|Corvette Stingray C7 General Discussions General topics on the Corvette C7 Stingray.|
|07-17-2013, 04:32 AM||#1|
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Drives: SS 45th, Boss 302, Z51 Stingray
Join Date: May 2012
7 things you don't know about the Chevrolet Corvette Stingray
7 things you don't know about the Chevrolet Corvette Stingray
By Josh Jacquot | Edmunds.com 17Jul2013
It is amid America's worst urban decay, outside the rapidly deteriorating Packard plant on the east side of Detroit, that the 2014 Chevrolet Corvette C7's details become clear. It's here, juxtaposed against the effects of time, failure and neglect that the Stingray — possibly the greatest sign of hope the city has seen in years — begins to truly shine.
After a day spent mining the C7's engineering team for details, all those tidbits (scoops, vents, material selections and tuning choices) manifest profoundly in this glorious, blue machine. Those fine points, the ones that make or break the car, the little things that matter the most when driving it hard or just driving it home, seep out into the pothole-ridden streets in front of us.
In no particular order, here are the seven best:
According to Tadge Juechter, Corvette chief engineer, the Corvette development team bought only a single car against which to benchmark the C7 Corvette: some bizarre, rear-engine German machine. GM's 911 Carrera S is fitted with a PDK transmission and carried a price tag of about $120,000, nearly twice that of a Corvette. Juechter begrudgingly admits it's a nice car, that it performs and that it's efficient, but isn't shy about pointing out his car's 60-horsepower advantage and near-equal weight. Never mind the price.
Integrated Tire Temperature/Chassis Controls
Chevy uses the tire temperature data available through the C7's tire pressure sensors to more carefully control its ABS and electronic differential. Because the pressure sensors don't measure tire temperature directly (they actually measure the temperature of the TPMS sensor's microprocessor), it's not a perfect science, but it is one that data modeling can largely overcome. And it's one more piece of information that can be utilized to enhance the driving experience.
Tire temps are split into three categories: cold (below 45 degrees), warm (45-115 degrees) and hot (above 115 degrees). In "cold" mode ABS intervenes sooner and more progressively, while the differential is more aggressive to limit inside wheelspin. As temps increase, ABS control intervenes later and becomes more lenient, while differential locking ramps up more slowly.
Faster Than a C6 Grand Sport
Chevy announced weeks ago that the Corvette C7's official lap time at the Virginia International Raceway Grand Course is 2:51.8. What Chevy didn't tell you is that the outgoing C6 Grand Sport model (fitted with larger 275mm front and 325mm rear rubber and weighing 60 or 70 pounds less) is slower around the same track.
Its lap time was in the 2-minute, 54-second range at VIR. The current Z06 runs a 2:49.
Booms When You Want Them, Silence When You Don't
Every 2014 Chevrolet Corvette C7 is fitted with active noise cancellation that utilizes the car's audio system to diminish unwanted road and tire noise. A 14-liter bass enclosure built into the car's rear bulkhead enhances the booms you want and cancels the ones you don't. The C7's optional 10-speaker Bose audio system comes with two subwoofers.
"No Corvette has ever boomed like this one," says Juechter. Seriously. He really said that.
PTM Is Faster Than You
Alex MacDonald is the chassis control engineer who calibrated the C7's Performance Traction Management system. After hundreds of laps around the Milford Road Course (also known as the Lutz ring) at GM's Milford Proving Ground, he's quicker using PTM 5 (the most aggressive mode) than he is with the system fully defeated.
Even Jim Mero, the ride/handling performance engineer responsible for all of the Corvette's official lap times, says the system is virtually unbeatable. Mero used PTM in the C6 ZR1 to set that car's 7-minute, 19-second lap time at the Nurburgring and admits he hasn't tried to beat PTM on the Lutz ring, but that it would be difficult.
According to MacDonald he knows he's got the calibration perfect — and he's got the data to back this up — when Mero complains that it's just barely slowing him down. "That's where the calibration needs to be for the best corner exit speed," says MacDonald.
24-Hour Durability Test
Before the 2014 Chevrolet Corvette C7 goes to production, it must pass a 24-hour durability test in which the vehicle performance integration team changes only the tires and brakes. Performed on the Lutz Ring at GM's Milford Proving Ground, the test is to prove the thermal stability of the car's subsystems.
Engine coolant and oil temps as well as transmission fluid and differential fluid are monitored to be certain they stay within a life-permitting range. "This is basically a test of the car's thermal stability," says MacDonald. The test is run over the course of six days using four tanks of fuel per day, partly because the heat cycling is harder on equipment than doing it over 24 consecutive hours. Each tank, when the car is driven at 10/10ths, is consumed in an hour.
Michelin Pilot Super Sport ZP
Ask Jim Mero what the best part of a Z51 Stingray is and he says it's the tires. According to Michelin North America's Lee Willard, lead development engineer for the new Corvette tire, the Pilot Super Sport ZP is a hybrid tire that utilizes technologies from both the Pilot Super Sport line of ultrahigh-performance tires and the Pilot Sport Cup DOT race tire currently optional on C6 Corvettes.
Says Mero: "The tire has high limits but also lots of latitude." And by latitude Mero means the tire (at freezing or below air temps) only needs one lap to reach its full ability on a dry track. And thanks to dual compounds and asymmetric sidewalls, it outperforms the outgoing standard-fitment tire on the Corvette in every area, including wear.
My pair of rivals and a Z51...
Red/Blk, 2LT Red, 7spd/Z51/MSRC/NPP/Nav/FAY/Blk rims/Red brks/Z51 caps/Splash grds... next up, the Z06!