Bob Bondurant once told us that last year's race car is the oldest car in the world. The reference to physical age is clearly a metaphor for the evolution of technology in road racing, but there is another meaning: Buying last year's race car is cheaper than building your own. If you don't have a specific vision for how the car needs to look, you can get a used race car for a third of the price of doing it yourself. As with anything, there are traps. The wrong 'cage or wrong combination of parts can undo the savings and stick you with junk. We recommend going to your local racetrack and hiring the tech inspector or a known chassis builder as a consultant who will go with you to look at used race cars. That and following the advice below will keep you from getting a bad deal when buying a used race car. Used Race Cars: The 'Cage A rollcage is required for any full- bodied drag race car with an unaltered firewall and floor that runs quicker than 10.00 or faster than 135 mph in a quarter-mile. Convertibles or open- bodied cars require a 'cage if quicker than 10.99. The rollcage must have a chassis inspection every three years and have an NHRA sticker before it will pass tech, making it the most important part of the car. If it is improperly installed, is the wrong size, or is not built for the speeds you want to run, it has to be removed from the car and replaced. We spoke to NHRA tech inspector Pat Cvengros about what to look for before you make the deal on a used race car and had him inspect our chassis for certification. "The most common problem with used race cars are missing D-bars and the main hoop or A-pillar bars that are the wrong size or thickness," Cvengros says. The main hoop is the portion of the 'cage that connects the frame together and protects the driver from a rollover. It needs to be placed above and behind the helmet when the driver is belted into the car and must include a crossbar that is no more than 4 inches below the driver's shoulders. The D-bars are welded to the main hoop and vertically angled toward the center of the car. They are required only when the main hoop is welded to plates on the floor instead of to the car's original frame or a crossmember. If the D-bars are incorrect, they can be added or fixed easily. The main hoop also needs to have rear braces that must be a minimum of 30 degrees from vertical and welded in and a door bar that passes the driver at a midpoint between the shoulder and elbow. These parts constitute a rollbar for 10.00-and-slower full-bodied cars and form the basic structure for a rollcage. Cars faster than 10.00 need A-pillar bars that run along the roof of the car and connect to the sidebar at its base and along the top of the windshield. These parts complete the structure and protect the driver from an impact from any angle. Both the A- pillar and main hoop need to have a minimum of 1-5/8 inch od with a material thickness of no less than 0.083 inch for chromoly or 0.118 inch for mild steel. Fixing missing or incorrect D-bars is easy, but if either the A-pillar bars or main hoop are too small or too thin, they need to be totally removed and replaced. That's a deal breaker. Used Race Cars: Welds And Workmanship All the monkey bars in the universe aren't going to save you if the welds break. The NHRA requires that the welds not be porous (aka bird poop), and they can't be ground down or caked with Bondo and painted. They also require chromoly tubing to be TIG-welded and mild steel to be MIG-welded. When looking used race cars, be sure to have the welds checked by someone who knows what they are looking at. Finally, take a look at the race car structure as a whole. A good rollcage has bars that are as high as possible in the car and tied into the load points of the suspension. It will also be built as far forward as possible with a front crossbar that is behind the dash and up near the cowl. Although not required by the rules, tube gussets and crossmembers keep the car rigid and the suspension behavior consistent while further protecting the driver in the case of side impact. Bring a guy, take your time, and buy a good car. Then take your car to a track or call the NHRA to have a chassis inspector sent out to certify the chassis. Steady readers might recognize our '71 Dodge Demon that we found on the Internet and dragged back home to teach you how to build a fast four-link drag car. It already had a back-half kit, so we finished the chassis with a Chris Alston's front frameclip and just plugged in an eBay 5.7 Hemi. Steady readers might recognize our '71 Dodge Demon that we found on the Internet and dragg In this photo you can see the main hoop, crossbar, and rear braces that are more than 30 degrees from vertical. Anything less and the hoop can collapse on impact. The X is not necessary but adds strength to the chassis by tying the suspension mounting positions to the rest of the 'cage. The rear braces must be the same diameter and wall thickness as the main hoop. In this photo you can see the main hoop, crossbar, and rear braces that are more than 30 d In this photo, you can see the D-bars that connect the crossbar to the frame of the car. In this case, it is a Chris Alston's back half with its own frame, but in a normal, unibody car it would be connected to the subframe. The door bars can be removable, but the crossbar can't. Note that the A-pillar bar is nearly invisible against the roof of the car. In this photo, you can see the D-bars that connect the crossbar to the frame of the car. I The rear braces usually run through the package tray to the upper shock mounts. In the Demon, they run straight down to an extra crossmember on the back half. In a street car, they can be countered to the roof so they can’t be seen. The rear braces usually run through the package tray to the upper shock mounts. In the Dem This is an example of both good workmanship and extra effort from the chassis builder. This tube gusset will maintain the integrity of the frame and the 'cage under acceleration and unfortunate deceleration. The triangle is the strongest shape next to the column (arches and circles included). This is an example of both good workmanship and extra effort from the chassis builder. Thi Here you can see where the A-pillar bar disappears into the dash to connect to the dash bar. It is hidden away so it won't break your knees in an accident. It looks better, too. Behind where the passenger seat belongs, you can see at least three triangles. Here you can see where the A-pillar bar disappears into the dash to connect to the dash ba This photo is to show you the dashbar running behind the glovebox. In this photo you can see the rear braces as they run through the package tray and into the trunk to tie into the suspension. In this photo you can see the rear braces as they run through the package tray and into th Here are the front frame braces that will be connected to the front frameclip. Bars outside the main hoop can be 1-1⁄4 inches instead of 1-5⁄8 inches. These braces are tied into the dash bar and A-pillar bars inside the car. Here are the front frame braces that will be connected to the front frameclip. Bars outsid Cvengros brought a simple go/no-go gauge to the shop to check the outside diameter of the bars in the ’cage. The main hoop, A-pillar, and door bars must be a minimum of 1-5⁄8 inches. Cvengros brought a simple go/no-go gauge to the shop to check the outside diameter of the Here is an example of a poor 'cage. It is not tucked up against the body of the car, and it looks to us like it might collapse across the driver's legs if the car turns upside down. Here is an example of a poor 'cage. It is not tucked up against the body of the car, and i To check for material thickness, Cvengros uses a sonic tester. The minimum thickness for chromoly is 0.083 on the main 'cage and 0.058, 0.049, or 0.065 depending on where the bar is in the car. All mild steel must be a minimum of 0.118 inch thick. To check for material thickness, Cvengros uses a sonic tester. The minimum thickness for c While we were looking for a good chassis, we found some bad ones. Aside from the bungee cord holding the door closed, this car is bad because the welds have holes, splatter, and have been ground down. Also note the door bar has been cut away from the main hoop and rewelded. We passed, thanks. While we were looking for a good chassis, we found some bad ones. Aside from the bungee co Note how this bad 'cage has a rear brace on the passenger side that is nearly vertical. This could cause the main hoop to collapse rearward in a rollover. Note how this bad 'cage has a rear brace on the passenger side that is nearly vertical. Th Rollcages are required to have foam padding wherever the helmet could make contact. Unfortunately, you'd have to ask the seller to cut it off to inspect the welds. Same goes for paint and Bondo on 'cages that have been smoothed. The NHRA tech will want to see what's under there. Rollcages are required to have foam padding wherever the helmet could make contact. Unfort This car was advertised as race-ready, complete with sheetmetal interior . . . and no rollcage. This car was advertised as race-ready, complete with sheetmetal interior . . . and no roll This car had a great 'cage, paint, and a big-block Chevy. It also had a $50,000 asking price. This car had a great 'cage, paint, and a big-block Chevy. It also had a $50,000 asking pri When the body is open, the rules change. This story refers to door-slammers and full-bodied cars. This Fiat looks like fun, doesn't it? When the body is open, the rules change. This story refers to door-slammers and full-bodie The Demon is now certified to run as fast as 8.50 in the quarter-mile. If you buy a car that already has a sticker, make sure it is current or only three to five years old. Cars that run 8.50 or faster have a special set of SFI rules that change frequently. It might be wise to make the sale contingent on the car passing a new certification check. The Demon is now certified to run as fast as 8.50 in the quarter-mile. If you buy a car th After the bars are checked for thickness and diameter and the tech is satisfied that the welds are strong and the 'cage is built correctly, he will affix a sticker to the chassis. It will be good for three years from the date code. The upper line is the month and the line on the left is the year. The cost is around $200 depending on the duration of the certification. After the bars are checked for thickness and diameter and the tech is satisfied that the w The car is on its way to James White at Circle City Hot Rods for completion of the front-end fabrication, then it's off to artist Harpoon to finish his vision for the paint. Up next, Hemi fun. End The car is on its way to James White at Circle City Hot Rods for completion of the front-e SOURCES Lincoln Electric 22801 St. Clair Ave Cleveland OH 44117 216-481-8100 www.lincolnelectric.com Circle City Hot Rods 2199 North Batavia Street #R Orange CA 92868 714-279-0400 www.circlecityhotrods.com Wilwood Engineering 4700 Calle Bolero Camarillo CA 93012 805-388-1188 www.wilwood.com Classic Industries 18460 Gothard Street Dept. CP Huntington Beach CA 92648 800-854-1280 www.classicindustries.com Coker Tire 13187 Chestnut Street Chattanooga TN 37402 800-251-6336 www.cokertire.com Miller Electric 1635 W. Spencer Street Appleton WI 54912 920-734-9821 www.millerwelds.com Performance Automatic 8174 Beechcraft Ave. Gaithersburg MD 20879 301-963-8078 www.performanceautomatic.com eBay Motors http://hub.motors.ebay.com/ Andrews Powder Coating 818-700-1030 www.powdercoater.com Speedway Motors 340 Victory Lane Lincoln ME 68528 800-979-0122 www.speedwaymotors.com NHRA Glendora CA 626-914-4761 www.nhra.com Chris Alston's Chassisworks 8661 Younger Creek Drive Sacramento CA 95828 916-388-0288 www.cachassisworks.com By Douglas R. Glad Enjoyed this Post? Subscribe to our RSS Feed, or use your favorite social media to recommend us to friends and colleagues!