Ride and Handling Ok. We've talked about the stunning, 2005 Vette exterior, its refined interior and its 400-hp engine but, how does the new C6 ride, handle and stop? Can it take you on a long trip in comfort and style? Will its handling and braking please the sporting driver? The answer to both is "Yes!

Even in a base car, such this LeMans Blue Coupe (which happens to be 2005 Corvette VIN 0001) powering out of corners is a little easier with C6, in spite of 50 more horsepower. Image: Richard Prince.

After reduced road noise and more power, the third thing a C5 owner stepping up to the sixth-generation Vette will notice is a nicer ride. A significant reduction in harshness was achieved with the new Goodyear run-flat's more compliant casing. There is an additional improvement in ride quality over dips, swales, speed bumps, potholes and the like though an increase in suspension travel and revised shock absorbers to match the increased travel. These two improvements result in a base C6 Vette having a "near Buick" ride and the Z51 riding a nicely as did the C5 base models. Many people have a hard time believing that high-performance sports car can ride as nicely as the 2005 Corvette. Visit Tom Henry Chevrolet and we'll gladly demonstrate this very desirable characteristic of the C6.

Another ride and handling feature new C6ers may notice just driving around town is how the car tracks on roads with troughs or ruts. One of Team Corvette's goals was to reduce C5's slight tendency towards "trough-wander". This is can be a problem on some old or poorly-constructed asphalt roads which carry a lot of heavy truck traffic. The trucks eventually cause troughs where their tires run. If a car trough-wanders, its tires tend to "climb" the sides of the troughs. The driver feels this as a "pulling" right or left. Many blame this on brakes because they most often feel it when slowing down on a troughed road and braking amplifies the problem. A change in front suspension geometry for '05 reduced the Vette's tendency to trough-wander.

A feature of C5 basic architecture was ride decoupled from handling and that carries into the C6. It allows the car to ride better than competitors, such as the Dodge Viper and the Porsche 911, while maintaining a level of handling that equals or exceeds that of those competitors.

All the '05 Vettes handle better than their '97-'04 predecessors but, the real rocket ship on the street, the autocross course or a race track–at least until the 2006 Z06 arrives–is the six-speed Z51 Coupe. Hard performance numbers show it's incrementally off the pace set by the 405-horse, 2004 Z06; but in a straight line; it feels the same and, when driven to the limit through twisties, it feels better.

For more than 20 years, Z51, has been Corvette's mainstream, high-performance option. In the C6 era, Z51 evolves. In fact, handling-wise, it's about 3/4ths the way to an '04 Z06 and it gets that far in a quieter, nicer-riding, easier-to-drive and less-expensive manner. Order a C6 from Tom Henry Chevrolet and check the Z51 box and you'll get higher-rate springs, higher-rate antiroll bars and larger-diameter (36-mm vs 25-mm) more stiffly-valved shocks, bigger brakes, special tires, a power steering cooler and, on six-speeds, a trans. cooler.

Note the much flatter cornering attitude of a C6 with Z51. This is why, if you're going to drive fast in the turns on a regular basis, you need to order your Vette with that option. Z51 is available on both Coupes and Convertibles. Image: Tom Henry Racing.

A major contributor to this car's almost-Z06-handling, is the new, Z51-specific tire, the Goodyear F1 Supercar EMT. In a nutshell, it's the '01 Z06 tire with slightly more tread depth, slightly less tread width and the more compliant third generation, Goodyear EMT casing, a combination which is a great mix of the original Supercar's outstanding grip, improved wet performance and, of course, runflat ability.

The F1 Supercar EMT has, obviously, the EMT construction. It also has slightly deeper tread depth for better performance in the wet and a modest increase in tread life. Image: Richard Prince.

GM has a new facility at the Proving Ground called the Milford Road Course or "MRC". It was patterned after Nurburgring, the famous German test track. MRC is 2.9 miles long, has 20 turns and a 135-ft. in elevation change. At the end of its longest straight, Corvettes are at the top of fourth gear, a little short of 150 mph. This track's most demanding aspect is that every turn has both lateral and vertical accelerations, so when you turn; you get heaved up or slammed down. Is MRC a performance driving challenge? You bet!

Tom Henry Racing's test driver had five laps in an '05 Z51 about as fast as he could go on sections of MRC he learned in the short time we were there. He reports that the car is impressive. Compared to last year's Z06, corner entry is more refined. Going in, a C5 was good but, sometimes, just bit on the oversteer side so, it was never easy to trail brake. Also, if the road was rough, because the front end was on the bump stops occasionally, the car was a little nervous.

Driven hard into turns C6es, both base and Z51, are more neutral. Note the C6's suspension geometry on the left front corner. The tire is flat on the road giving maximum contact patch and the best handling. Image: Richard Prince.

The '05, especially under braking, is more tail-in. Plus, on a rough or undulating surface, it's less likely to touch the jounce bumpers and that keeps the front end planted more securely. Better manners going into a turn helps the driver be smooth and–smooth is fast. This more settled behavior comes from increased ride travel with shock valving to match, the improved Goodyear run-flats and increased limited-slip differential pre-load.

In the midpoint of a turn, because of increased grip from the F1 Supercars and more roll stiffness from bigger antiroll bars; the car's lateral acceleration increases. Z51s generate about 0.99g lateral acceleration, a number which is right there with the '04 Z06. As you're more stable transitioning from corner entry, you're not having to calm a slightly iffy car near the apex. In turns with dips or bumps, extra travel and changes in shock valving have the car more poised, so, even when driving at the limit; it rides better.

Here's Z51 powering off a turn. Again, the outside front tire is planted flat on the road. Image: Richard Prince.

Off turns, C6 gets the LS2's additional torque down very well. Once again it's, increased travel, revised shock valving and more compliant tires making the difference. Also, helping is stability elsewhere in the turn, ie: if you come in a little less tail-out and do the apex with more finesse; that smoothness carries into the exit, giving you a faster speed out. In summary, the THR test driver's assessment is that the new Vette's at-limit-handing is more easy to manage. The car responds crisply in transitions.

Extra ride travel keeps the suspension off the jounce bumpers and makes driving a Z51 at the ragged edge a less ragged experience. The brake enhancements may not be noticed much on the street, but drive the car hard and it stops better and more consistently as heat builds in the brakes.

Quicker. Faster. Better handling. Nicer Riding. Better brakes. Almost last year's Z06 for less money. What's not to like about the new Z51?

We also had a chance to evaluate a base coupe on the MRC and we can say that, not only does the new Z51 handle almost as well as the '04 Z06, but base C6es are better in many aggressive driving situations than were the last generation's Z51s. No matter which '05 Corvette you drive fast, you look better and are more comfortable while being just that little bit quicker in the corners.

The Sixth-Generation Corvette chassis retains the basic architecture of the groundbreaking 1997 model: front engine, rear transaxle, low-mass and high stiffness in bending and torsion.

Backbone structure, hydroformed steel frame rails, closed steel driveline tunnel, steel bulkhead behind the seats, balsa-wood-cored composite floors and aluminum cockpit structure, all pioneered in C5, continue in enhanced form for C6. To reduce the length of the car, 2.4-inches were taken off the front of the hydroformed rails and the fore/aft width of the front bumper beam was thinned by 0.63-in. In the rear, shortening was accomplished by more efficient placement of the energy absorbing foam used to enhance the car's crashworthiness, shortening the rear bumper structure and the redesign of the rear fascia.

Image: GM Communications.

In addition to dimensional changes, in the interest of increased stiffness and weight reduction, the C6 structure was also upgraded by 1) a materials change in the tunnel "close-out panel" from steel to aluminum, 2) a reinforced instrument panel, cross-car beam and 3) the addition of composite reinforcements to the rear compartment tub and aluminum braces under the tub.

What were the ride-and-handling goals for C6? For that we spoke to Mike Neal, Corvette's ride-and-handling Development Engineer with whom we spoke briefly during our "infiltration" of the Milford Proving Ground on June 4th.

"Everything on the C6 starts with the C5," Mike Neal told the THR. "We asked, 'Ok. What do we like? What could we improve on? What takes an architecture change to improve something we couldn't on C5?' We wanted to improve ride. We wanted to decrease noise. We wanted to improve handling."

To do all that required redesigning the suspension. At first the parts seem the same as those on a C5 but look close; and you see almost nothing carries-over. In the front, the suspension cross member, steering rack, control arms, antiroll bar, shocks and knuckles are new. This was to increase the front ride travel, add one degree caster to reduce "trough-wander" and to stiffen the knuckle for less deflection under heavy braking.

In the front of a C6, the tires, wheels, knuckles, control arms, antiroll bar and steering gear are new parts. Image: GM Communications.

In the rear, the cross member, control arms, antiroll bar, spring, shocks and knuckles were redesigned. This was to increase ride travel, allow relocation of the spring above the control arms, allow a second transaxle mount to improve damping of powertrain movement and to stiffen the knuckles for less deflection under braking. Brake pieces are new, too. C6 base brake rotors have more mass, a revised hat section, thicker brake plates (the part of the rotor swept by the pads) and different venting. All this was done to reduce thickness variation due to heat cycling and to eliminate brake noise. Brake calipers are still aluminum, but otherwise are a new design which is stiffer across the bridge, has less parts and less brake drag.

The master brake cylinder has been redesigned to make it more durable. The antilock brake/traction control/stability enhancement system controller and modulator valve assembly are new designs which respond more quickly and are designed for GM's LAN system rather than the old Class Two communications. The uplevel brakes are heavier-duty because of Z51's higher-performance nature. They include larger, cross-drilled rotors, different calipers (to fit the larger rotors) and more aggressive pads. The rear brakes have smaller pistons to make brake bias more optimal during heavy braking in aggressive driving situations.

The C6 brake system was significantly revised with new knuckles, a stiffer brake rotor and a more robust brake caliper. Image: Richard Prince

One big contribution to C6's improved ride and handling i the new, third generation, Goodyear EMTs. So far, there are two: the Eagle F1 GS-2 EMT, for base and F55 cars, and the Eagle F1 Supercar EMT on Z51s. The story of the third generation, Goodyear "Extended Mobility Tire" is an article in itself. Goodyear Engineers Larry Jansen and Nick Hill, worked with Mike Neal, in developing a new approach to run-flats.

The first two generations of Goodyear run-flats, the GS-C EMT of 1994 and the F1 GS EMT of 1997, had very stiff casings because, once deflated; stiffness was necessary for safe handling.

With a revised, low tire-pressure warning system, which communicates with both the driver and the car's standard stability enhancement system, "Active Handling", C6 relies partially on Active Handling, which goes into a more aggressive, safety-oriented mode when low or no tire pressure is detected, for safe handling on flat tires. Because the tires are no longer required to provide 100% of the handling necessary for safe, runflat operation, the third generation EMT casings could be softened in some areas and significantly softened in one specific area.

The result is a runflat which rides better, is quieter and improves handling when the car is driven near the limit on tires inflated to the proper pressures. The new Goodyear EMT's on the front of C6es (P245/40ZR18) are the same width as those on C5 but are on an inch-larger wheel. The tires on the rear (P285/35ZR19) are a bit wider and, also, mount on inch-larger wheels.