 units. The '97 C5 was just the beginning of an amazing generation of Corvettes that finally yielded the ultimate world-class sports car victory at the 2004 24-Hours at Le Mans in the GTS class. Zora Arkus-Duntov would have been very happy. - K. Scott Teeters