2010 Chevrolet Corvette ZR1 & 2007 Chevrolet Corvette Z06 - Two Sides To The Story

In which we learn that maximizing a ZR1’s racetrack performance requires more than a simple engine upgrade

Jack Criswell Aug 22, 2011 0 Comment(s)
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To paraphrase Muhammad Ali, GM shook up the world with the ZR1. Corvettes have always been world class, but the ZR1, bulging with 133 more horsepower than the already-formidable Z06, was in a class by itself. To prove it, Corvette Racing driver Jan Magnussen lapped Germany’s Nürburgring in a ZR1 at 7:22.4, beating the Ferrari Enzo, the Pagani Zonda F Clubsport, and the Maserati MC12. Take that, world!

Vemp 1111 01 O 2010 Chevrolet Corvette ZR1 Front 2/9

Thanks to its carbon-intensive construction and 638hp LS9 engine, the ZR1 hits 60 mph in 3.4 seconds and reaches a top speed of 205 mph. A Magnetic Selective Ride Control suspension allows the use of lower spring rates than are employed on the Z06, making the new King of the Hill both more responsive and more comfortable to drive than its recently deposed predecessor. Best of all, the ZR1 carries a bargain price (for an exotic) of only $103,000. Could it get any better?

Second-generation Corvette enthusiast Mark Osborne certainly thought so. After trading in his beloved Z06 on a new ZR1, he embarked upon a series of modifications that culminated in shipping the car to Lingenfelter Performance Engineering (LPE) in Decatur, Indiana.

Osborne isn’t your typical performance junkie: he likes show cars. He wanted to make this one stand out, so he first sent it to Steve Ray at Airbrush Incorporated for “something menacing.” Next, he added more menace with black-chrome wheels; tinted windows, lights, and markers; polished engine pieces; and a variety of subtle touches, all expertly done. Notice, for example, the additional carbon-fiber trim pieces, which were done by Osborne’s own company, Southern Coating and Nameplate Inc.

But Osborne knew the raison d’être of the ZR1 was performance, so off the car went to Lingenfelter, which added a 2.60-inch supercharger pulley, a 100mm double-bearing idler assembly, a solid supercharger-isolator coupling, an air-intake system, and a 160-degree thermostat—all blended together in a nice, balanced package that only improves upon the LS9’s existing strengths.

Vemp 1111 02 O 2010 Chevrolet Corvette ZR1 LS9 3/9

Before doing the modifications, Osborne had the then-1,000-mile car dyno tested. It registered 525 horses and 510 lb-ft of torque at the rear wheels. With the LPE bits and a few other small items installed (see the accompanying Spec Sheet), those numbers jumped to a downright alarming 600 rwhp and 580 rwtq.

“The car is completely different, and the throttle response is breathtaking, to say the least,” he says. “It was bad when it was stock, and now the only way to describe it was nasty and mean. It will burn the Michelin Pilot Sport PS2s till close to 90 mph and into Third gear. The supercharger comes alive a lot quicker, and you have to roll into the throttle to even consider getting traction.”

While that level of speed would be enough for most, Osborne yearned for even more. But this time the focus would be on the machine behind the wheel, rather than on the car itself. Specifically, he sought out some first-class driver training from David and Tom Leonard of SpeedSouth Active Power (www.speedsouth.com).

A performance-tuning and race shop in Pelham, Alabama, SpeedSouth’s Z06 (sidebar) won First overall at NASA’s Road Atlanta event last December, and followed up that performance with a First in class at the PBOC’s Sebring race in January, beating Ferraris and Porsches in the process. The next month it won First overall with NARRA and PBOC, then took First in class again in a race the very next day. So maybe these guys know a few things about making Corvettes faster.

Vemp 1111 03 O 2010 Chevrolet Corvette ZR1 Mark Osborne And David 4/9

Osborne had never been on a track before, but he drove the ZR1 on the seven-hour trip from his home in Arkansas to Barber Motorsports Park in Birmingham, Alabama. There, he spent a weekend with David Leonard, learning how to handle this new beast on Barber’s 2.38-mile, 17-turn road course. As it turned out, it may have been the smartest thing he’s done yet with the car.

Despite mostly wet conditions, Leonard was able to take Osborne and the ZR1 out several times. Then, he took out the SpeedSouth Z06, with Osborne following along in the ZR1. Both men exhibited remarkable restraint by motoring along for our photographer at merely “really fast” speeds. With so much horsepower on such a beautiful track, posing for a photog in a slow-moving camera vehicle must have been a challenge.

With a bona fide race driver at the helm, Osborne was stunned at his car’s true capabilities. “We could have passed in the corners!” he said afterwards. “The car felt like it was on rails. The brakes were strong, and [they] were used more on those laps than they ever had been. It was amazing how fast David was...full throttle, then on the brakes hard and back to full throttle again. If my head wasn’t pinned to the left or right, it was pinned to the back of the seat.

“You would see a car up ahead and it wasn’t [but] a few seconds before David was on the rear bumper and going for the pass. To hear the car was impressive: you could hear as soon as he touched the gas, the supercharger let out a scream, and we were gone again. When the exhaust cut-outs opened, the car sounded amazing, like it was where it needed to be every weekend…on a racetrack!”

Vemp 1111 05 O 2010 Chevrolet Corvette ZR1 PBOC 5/9

For his part, Leonard could tell straightaway that Osborne had more experience at car shows than on racetracks. The new ZR1 owner was stunned to discover just how effective those carbon-ceramic brakes really were, to learn what 1g of lateral acceleration really felt like, and to experience the true capabilities of the car’s perfectly balanced suspension.

Even if Osborne never takes the next step with more instruction, he’s already a safer driver knowing that his ZR1 is essentially twice the car he thought it was. As Leonard points out, “That’s important, because guys like Mark need to know how to handle situations with all that power. Most accidents happen with other cars, so the braking and nimble turning [can help him] avoid them.”

Think of it as the “ten tenths” analogy. If a car’s maximum performance is considered ten tenths, most drivers will never experience more than about two tenths of that capability. That’s true even if the vehicle in question is a minivan. Driving instruction helps you find that fourth or sixth tenth of your car’s capability. You’ll not only double or triple your return on investment from a driving-enjoyment standpoint, you’ll be a safer driver in the process.

According to Leonard, most of his students are “gearheads, track junkies. They want to get that extra tenth.” But some of those guys can actually be a little too aggressive to learn anything. Osborne, on the other hand, was a model student, even if he was reluctant to thrash his mega-motor Corvette himself. (And who could blame him for that? His experience with the ZR1 at Barber was akin to coming home and discovering that his lovable pet dog had just disemboweled two would-be burglars. A newfound respect was clearly in order.)

Vemp 1111 06 O 2010 Chevrolet Corvette ZR1 Barber Motorsports 6/9

Which brings us to our ultimate question for Leonard: What’s the best way to maximize the performance of an already Lingenfelter-ized ZR1—or of any powerful Corvette, for that matter?

First, attend a driving school. Technique, car control, situational awareness—such things are far more valuable than a freer-flowing exhaust or a larger-diameter brake rotor.

As for mechanical modifications, the one thing you should consider doing before attending a driving school is upgrading (or at least replacing) your brake pads and fluid. As you learn to stop faster and with more control, you’ll want your brakes to be up to the task. “It doesn’t matter how fast you go, but it does matter how fast you can stop,” Leonard says.

The next way to get more performance from the typical Corvette may be less obvious: get better seats. Street-car seats, even a Corvette’s, are too loose, allowing your body to slide around in the curves. Better control from the driving position will always produce quicker lap times.

When it comes to actual performance modifications, SpeedSouth recommends removing the magnetic ride control from any Corvette that sees regular, heavy track use. “Stiffer coilovers would make for better control than the magnetic ride. That would be about $3,000. I’d also add thicker sway bars [for] another $1,500,” says Tom Leonard.

Vemp 1111 07 O 2010 Chevrolet Corvette ZR1 7/9

“But…doing that is still not as good of an investment as a track school,” notes his brother, David.

Finally, simple tuning and adjustment of the existing package can produce impressive results. SpeedSouth, for example, uses two dyno machines. One is a standard unit that checks horsepower, while the other performs all three of the most critical suspension adjustments at once: corner balancing, bumpsteer, and alignment. These settings are interdependent, so being able to do them all concurrently without jacking up the car between each step makes a balanced setup possible.

In the end, the only thing better than a modified ZR1 is a driver with equivalent performance enhancements. Only then can this vital pairing’s true potential be fully revealed.

SpeedSouth’s Z06 Track Car

You’re probably wondering, What about that SpeedSouth Z06 that’s winning all those races? The car sports a World Challenge carbon-fiber hood, a Riley rear wing, an APR splitter, a custom-built undertray from SpeedSouth Active Power, and a Racekeeper data-logging and video system. A Discovery Parts Coolsuit keeps the driver comfy behind the wheel, while a Go-Pro high-def camera captures all the action for post-race dissection. A sequential transmission is planned for the near future.

Vemp 1111 04 O 2007 Chevrolet Corvette Z06 SpeedSouth Z06 Track 8/9

More details are in the accompanying Spec Sheet, but some of the really juicy parts can’t be revealed until the end of the season. It is a race car, after all.

Honing Your Skills Behind The Wheel

SpeedSouth recommends starting with a local grassroots autocross. It teaches you car control at a low speed, typically 25 to 35 mph. There’s not much seat time, and it can be a bit humbling—especially when that kid with the hopped-up Civic laps faster than your ZR1—but these events provide invaluable experience in a comparatively safe environment. Next, check with a local Corvette or other car club to find out when it’s hosting a track school or high-performance driving event (HPDE).

Vemp 1111 08 O 2010 Chevrolet Corvette ZR1 2007 Chevrolet Corvette 9/9

Try an independent group such as NASA (www.nasaproracing.com), the PBOC (www.pbocflorida.com), or Chin Motorsports (www.chinmotorsports.com). Of these, NASA is probably the biggest group, with the most frequent schools in multiple locations.

Don’t fall for the myth that a top-dollar driving school, even one with impressive credentials, will automatically make you as good as someone who’s spent time working his or her way through these lower-level schools. “There are hosts of ‘track awareness’ issues that just cannot be taught in a short course, no matter how much you pay,” notes David Leonard.

When it comes to instructors, remember that a great driver won’t necessarily make a good teacher. If you don’t feel you’re learning enough, ask for another instructor; you won’t hurt anyone’s feelings.

Oh, and there’s no need to tip the instructor. “We love doing this, and we get free track time,” says Tom Leonard. “That’s enough.”

Spec Sheet

'10 ZR1

Owner Mark Osborne; North Little Rock, AR
Block Stock LS9 aluminum
Displacement 376 ci
Compression Ratio 9.1:1
Heads Stock LS9 aluminum
Valves Stock 2.160 titanium/1.590 sodium filled
Camshaft Stock hydraulic roller
Rocker Arms Stock 1.7-ratio
Pistons Stock forged aluminum
Crankshaft Stock forged steel
Rods Stock forged titanium
Intake Manifold LS9 supercharged with Katech intercooler and Mike Norris Motorsports ported throttle body
Fuel Pump Stock
Ignition Stock coil-on-plug
Engine Management Stock with EFI Live tuning by Gwaltney Performance Innovation
Maximum Boost 14 psi
Exhaust System Kook’s headers, Magnaflow after-cat with electric cutouts
Transmission Stock TR6060 six-speed manual with MGW shifter
Clutch Centerforce Dual Friction
Driveshaft Stock
Front Suspension Stock, lowered on factory bolts
Rear Suspension Stock, lowered on factory bolts
Front Brakes Stock carbon-ceramic 15.5-in rotors with six-piston calipers
Rear Brakes Stock carbon-ceramic 15-in rotors with four-piston calipers
Wheels ZR1-style black chrome; 10x19-in front, 12x20-in rear
Front Tires Michelin Pilot P285/30ZR19
Rear Tires Michelin Pilot P335/25ZR20
Fuel Octane 93
Current Mileage 6,000
Miles Driven Weekly Varies

Spec Sheet

'07 Z06

Owner SpeedSouth Active Power; Pelham, AL
Block LS7 aluminum
Displacement 427 ci
Compression Ratio 10.75:1
Heads LS7 aluminum
Valves Stock 2.200 titanium/1.610 sodium filled
Camshaft “Trade secret”
Rocker Arms Stock 1.8-ratio
Pistons Mahle forged aluminum
Crankshaft Lunati forged steel
Rods Lunati forged steel
Intake Manifold Stock LS7 composite
Fuel Pump Stock
Ignition “Trade secret”
Engine Management Vi PEC
Exhaust System LG Motorsports Pro Long Tube headers
Transmission Stock T-56 six-speed manual
Clutch McLeod twin-disc 8.25-in with aluminum flywheel
Driveshaft Stock with urethane couplers
Front Suspension Bilstein coilovers, LGM drop spindles, Pfadt competition sway bars
Rear Suspension Bilstein coilovers, LGM drop spindles, Pfadt competition sway bars
RearEnd OS Giken differential with stock 3.42 gears
Front Brakes Stop Tech six-piston calipers
Rear Brakes Wilwood four-piston calipers
Wheels CCW C10
Front Tires 285/660-18 Dunlop slicks
Rear Tires 310/710-18 Dunlop slicks
Fuel Octane 93
Weight 2,926 lbs
Miles Driven Weekly Weekend track use only

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