CHEVROLET Z06

RACING PEDIGREE

Please don’t mistake me for one of those P-car loving Corvette haters. I may have just described one of the fastest and most powerful Corvettes ever built as a blunt force instrument featuring antiquated technologies like pushrods and transverse leaf springs, but sometimes a good old-fashion sledgehammer really is the right tool for the job. Corvette Racing has certainly hammered the competition over the last decade, winning their class six out of the last ten times at the 24 Hours of Le Mans to go along with eight straight GT1 ALMS championships from 2001 to 2008. I’m sure a lot of us assumed Corvette Racing would lose some of its magic with the new GT2 car and the economic crisis facing GM, but the new C6.R didn’t miss a beat in 2009, posting five podium finishes and notching its first GT2 win at Mosport International Raceway on August 30th.



PUSHROD PERFECTION
Given that the C6 Z06 was co-developed by the Corvette Racing team, it should come as no surprise that its on-track performance level is astoundingly high. A big part of its amazing pace around Spring Mountain Motorsports Ranch’s 3.1-mile 18-turn main circuit is the highly refined pushrod powerplant under the hood. With 7.0-liters of displacement (427 cu.-in.), the Z06’s LS7 V8 is the largest small block Chevy has ever put into production, and its 505-hp and 470 ft-lbs of torque are second only to the mighty ZR1 and its supercharged 638-hp (from 6.2-liters of displacement).


What these numbers don’t tell you is how broad and useable the powerband really is, the LS7’s over-square design (104.8mm bore and 101.6mm stroke) allowing it to eagerly rev to its 7000 rpm redline while producing over 400 ft-lbs of torque from 2400 to 6400 rpm.


Nor do the numbers tell you that the dry sump oiling system is designed to prevent oil starvation while achieving over 1 g of lateral acceleration around the high-speed sweepers at Spring Mountain. The forged pistons and crankshaft, titanium intake valves and connecting rods, and sodium-filled exhaust valves further bulletproof the LS7 while simultaneously reducing mass such that it can safely spin to much higher engine speeds than is typical for a pushrod V8.


The Corvette Racing team likely played a part in selecting the Z06’s transmission gear ratios as well, because the solid-feeling six-speed Tremec T56 is perfectly matched to the LS7’s powerband. Acceleration is frantic in every gear, the tall first gear allowing 0-60 mph runs to be achieved in as little as 3.6-seconds. Just as impressively, with some skill, the quarter mile flies by in 11.7-seconds at around 125-mph. These straight line figures feel entirely realistic as I blast down Spring Mountain’s 1,830-ft back straight, grabbing 5th gear at 150 mph (according to the digital heads-up display that seems to hover in space above the dash) before braking and downshifting into 4th for the high-speed 400-ft radius right-hand Turn 8.




LIGHTWEIGHT CHASSIS
It’s during braking and while balancing the chassis on the edge of adhesion in high-speed corners like Turn 8 that the Z06’s most impressive statistic reveals itself. Tipping the scale at just 3,147 lb, the long nose and weighty appearance of the Z06’s flared fenders and massive wheels, tires and brakes seem downright dishonest once you turn off all the stability and traction control aids and allow the chassis to work its magic. The source of its mojo being the use of lightweight materials throughout – from aluminum frame rails to a magnesium-alloy roof and carbon fiber and balsa-sandwiched floorboards, the Z06 has shed 150 lb compared to the standard C6 (which is hardly a porker at 3,296 lb).


One particularly famous reviewer on the other side of the Atlantic seems to find the Z06 virtually uncontrollable when driven in anger around a race track, but thanks to the expert guidance of the instructors at Spring Mountain’s Ron Fellows Performance Driving School (which has a huge fleet of C6 Corvettes including many Z06s and even a few ZR1s) I’m sliding this sledgehammer of a car around with scalpel precision. With so much power on tap it’s never difficult to induce some tail wagging fun, but the Z06’s low mass and stiff chassis give it surprisingly quick reflexes, making it easy to counter the slide with a little flick of the steering wheel and a touch of restraint with the right foot.


NEEDS MORE GRIP
With ambient air temperature in the neighborhood of 120-degrees, it’s not the outstanding Brembo brakes that fade but the tires. This comes as something of a surprise given the hulking dimensions of the Goodyear Eagle F1 Supercar tires the Z06 comes standard with, measuring 275/35/18 up front and 325/30/19 out back. That’s a lot of rubber on the road, which goes a long way to explaining the 0.98 g of cornering power the Z06 is able to achieve in a 300-ft diameter skidpad test, but in the scorching heat at Spring Mountain the tires quickly overheat. This results in even more power sliding and counter-steering than intended, a controlled dance that may be a lot of fun but is certainly not the fast way around the circuit.


To get the most out of a car this powerful and this capable on the brakes and in the turns, a set of DOT track tires like Michelin’s Pilot Sport Cup would be an excellent investment. Don’t get me wrong, I’m sure the OE Goodyears are an excellent street tire and a capable track tire for a lap or two, but if you want to go lapping and enjoy a car like the Z06 to the fullest, stickier rubber designed for the higher heat generated by track-day abuse would be a good investment.


THE COMPETITION
Pricing for the 2010 Corvette Z06 starts at $75,235, which is an increase of $360 over 2009's MSRP of $74,875. The higher sticker price is a function of a few new additions to the Z06’s spec sheet including Launch Control and side airbags. In this price range the Z06 has no real two-seater sports car competition, but in the bang-for-the-buck category the 2010 Nissan GT-R is probably it’s most worthy adversary.


At $81,790 the GT-R is in the same ballpark as the Vette, and although it’s a much heavier vehicle (3,814 lb) and makes less peak horsepower and torque (485-hp and 434 ft-lbs), its all-wheel-drive design and highly advanced traction control system allow it to accelerate from 0 to 60 mph in just 3.5 seconds and complete the ¼-mile dash in 11.9 seconds at 120 mph. That’s right on-par with the Z06, as is the GTR’s skid pad lateral g reading of 0.98. In the city the GTR has a slight fuel economy advantage (16 mpg to the Z06’s 15 mpg), but the tall 6th gear of the Vette gives it a marked fuel economy advantage on the highway (24 mpg to the GTR’s 21 mpg).


Perhaps the Porsche 911 Carrera Coupe should also enter the discussion, since it’s competitively priced at $77,800. But it’s simply no match for the Z06 (or GTR) from a power (350-hp and 295 ft-lbs) or performance perspective (0-60 mph in 4.6 seconds, ¼-mile in 13.1 seconds). The 911 does offer greater badge prestige (or snob appeal, depending on your perspective) along with high build quality and slightly better fuel economy (17 city, 26 highway). The Dodge Viper may also be worth some consideration given its hugely powerful V10 engine (600-hp and 560 ft-lbs) and impressive performance statistics (0-60 mph in 3.7 seconds and the ¼-mile sprint in 11.8 seconds), but a sticker price more than $10,000 higher than the Z06 and the fact that it’s going out of production in July serve to make it a less relevant comparison point.


THE VERDICT

In a class of its own, as far as two-seater sports cars under $80,000 go, the 2010 Chevrolet Corvette Z06 is not without its faults. It has been widely criticized for its interior quality, lack of seat bolstering (perhaps my biggest pet peeve), and that infamous “flapping in the wind” cloth rear trunk cover, but these complaints really should be measured against the Z06’s MSRP. It can also be a handful to drive if you turn off all the nanny controls and are a bit ham-fisted behind the wheel, but building a high-performance variant that includes carbon fiber front fenders, a dry sump oiling system, a magnesium-alloy roof and a highly developed V8 engine for this kind of money really is an astounding achievement. And despite the often-ridiculed transverse leaf springs, this sledgehammer of a sports car has an impressively refined ride quality to go along with its racecar-like performance potential.


Sure I’d like more supportive seats, a heavier and more positive feel to the steering, and higher quality interior plastics, but the exterior styling is wonderfully aggressive and the driving experience can be as wild or as restrained as you want it to be. It may not be the most technically advanced piece of engineering in the sports car world, but you simply cannot buy more speed per dollar than this amazingly effective sledgehammer of a car offers.