'00 Drop-Top Now A Z06 ConvertibleFrom the November, 2010 issue of Corvette Fever
By Scott Ross
Photography by Jerry HeasleyNow our spies tell us that a certain NSW Corvette Club treasurer may have a bit of a drool over this one. 
OK, long-time Vette lovers: Just how long (and how strong) has been your attraction to America's Only True Sports Car? Does it go back to the days before you could spell the word Corvette? For Dave Barkus it does.
His Vette history started long before this '00 convertible arrived at his Arvada, Colorado, home. When he was a kid, instead of saving up for a scale-model Corvette from AMT or MPC, he saved his silver for a 1:1-scale version from St. Louis Assembly. In 1970, when he was 17, he made the dream come true.
"I bought my first one in Salem, Oregon, for $1,400 cash, and I drove it all the way to Anchorage, Alaska, and back over the Alcan Highway," he recalls like it was yesterday. "It was a '64 Sting Ray convertible. It had a 365-horse 327 and 3.08 rearend gears. I was clipping 13.60's through the quarter-mile with it, in Third gear." Other than the Hooker headers and side pipes (which, he says, would burn your leg if you didn't step wide when getting out), it was stock. Dave adds that the seller had one request before he left on his 4,000-mile adventure. "He said, 'Take some pictures of it-if there's anything left of the frame when you get there!'"
Over the next four-plus decades, he's had nearly three dozen Corvettes in his garage, but not all at once. In 2002, he had a '90 C4 powered by a Lingenfelter-built stroker 383 with a Paxton supercharger, but he was looking to update to a later-generation Vette. He found a modified '00 convertible for sale in Houston, bought it, and drove it home. That's when the "fun" started.
Stock '00 Vette gauges were given the white-face treatment, then were joined by boost and air-fuel ratio gauges on the left A-pillar.
"The people who played with it in Houston weren't thinking about things like emissions," says Dave. Among other things, the car's engine control module (ECM) was in default. The exhaust system had been modified, too. "It had hollowed-out GM cats on it, which wouldn't pass emissions inspection in Colorado at all."
Dave replaced what was left of the OE catalytic converters with high-performance aftermarket versions. "The first thing that I had to do was get it legal in Colorado, because there's no air here." (Well, there is, but thanks to Denver's mile-high altitude it's quite a bit thinner than what the Vette was used to breathing in Houston.) Getting properly-functioning cats on the C5 was just one issue. Once out of default, the ECM held more horrors. "We were having problems trying to decipher all the codes that were in it," says Dave. "There were 34 different trouble codes! It was a nightmare." One of those codes was triggered by the headers on the car. "You have to take the steering column out to put these headers on, and there's a sensor there that tells the computer that you're turning," he says. "They didn't have it set right, so the computer was confused, thinking the car was turning all the time."
But that wasn't all. Not only was the ECM reporting engine trouble, it also threw codes for the automatic transaxle. "It was complaining that the transmission was slipping," Dave recalls. "The computer was reading the wrong speed that the tires were turning, so it flagged transmission slippage, which it wasn't." As Dave puts it, "To say that it was a nightmare was an understatement. We had a lot of work to do to straighten this thing out."
Chrome rollbar hoops behind each seat are the most noticeable addition to the C5's interior. If Dave wanted to drag race it, the C5 is potentially quick enough (sub-13s) to need a full rollcage, which he didn't want to install
His first stop for outside help was a GM high-performance dealer. "They told me there was nothing they could do with it, and that I needed to put it on a trailer and send it back to Houston!" Dave then turned to some friends at another GM dealer who, armed with computer savvy and the needed books and hardware, helped him get his Vette not only sorted out, but running right.
The corrective work took about a year, and then the actual fun began. "My original idea was, if there was such a thing as a Z06 convertible, that's what it would look like," Dave says. "Some people do it the other way, and take a Z06 coupe and cut the roof off it."
Dave called on Peter Cochetas at Dragon Race Engineering in Broomfield, Colorado. He added a ProCharger supercharger, while at the same time upgrading and tuning the LS1 for its power adder, which produced only 5 pounds of boost at first. "He always starts out the same way, with that and a mild tune," says Dave. "He said 'Get used to that first. If you want more, holler.'"
Nitto drag radials in back weren't OE on the '00 Z06, but they're needed now to keep it pointed the right way.
Other upgrades for the LS1 included a 95mm BBK throttle body, 38-lb/hr fuel injectors, and a Comp Cams camshaft. The heads were ported, polished, and flowed. Dave's particularly pleased with the camshaft. "I didn't want a really radical, 'whumpity-whump' camshaft, because it's an automatic," he says.
Speaking of which, the only parts of the automatic transaxle that are still anywhere close to stock are the outer case and the console-mounted shifter. "Peter said, 'With that automatic, the first time you hit that thing hard, you're just going to watch it melt onto the ground. It won't hold it, there's no way,'" Dave recalls. So the OE unit went to Art Carr Racing Transmissions, which sent back one that was, in Dave's words, "guaranteed bulletproof to 1,000 horsepower."
After the ProCharger went in, Peter let Dave know his new power adder could cause trouble in a hurry. "At that time I had BFG G-Force tires on it," Dave recalls. "He said, 'I want you to stomp the throttle from a dead stop.' I did, and I spun a 180 that completely engulfed the car in smoke. I needed my Depends!" After that, the BFGs in back were replaced by a pair of Nitto drag tires.
wo years later, Dave told Peter that he was ready for more power by turning up the boost from the ProCharger. Back to Peter's shop it went, this time for upgrades like dual fuel pumps and fuel lines, 52-lb/hr injectors, and a new supertune for the ECM. In turn, the ProCharger's output went up from 5 pounds of boost to 10, which Dave says is the limit that a production LS1 block can handle. "You can't do any more than 10 [pounds]," he says, "or you'll pick up pieces of it."
At first glance, you think you see a stock LS1. Then you see the ProCharger supercharger, the centerpiece of the engine's upgrades
Despite all that he's had done with the powertrain, Dave doesn't take his C5 to the dragstrip. "If you run 12.99 seconds or faster, they kick you to the curb without a rollcage," he says. "I'm not going to make that car look like crap with a rollcage in it. So, they won't let me run it on the strip." Dave says that his Z06 convertible is more a street stormer than a track-day runner. He says that one of his buddies, a mechanic by trade, describes the car this way: "It idles at 650 rpm and runs at 190 degrees all day long. It never gets warm, and it purrs like a kitten. Then, when you put your foot in it, it turns from Dr. Jekyll to Mr. Hyde in the blink of an eye!"
Needless to say, this is a keeper. "I love this car," Dave says. How does it compare against the sixth-generation Vette? "I've driven the C6. It's is an excellent automobile, and I'm very impressed with it. But compared to the performance of my car, which isn't stock by any means, I'd rather have my C5." Through all the modifications, it only has 16,000 miles on it.
Dave's advice is simple. "If you're going to purchase a modified Corvette, make sure you know who modified it, and if they knew what they were doing!"
Dragon Race Engineering in Broomfield, Colorado, not only bolted the ProCharger to Dave's LS1, it rebuilt and supertuned the engine to cruise like a stocker and survive 10 pounds of boost.
Alma and Dave Barkus, seen here with their '00 Z06 convertible at last summer's Vettes Over The Rockies.
Among the updates and upgrades that Dragon Race Engineering added to Dave and Alma's C5 were the pair of longitudinal red stripes over the factory black paint.
Owned by: Dave and Alma Barkus, Arvada, Colorado
BodyModified production '00 Corvette convertible
Modifications: ACI hood/front spoiler/rear spoiler, Z06-style front fender vents and front brake cooling slots
Paint: OE basecoat/clearcoat black body; stripes by Dragon Race Engineering, Broomfield, Colorado; paint prep by GM Bowling Green Assembly Plant, Bowling Green, Kentucky
ChassisFrame: Production '00 Corvette
Suspension: Production '00 Corvette
Steering: Production '00 Corvette rack-and-pinion, power-assisted
Brakes: Production '00 Corvette brakes upgraded with Baer heavy-duty slotted/ cross-drilled rotors, calipers, and pads
Wheels: OE C6 Corvette Z06
Tires: BFGoodrich G-Force 275/45ZR17 (front), Nitto NT555R 305/35ZR18 (rear)
EngineModified GM LS1
Built by: Dragon Race Engineering, Broomfield, Colorado
Modifications: ProCharger supercharger (10 psi)
Displacement: 345 cubic inches (5.7 L)
Compression ratio: 10:01
Cylinder heads: Production LS1 heads ported, polished, and CNC-flowed
Ignition: Production '00 LS1 electronic coil-on-plug
Induction: Modified production LS1 electronic fuel injection with 90mm BBK throttle body, two fuel pumps, and two fuel lines
Camshaft: Comp Cams hydraulic roller
Exhaust: 1G headers and Corsa Indy exhausts
Cooling: OE Delphi-Harrison radiator, repositioned with Dragon Race Engineering hand-made brackets for the supercharger installation
Horsepower: 620 @ 6,500 rpm (on chassis dyno)
Torque: 590 lb-ft @ 6,500 rpm (on chassis dyno)
TransmissionModified OE '00 Corvette automatic transaxle with OE shifter
Modified by: Art Carr Racing Transmissions, Abilene, Texas
Modifications: Heavy-duty internal components, 10-inch 3,400-rpm-stall torque converter
Final drive ratio: 3.42:1
InteriorModified OE '00 Corvette
Modifications: Custom chrome hoop rollbars
Seats: OE '00 Corvette, upholstered in red leather
Carpets: OE '00 Corvette nylon cut-pile
Instrumentation: OE '00 Corvette gauges (0-200 mph speedometer, 0-7,000 rpm—with 6,000-rpm redline—tach, plus ammeter, fuel level, oil pressure, and coolant temperature gauges) modified with white faces, plus A-pillar mounted supercharger gauges (boost, air/fuel ratio)
Sound system: OE '00 Corvette Delco AM/FM/CD Stereo
HVAC: OE Delphi-Harrison climate control system
