The name Callaway is not typically foreign to performance enthusiasts although they may not have heard of Callaway Competition. The Leingarten, Germany-based division of Callaway has been tearing up tracks in Europe since 1993, the most recent endeavors contested in a string of Corvettes.
Callaway C7 GT3-R
Development of the Callaway Corvette C7 GT3-R began in mid-2014 under the supervision of Ernst Wöhr and Giovanni Ciccone, with technically-relevant parts designed by Mike Gramke and Uwe Hoffmann. This latest creation is based on a factory chassis of a C7 Corvette.
From there, the team completely disassembles the car, to be rebuilt using upgrades engineered by Callaway Competition. We asked Callaway Cars’ Mike Zoner about some of the changes the car undergoes. The most obvious difference is the car’s bodywork, and when asked, Mike clarifies where old and new meet by simply saying, “the rear fascia is original.” In fact, the only stock components retained from the Corvette C7 are the chassis, the lower control arms, the upper half of the rear bumper, and the tail lights.
From there, the modifications flow fast and steady, half of the flooring and the rest of the Paul Deutschman (Callaway’s designer of the past 30 years) body is new, comprised of carbon fiber for weight savings and strength. New upper control arms, shocks (coilovers), brakes and bearing hub assemblies are upgraded in an attempt to gain the adjustability and durability necessary to win races.
To further the racing pedigree, a complete air jacking system is included, as well as a center wheel locking system at each corner for quick tire/wheel changes. Of course, safety is a major concern and a complete caged assembly rounds out the chassis to protect the driver and give the rigidity necessary for accurate handling. An integral fire suppression system stands guard in case this hot rod ever becomes too hot to handle.
The 6.2L (381cid) LS-based, all-aluminum V8 is speed-density calibrated via a Bosch engine management system to run on 98-octane fuel and encompasses 540-600 horsepower, depending on the intake restrictor size used. It features a dry-sump oiling system and utilizes drive-by-wire technology. Behind that, a rear-mounted X-Trac 6-speed sequential gearbox is shifted by a MEGA-line paddle shifter mounted to the vessel’s tiller. The racing-focused steering wheel features controls for adjusting the ABS, brake bias, traction control, power steering assistance level, launch control as well as pit speed regulation and pit timing.
The Road To North America
German-based Callaway Competition has been racing its C7 GT3-R in Europe for years and they have a bevy of championship trophies to show for it. The European branch continues to campaign its own GT3 race team and sell Corvette GT3 race cars and support parts and equipment to leading race teams throughout Europe. But, Chevrolet has expanded Callaway’s exclusive authorization to homologate, construct and sell Corvette GT3 race cars worldwide, including North America. That opened the door to compete here in the States in the Pirelli World-Challenge series and we visited with Callaway Competition USA during the PWC races in St. Petersburg, Florida.
I am thrilled to be able to please the Corvette fan base with some great racing. – Team Owner, Reeves Callaway
Unlike the ALMS’ 12 or 24-hour races with several car classes on-track at the same time, the PWC is comprised of several shorter sprint races approximately 50 minutes in duration. The Callaway GT3-R races in the GT class and is driven by long-time Callaway driver Daniel Keilwitz, from Germany. Both he and the Callaway GT3-R are setting foot on American soil for the first time and they are leaving a notable footprint in the process.
His introduction to US racing was held one week before the St. Pete races, where the Callaway team unloaded their GT3-R at the famed racetrack in nearby Sebring, Florida for a brief testing session. Team owner, Reeves Callaway described the feeling following the testing session. “We accomplished everything we set out to do at the Sebring International Raceway test, both with the Corvette and Daniel’s first time on track in the US.”
Reportedly, Daniel and the Corvette’s lap times around the 3.74-mile road course were quite satisfactory and expectations were high going in to this weekend’s event. We asked Callaway Competition General Manager Ernst Wöhr about any differences in setting up the car between American race courses and those they are so accustomed to in Europe. “We have to learn the proper setup. We spent the day at Sebring, which is a rough track, rougher than we are used to. Even so, we didn’t need to change much.”
While drastic changes were avoided, the devil is in the details and there were several test sessions in St. Pete to tune the devil out of the car’s suspension. Changes and checking are all part of setting up for racing, tire pressures are checked religiously and the car’s alignment is verified each time it leaves and re-enters the Callaway pit area.
Setting up the car is mechanical, the playground of engineers and technicians. Getting Daniel ready for a new course he’s never driven on before is entirely upon his shoulders. He explains, “Now it’s on me to learn the track. I like street circuits and I’ve watched a lot of onboard videos to prepare for this one. In my mind, I have the track down, but now it’s time to see it in person.”
Daniel got to see every square inch of the course during the practice sessions and qualifying and as evidenced by his lap times, he was quite prepared to wrest with the best on his first foray into the PWC. They say you’ll never learn where the limit is, until you step over it and Daniel gingerly stepped over that line and tapped the wall with the right front corner during qualifying. With a few scuffs on the front fender and a quick splitter change, the Callaway GT3-R and a finely-calibrated Daniel were ready for their first race in America.
Racing in the PWC is a sprint-style race. You’ve got a dozen or so competitors all vying for the same top three steps of the podium and a limited amount of time to get there. All PWC GT races are over in less than an hour and St. Pete had a race on Saturday and another on Sunday. For Saturday’s race, Daniel’s lap times garnered him a third-place start on the grid. He didn’t stay there long and before the first turn, he was in the lead. Getting to the turn first is good, but getting out of the turn first is better.
Stringing The Car
Consistency is key in racing. Doing the same thing as fast as you can, again and again is the only way to stay ahead. When setting up a chassis, you need to know what works and you need to know that it will stay that way until you make another adjustment. If not, you’ll soon wind up chasing your tail.
Every time the car moved in or out of the Callaway pits, the team would “string the car.” This meant running strings down the sides of the car and doing preliminary checks to see if something had changed during the action. This was done as soon as the car returned and before any adjustments were made.
When Daniel bumped the wall, the strings told the tale. While you won’t see any caster or camber changes, checking the toe on the front and rear wheels is a good indicator of the stability of the suspension geometry.
With only fifteen minutes remaining, Keilwitz had worked his way up to fourth position, behind the #2 Mercedes driven by Daniel Morad. Moving up through the field meant the drivers were getting progressively faster and the remainder of the race would find these two helmsmen doing their best to out-drive the other. In the end, time won out and the #26 Corvette would suffice with a fourth-place finish for the first race on the tight, twisting course in downtown St. Pete. An up-side being that Daniel’s fastest lap gained him a second-place start for the following day’s race grid.
Being in second when the flag falls is good, but there are a lot of laps to try and keep that position. Daniel’s start for the second day wasn’t a re-play of race one. Expecting tire pressures to increase during the race, Team Callaway began with lower tire pressures, hoping to hit that sweet-spot once the tires were up to temperature. That meant sacrificing traction for the start. Daniel explains, “I had wheel spin at the green flag and lost two positions to the other guys. We knew if we played it cool, I’d be faster once we came up to temperature.”
That he was. In working his way within inches behind the leading Scott Hargrove in the No. 96 Porsche, Daniel and his Corvette cut the fastest lap time for the race. In a sprint race, how you finish is just as important as how you begin and with only 50-minutes to find your way to the top spot on the podium, all it takes is for a car to get tangled up in a wall or another car and many precious minutes could be lost under a yellow or red flag.
Two cautions were thrown during the last 30 minutes of racing and then finally, with less than 10-minutes remaining, the red flag was thrown due to the No. 9 K-PAX Racing Bentley Continental GT3 going head-long into the tire barrier at speed. The resulting cleanup would consume the rest of the time on the clock and Keilwitz and the entire Callaway Competition USA team would need to settle with a second-place finish.
The fans are great here. It’s a little different for me but I really like to race here, so it’s a good first adventure for me. Unfortunately, we had the red flag. I think I could have managed to go a little bit faster, but I waited until the end. Now we’ll never know what could have happened. – Callaway driver, Daniel Keilwitz
Keeping a long-term focus during a sprint race is not easy but team owner Reeves Callaway said it best, “I’m happy to see the front-running performance from Europe continued for our North American debut. We had two really good, tough races and Daniel was able to show his skills against a very talented field of drivers. I am thrilled to be able to please the Corvette fan base with some great racing.” While the win was certainly only a few laps away, the Callaway Competition USA team celebrated a job well done, and the first podium in U.S. competition for the car.
The Pirelli World Challenge will compete next at the Circuit of the Americas in Austin, Texas for Rounds 1 & 2 of the SprintX championship (March 23-25), a 60-minute race in which two drivers share the driving duties for the same car. Enthusiasts who can’t attend the event can view online at the World Challenge website and you can learn more about the Callaway GT3-R at Callaway Competition’s website. Keep your eye on Team Callaway and the GT3-R Corvette, as you can rest assured, all of the competition surely will be doing just that!