Repair-It

Some 2014-2016 Corvette owners may want the vehicle’s wheel alignment set-up for track events and competitive driving. (Fig. 11)
The vehicle must be returned back to the original specifications after the driving events.
Changing the alignment for driving events is not covered under the GM warranty.

The 650-hp, 2016 Chevrolet Corvette Z06 is one of the most capable vehicles on the market, capable of accelerating from 0 to 60 mph in only 2.95 seconds, achieving 1.2 g in cornering acceleration, and braking from 60-0 mph in just 99.6 feet.

TIP:
Using these wheel alignment settings may cause excessive tire wear.
Remind customers to only use these wheel alignment settings for track events or competitive driving.

The following track event and competitive driving wheel alignment settings apply to vehicles equipped with the Z51 package, Z06 models and Grand Sport models.
When performing the wheel alignment, do not adjust the trim height.

The alignment should be performed by first removing washers between the upper control arms and frame. (Fig. 12)

Z51 – Remove a maximum of one washer per front upper control arm bolt and one washer per rear upper control arm bolt.

Z06 – Remove a maximum of one washer per front upper control arm bolt. Do not remove washers from the rear upper control arm bolts.

Grand Sport – Do not remove washers from the front or rear upper control arm bolts.

control arm washers Fig. 12

Adjust the lower control arm cam bolts until alignment is within the alignment specifications listed in the appropriate Service Information.
The Owner Manual Track Events and Competitive Driving section does not list a +/– tolerance for any of the alignment specs.

Front (per corner)

Caster: +7.0 degrees

Camber: –2.0 degrees

Toe: 0.05 degrees toe in

Rear (per corner)

Caster: 0 degrees

Camber: –2.0 degrees

Toe: 0.05 degrees toe in

Thrust Angle: 0 degrees

Digital Angle Gauge Required for Corvette Rear Wheel Alignment

As part of a rear wheel alignment on the 2014-2016 Corvette for track events and competitive driving, the rear wheel caster must be set. to measure rear wheel caster, a digital angle gauge and an adapter, which attaches the gauge to the rear knuckles, are required.

The gauge must be capable of accurately measuring to 0.1 degree. It must also have a calibration feature and a magnetic base so it will attach to the adapter.

Adjusting rear caster was not part of the alignment process on the 6th generation Corvette.

For the C7 Corvette introduced in 2014, the rear caster adjustment allows for the ideal suspension geometry regardless of factory build variation. Rear caster accuracy and symmetry is an important aspect of the ride steer performance.

Even small changes in rear steering angle can have a big effect of vehicle handling.

The C8 stopped from 70 mph in 149 feet and hung on to the skidpad at 1.03 g with quite a bit more understeer than we were expecting, considering our experiences on the road. Neither of those chassis metrics are improvements over the C7, which stopped in 139 feet and circled the skidpad at 1.06 g. Partial blame can be cast at the C8's weight gain. However, the full extent of the latest Corvette's handling superiority would play out during hot lapping at the racetrack.

The faster you go, the better the C8 feels. The steering cuts like a race car's, and the cornering limits are virtually out of reach on the street—though steering feel and feedback aren't as communicative as those from a Porsche 911 or a McLaren 720S. Boiling out of corners on full throttle, the big V-8 thunders like a NASCAR engine, and the dual-clutch automatic delivers crisp shifts when you pull the paddles on the back of the steering wheel.

Most of the time, you won't be blazing twisty roads like a four-wheeled flamethrower; you'll be wanting a car that's a little more Zen. Bimodal, everyday usability has long been a Corvette trait, and the C8 continues that tradition. In Tour mode, it transmogrifies into a laid-back daily driver, with a ride smoother than many sports sedan's, steering lighter than a Malibu's, and an engine note that's barely a murmur. The transmission eases through its eight gears unnoticed, though it can be a bit lazy to downshift if you stab the throttle. Extensive acoustic insulation has made the C8 not only quieter by three decibels at 70 mph than the C7, but just plain quiet. This kind of dynamic bandwidth is almost unheard of in the mid-engine exotic realm.

But normal driving also is where the C8 gets tripped up by elevated expectations. More than a few of us were hoping for more character, more drama, and more personality when we weren't hammering it. Ferraris and Lamborghinis snarl at you like caged tigers even when you're just moseying through downtown. The steering of Porsches and McLarens is more vivid than the Corvette's at low speeds. We sometimes wished the new Stingray felt a little louder and brasher, a bit more like the C7. Can a car that looks this angry actually be too refined? That's where the asterisk comes in.

The C8 also is the most impressive Corvette ever. Deleting all the fancy gear on our test car—it had all manner of extras that didn't make it drive better, including a $1495 front-end lift mechanism to clear steep driveways and $995 worth of carbon-fiber engine-compartment garnish—wouldn't change how we feel about it. But it would drop the price considerably. For a base car with the Z51 package and FE4 dampers, you're looking at only $66,890. This is nothing less than the democratization of the exotic car.

And consider this: The C8 Stingray is but the opening salvo in Chevy's supercar revolution. It's a known secret that several hotter C8s will soon follow, powered by high-revving, DOHC 32-valve flat-plane-crank V-8s starting at 600-plus horsepower and ranging up to a hybrid with nearly 1000 ponies. Those versions likely will deliver all the snarl anyone could want.

That's the future. This is now, and it's clear that the new C8 isn't just a better Corvette, but a supercar for the rest of us—imperfections be damned. You'll just have to readjust your expectations to suit.

The 911's turbocharged flat-six is down 80 lb-ft of torque against the 'Vette, too, but you wouldn't know it from the stopwatch. Be it 495 American ponies and 470 lb-ft from eight free-breathing cylinders fed to a Tremec eight-speed dual-clutch auto or 443 German thoroughbreds and 390 lb-ft from six pressurized pistons behind a Porsche eight-speed dual-clutch, you're getting to 60 mph from a dead stop in less than 3.0 seconds.

With the Porsche, it takes only 2.9 seconds, but the Corvette needs just 2.8, making it the quickest factory Corvette to 60 mph in history. The advantage carries through the quarter, the Corvette trapping in 11.1 seconds at 123.2 mph and the 911 in 11.2 seconds at 124.3. And these are just the base versions of each car. What a time to be alive.

Oddly, the Porsche looks and feels quicker. Something about the midrange oomph provided by the turbochargers gives the 911 a feeling of supercar urgency, from a stop or a roll, that the ultra-smooth Corvette lacks. The 'Vette's big V-8's power delivery is so smooth and so consistent everywhere in the rev range that it never feels like you've just hit hyperdrive. The cabin is so isolated that you never feel like you're going as fast as you are. It just goes.

It isn't just the rear end of the Corvette that is sensitive to grip. Even with slightly stickier Michelin Pilot Sport 4S rubber to the 911's non-Corsa Pirelli P Zeros, the Corvette manages 1.04 average lateral g on our skidpad to the 911's 1.09.

The Corvette's default limit-handling behavior is big, fat midcorner understeer, and it shows in the figure-eight laps. The Carrera laid down a truly blistering 22.7-second lap at 0.94 average lateral g to the Corvette's significantly slower 23.3-second lap at only 0.90 g. That's just barely quicker than the previous generation's Z51, which figure-eight master Kim Reynolds always found to be an unpredictable mess in this test despite the numbers it put up. He finds this new car communicative, responsive, and easy to drive (despite said understeer).

So how did that big midcorner push get past the Corvette engineers? We don't think it did. We think it's intentional. The vast majority of Corvettes sold are base models, and the vast majority of customers will never have driven a mid-engine car before, much less one this quick. Understeer is safe, in that it makes it very difficult for the car to oversteer—and when this car does oversteer, it's a very fine line between a sweet little drift and going backward off the road. Drivers who prefer exploring varying degrees of the safety net can choose from ESC Competitive mode when the car is in Sport mode (it's plenty lenient) or one of five Performance Traction Management modes with decreasing levels of computer assistance and intervention.

The Corvette's brake-by-wire pedal was a particular point of contention among the editors who had a go in both cars. Some had no issue with it. Others noted it would get into ABS before the pedal reached the end of its travel but disagreed about the difficultly in modulating braking once ABS was reached. Walton and I, crazy late brakers that we are, felt we didn't get enough feedback from the pedal and had to learn to anticipate when ABS would kick in while also trying to slow for corners and get the best lap time.

The resistance in the pedal didn't feel proportional to the actual braking force happening, making it feel as if the brakes were fading when they weren't. Bumpy braking zones only made matters worse in the Corvette, as the front wheels fought with the pavement and the ABS. At minimum, it was distracting, and at worst it hurt some of our confidence in the car—despite knowing it needs only 1 foot longer to stop from 60 mph than the Porsche.

Similarly, the 911's steering offered more feedback midcorner; you knew exactly how much front-end grip you had. Not to diminish the Corvette's steering, which was as accurate and precise as the 911's. Indeed, the Corvette's more damped steering was a virtue on faster sections of our makeshift track.
At triple-digit speeds, the Corvette feels solid and planted, but all the extra kickback in the 911's steering makes it feel nervous and light up front the faster you go. Nervous or not, the 911 saw up to 8 mph higher maximum speed on our "track." You can put it down to greater cornering speeds and the ability to roll hard into the throttle just after the apex—having the rear end rotate you slightly in the exit direction as it digs in and whips you off the corner harder than the Corvette could.

Add together those 911 advantages, though, and you get a car that never asks you to think about anything but your own driving. Giving you exactly the feedback you need from your inputs and predictable behavior at every turn, the 911 lets you focus on being a better driver, not driving the car better. It may be a semantic difference, but bear with me.

The Corvette is very nearly this good (and better than any Corvette that's come before it), but having to navigate the limits of the Chevy's ABS and understeer right at the critical moments makes you focus on the car as well as your driving—and thus costs you the precious tenths you lose to the 911. With a time delta this small, the 911 spends less than 1 percent of the lap ahead of the Corvette, and that's where you'll find it. The Corvette makes you feel like you're in a supercar, the 911 makes you feel like you're part of a supercar.

Where you won't find time is in the Corvette's hot new transmission. Many sports car makers have tried to match Porsche's class-defining PDK dual-clutch gearbox. Precious few have come close. But the Corvette does—on the first try, no less.

You won't find time in the dampers, either. The Corvette's fourth-generation magnetic dampers are the stuff of magic, keeping the car just as planted and confident in the corners as the 911 while providing huge advantages in ride quality.

In its default Tour driving mode, the Corvette rides like a luxury sport sedan while still handling like a mid-engine sports car. Crank it up to Sport mode, and you're roughly where the 911's default ride quality resides, with more vertical motion and louder impacts passed into the cabin. Go all the way to Track mode, and it's pretty stiff, but even then it's never harsh. Even the worst craters in the road are heard in the massive tires more than they're felt in your spine. The Porsche may be a little quicker around a track, but there's no question which car you'd rather drive home on a cruddy aggregate or a freeway cursed with mile after mile of expansion joints.

It's not just impacts, either. The Corvette allows far less engine and road noise into the cabin than the 911. There's more noise from those big tires, especially the front ones right next to your feet, but you can have a whispered conversation at 80 mph in the Corvette. You'll have to speak up a little in the Porsche.

It's just one of the ways in which the Corvette's cabin is nicer than the 911's, a sentence we feared we'd never get to write. The Corvette's notoriously cheap materials, gaping panel gaps, and persistent smell of glue have all been banished—and this was in an early-build car, no less.

The previous Corvette generation showed us Chevrolet could afford to give the car both performance and a nice interior, but the C8 has skipped straight past nice and into proper supercar territory. The leather is the best we've seen and felt in a Corvette by a wide margin, there's no cheap-looking hard plastic anywhere (well … the cupholders are a bit of a wince), and the seats (midgrade GT2s, in this case) strike a balance between comfort and lateral support that even some supercar builders don't get right.

Granted, our Corvette was a top-shelf 3LT trim level with the best interior you can yet buy for the car, but you can do that when the as-tested price is a Silverado less than the 911—which had zero interior dress-up options, at that. Sure, Porsche will wrap the air vent blades in leather if you put enough zeroes on the check, but out of the box, it's a stark field of dark grays and blacks all finished in varying grades of plastic and piano black. Our Carrera didn't even have power seats.

In judging these cars, we kept coming back to priority. If it's the ultimate driving experience you're after, the feeling of car and driver as one, the Porsche is worth those extra as-tested $34,335. If those extra tenths on a racetrack matter most, the Porsche is also worth the money. But even if this is the lens you judge sports cars through, Porsche should still be looking over its shoulder.

It's always been easy to write off the Corvette as producing big numbers with all the grace of 12-pound sledge. No more. If you're willing to give up a little bit of steering feel and learn to work around the brake pedal, you'll find far more car to love in the Corvette. Performance per dollar used to be an excuse to brush away the Corvette's shortcomings. Now, it's a virtue. Exotic and attainable, it finally punches above its weight class in every category, not just one. When it's this damn good, money matters. The Corvette isn't good enough for the price. It's unbeatable.

Still, Chevy admits that the DCT is heavier than both of the transmissions it replaces—the torque-convertor automatic and the manual—and contributes to the new car's extra mass.

The new engine's larger liquid-to-liquid oil cooler, more-robust lubrication system, and extra radiator (three total on the Z51) undoubtedly add weight. The mid-engine's inherent rear-heavy weight distribution (39.4/60.6 percent front/rear versus 49.4/50.1 for the C7), improves launch traction dramatically. Factor-in a top-notch launch-control system and, despite the added weight, the C8 posts a dramatically improved zero-to-60-mph time of 2.8 seconds. It's the quickest Corvette we've ever tested, even beating out the C7 ZR1 at 3.0 seconds.

The C8 Corvette is also one of the largest mid-engine cars, measuring some 5.3 inches longer and 2.2 inches wider than the now-obsolete C7. Those increased dimensions, including a half-inch longer wheelbase, are obvious sources of added heft.

Other incremental size changes that translate to increased weight on the 2020 Corvette are wider rear wheels and larger rear brake rotors. Every C8 Stingray has a set of 305/35R-20 rollers out back mounted on 11-inch-wide wheels—1 inch wider than those on the C7 Stingray—that are quantifiably heavier. Likewise, the C8's rear brake rotors grow by 0.3 inches on the base Stingray and 0.5 with the Z51 package to take advantage of the rear-biased weight distribution.[/quote

Chevy also cited the C8's new suspension setup as a factor for it being heavier. For those who forgot, the outgoing Corvette rode on composite transverse leaf springs. Its mid-engine replacement features coil-over shocks sandwiched by control arms at all four corners, which improve ride and handling but add weight.

Finally, since the 2020 Corvette will be the first to offer right-hand drive for global markets, it must also meet broader regulatory requirements. Chevy says this requires certain design elements and more components that in turn add more mass.

kevm14 wrote: Wed Oct 16, 2019 6:37 am This also would have been an opportune time to mention alignment stuff. But nothing. How about tests between stock alignment and track alignment? I hope someone does this anyway...