Eateries have names like "Pit Stop," and service stations are called "Raceways." Diehard race fans fan the area, taking two-wheeled corners while clutching cartoon tour maps and Lowe's Motor Speedway souvenirs.

The locals here are as hospitable as Southern folk are, but their drawl is slightly terse—those involved in the racing industry here are as tight-lipped as a small-mouth bass clamping down on a worm.

Race cars cross the finish line only fractions of a second apart. Shaving those all-important seconds begins long before the drivers scurry through the windows of their rides. A finely engineered and manufactured race car can be the difference between winning a race and placing or being shut out of the lead lap, and so "speed secrets" are closely guarded.

One racing company is not afraid of sharing one of its "secrets"—the use of a Flow International ultrahigh-pressure (UHP) Dynamic Waterjet® machine.

Weekly Races, Weekly Deadlines

NASCAR Nextel® Cup schedules 38 races a year, from February through November. For premier racing companies like Joe Gibbs Racing, Huntersville, N.C., that means production schedules are as tight as track turns at Bristol.

Joe Gibbs Racing sports three Nextel Cup teams, winning three Cup championships in a seven-year period. It also has two Busch series teams and manages diversity and driver development programs. It is the race team com pany of Washington Redskins head coach Joe Gibbs. Its Nextel Cup drivers Tony Stewart, Denny Hamlin, and J.J. Yeley are well-known race stars.

"Our deadlines are weekly, and every week there's a new race," said David Holden, research and development engineer, Joe Gibbs Racing.

Race cars burn through an engine every race, as well as other parts that must be replaced. "All we get out of a motor is just one race," Holden said. "So we'll manufacture in the range of 400 motors this year, and they cost $60,000 apiece."

Being Ready for Crashes. Intensifying the need for an ample supply of parts is that racetrack crashes are as common as tire changes.

"If you have a crash on the racetrack and you damage one of the parts that is your speed secret, you've got to have more," Holden said.

"If you go to a race at Bristol and then to a race at Martinsville and then to a test at Richmond, you could potentially crash at all of those events. You have to be prepared for that worst-case scenario, and the worst-case scenario happens every now and then. Ideally, we'd love to have 50 parts, but if we can only have six, we'll take six," Holden said.

Putting supposition to the metal, in the Daytona season opener, Tony Stewart's car was wrecked after leading the race, and Denny Hamlin's car was damaged. Still, their cars had to be race-ready by the next weekend.

Gaining Competitive Edge. Too, there is constant pressure to gain a competitive edge every week that will rev up horsepower or improve downforce to make laptimes, Holden said.

"Every time we come up with a part development that we think is going to make the race car go faster, we've got to figure out how to manufacture however many of them we need for that weekend within a day or two to get those developments on the race cars," Holden said.

Mark Bringle, CNC and quality control manager, elaborated. "I call it the race between races, because, literally, it is a race to get these concepts to the cars as quickly as possible. We'll do testing over the weekend; Monday we'll see blueprints; and trucks leave with new parts on Thursday," he said.

"Our guys are constantly preparing cars for the weekend after next and the weekend after next and the weekend after next," Holden said.

Deadlines to Finish Lines

The midnight oil at Joe Gibbs burns hotter than motor oil. A staff of 24 engineers, 50 body fabricators, 120 mechanics in the chassis shop, 51 engine builders in the engine shop, and 29 CNC machinists work in two shifts, from 6 a.m. to 2 a.m., to try to help keep the race cars on track. Altogether, more than 400 people are employed at the company, in cluding pilots, truck drivers, and administrators.

Even with the large staff and 24 CNC milling machines, rapid prototyping, laser cutting machinery, and other equipment in its technology center, the company had difficulty fulfilling all the parts needs for the cars. "We still needed capacity," Bringle added. "We were overloading our mills with work. There was not enough time on the mills to hit production deadlines."

Many of the materials needing to be cut, such as stainless steel—and some materials he can't mention—are very hard to machine, Bringle said. "With the properties of the stainless, you can only turn your rpms and your feed rate to the certain expectation of the tooling. Just roughing out the perimeter of an exhaust flange took a little over an hour on the mill."

To make some of the plate-thick components, the race company was purchasing torch-cut or laser-cut plate blanks, Bringle said. "The problem with 1-inch-thick plate that's been torch-cut is the edges are really nasty and very hard. So trying to machine a piece out of that torch-cut stock part is a terrible task."

To avoid complications with flame-cut parts, the company sourced waterjet-cut parts from an outside vendor. But relying heavily on an outside vendor created drag on the schedule.

"We've got a very talented engineering group here coming out with a lot of great ideas," said Bringle. "So when you find a niche or something that will give you a competitive edge for that weekend, the crew chiefs don't want it sitting on the table for four weeks as you might if you're working with an outside company. They want it on the car that weekend."

Smoothing Speed Bumps With a Waterjet

Timesaver. New parts often have to be re-engineered and refabricated. "When we first developed a motor plate [see Figure 2], we had some fit-up issues to deal with, so it needed several revisions," Holden said.

"Being able to use the waterjet to feed the milling machine was a huge timesaver for us," Holden said. "We took that motor plate out of the milling side and put it on the Flow waterjet and then did finish machining in the mills. So that really freed up mill capacity."

The 1/2-inch-thick aluminum 6061 motor plate, or engine plate, which supports the chassis, is cut on the waterjet in 11 minutes. A 0.050-in. stock allowance is left for a finish milling step, which takes 45 minutes. "Basically, we do a skim cut, just taking off the last little bit, and then the part's finished," Holden said. "We reduced mill time by 40 minutes per part."

An upper control arm plate that took 55 minutes to cut on a milling machine out of cold-rolled barstock is now roughed out of hot-rolled A36 plate on the waterjet in seven minutes and milled for eight minutes, Holden said. "Our initial run was 50; we calculated that we basically found an entire week's worth of mill time on that job, so that was huge for us."

Figure 3
Cutting the perimeter of the stainless steel
exhaust flange and then mill-finishing it cut 45
minutes out of a two-hour cycle time.

Making Stainless Painless. Cut ting the perimeter of the stainless steel exhaust flange took only 10 minutes (see Figure 3). "The waterjet doesn't care how hard it is or how thick it is. It's just easier to cut stainless on it," Bringle said. "We cut about 45 minutes out of a two-hour cycle time."

"Having more parts available because you've freed up mill time allows you to have parts prepped for the cars that are going in the following weekend," Holden said.

Cold Cut, Not Torched. Now the company blanks thick plate parts on its own waterjet, Bringle said. "There's no heat-affected zone and there's no slag, so we can just go and mill it as if it were virgin material with no effort."

Versatility Enhances Speed. Waterjet's capability to cut different materials and thicknesses is extremely valuable, Holden said. "We use the waterjet for a lot of the variety of materials we use, from steels to aluminum, stainless steel, titanium, INCONEL® [alloys], and plastics … about anything you can imagine you need to cut. Our waterjet is an all-around versatile team player that cuts about anything we need to do," he said.

"So we've got the operator already familiar with the programming interface for one material, and we've got the commonality of all the consumables," Holden said. "The operator aspect is big because the staff on both shifts run the waterjet. So if you had to cross-train multiple operators to cut different materials on multiple machines, it would get more and more confusing to train them."

Waterjet-finished Cut. The company waterjet-cuts more than 400 different parts, and about half do not require milling, according to Nathan Kirkman, who operates the Flow waterjet.

"We run typical tolerances of 0.002 inch on this machine, which allows us to do almost mill quality, and many of the parts are basically finished the way they are," Kirkman said, especially if they're not interlocking or sliding parts.

"We leave a waterjet edge on a lot of the stainless or INCONEL exhaust flanges, rather than going around them with a CNC?end mill," Kirkman said.

Flowing With the Changes

After the waterjet was installed, training was seamless, in part because some employees had used waterjet technology before, and in part because the machines are designed to be simple to learn and use. "It's a totally user-friendly software package and machine. We had it up and running the day it was installed," Holden said.


Figure 4
As the race car bodies develop and change,
the skirts change to get the optimal length.
They are now cut on a waterjet.

Being able to make program changes on the waterjet easily is important for cutting parts that often require several iterations, Bringle said. "It seems we're always making a skirt change. We'll make wind tunnel changes or vehicle changes to get more downforce. As the bodies develop and change, the skirts change to get the optimal length [see Figure 4]. The guys who hang the bodies always had trimmed those out by hand, and it was very, very time-consuming.

"Now we'll constantly go back in and revise that program on the waterjet, and since there's no setup time involved, we just pop it on our machine and make more parts," Bringle said.

Kirkman can operate the waterjet on-the-fly—programming it while parts are being cut.

"This is a 9-1-1 machine," Kirkman said. "Guys will come down here and they'll say, ‘I need something right now,' because they know I can do it without any setup. This is where you go when you want something quickly. You don't go to the milling machine."

It takes anywhere from 15 minutes to 30 minutes to program anything 2-D that is needed, Kirkman said. "Somebody can bring me a basic print like I have here, and I can turn this part around in a matter of 45 minutes—and that's pulling up the program, setting the machine up, and running it."

The machine also has 3-D programming capabilities, Kirkman said. "This is a big step for waterjets. It used to be just 2-D stuff. Now it can do angulars and different 3-D components like that."

The 3-D programming is a little more complicated, he said. "An engineer will submit a drawing, and I'll pull it up on the software, and a lot of times I have to modify their drawing, go in there and do my own 3-D modeling for my software."

Final Lap

Holden and Bringle said they thrive on being able to see the results of their developments every weekend. "It's being able to have that evaluation, that constant feedback—we won the race, we were second, third, fourth, we did a really good job this weekend. Other times it's really demoralizing when you realize that you've got a lot of development that you've got to do to make up for," Holden said.

"A couple of years ago, we went out to this test in Las Vegas, and we were terrible—completely terrible," Holden said. "And we all buttoned down and came out with all these new developments, new parts. In 2005 we won the championship. In 2006 we were third in the championship."

"I can't say which race, but we had some concepts that we were trying to get to the car, and the waterjet was very instrumental in doing that—talk about the competitive edge—we had a stretch there where we knocked out five wins in eight races with Tony Stewart," Bringle said.

"So we've picked up our level of competition," Holden said. "We wouldn't be able to do that without the technologies available and without the people in our technology center."

"Something else that's pretty amazing is that there are a lot of guys who go to the track every weekend, and they absolutely know they're not going to win," Bringle said. "If you look at all the technologies that go into a race car, and at everything that could go wrong … for us to actually win a race, it's mind-boggling. To win three championships in the last seven years … there are no words to describe it."

Senior Associate Editor Kate Bachman can be reached at kateb@thefabricator,com. Robert Runkle contributed to this article. Photos courtesy of Flow International except where noted.

Joe Gibbs Racing, 13415 Reese Blvd. W, Huntersville, NC 28078, 704-944-5467, www.joegibbsracing.com

Flow International Corp., 23500 64th Ave. S, Kent, WA 98032, 253-850-3500, info@flowcorp.com, www.flowcorp.com