This mid '70s Nova races in a Street Stock class and was damaged in a hit to the side. Sin
There are a relative few who can race an entire season without banging up their racecar. Those people are either so good they are sailing clear at the front against outmatched competition, or so bad they can't catch up to the action. For the rest of us, wrinkled sheet metal and occasionally twisted frames are just part of the game. After all, if you took the rubbing and bumping out of stock car racing, you would have to start calling it Indycar.
So the question becomes, "When the inevitable happens, what's the easiest and best way to get my car fixed so I can get back out on the track and be competitive once again?" If you race a tube-frame car such as a Late Model, the answer usually is to cut out the damaged section and splice in new tubing. But if you are in a class where part of the chassis is required to remain stock, frame damage can create a much trickier situation. With a stock frame, whether it is the front clip or the center section, cutting away a section of damaged frame and replacing it can be very difficult to do correctly. This is especially true in unibody cars, where the chassis and sheet metal are a single unit.
Once up on the frame table, it is easier to see the damage. A hit to the side has pushed t
One answer is to take your damaged racecar to a traditional body shop just like you would a wrecked street car. Most body shops are equipped with a frame table (also referred to as a frame bender, a chassis stretcher or many other similar versions), which is essentially an extremely sturdy jig on which a chassis can be pulled back into shape. A good body shop will have several different tools available that work with the frame table to pull a damaged frame back into shape. The results aren't perfect (for example, you can flatten out a balled-up piece of notebook paper, but you can never get all the wrinkles out), but in many instances a competent body man can get it close enough to get your wheels back in alignment so you can go racing again.
You may, however, have to do a little calling around. Some shops-mostly large chains-are not willing to work with racecars. Also, because of the rollcage, racecars behave differently on a frame table than a standard over-the-road car. If you are really lucky, you will be able to find a racer who also works in a body shop. This is the case with Dirt Late Model driver Chris Hargett who works at Eddie's Paint and Body (Eddie is Chris's dad). Hargett is one of those racers everybody knows who seems to spend as much time helping others with their racecars as he does working on his own.
You might think that the dent on the left-side framerail would shorten the wheelbase on th
"There is a lot you can do with these machines if you are patient and pay attention to what you are doing," Hargett says. "A lot of times, though, the only way to know if you can stretch a frame back into shape is to put it up on the table and start pulling. But there is really nothing to lose since the worst-case scenario is that you will have to cut the damaged sections off-which is what you would have to do otherwise.
"If you are racing a body-on-frame car, then there is a lot you can do to pull it back into shape. But the unibody cars are really common in the stock classes now, and they can be tougher to work with. That is because they really do not have framerails. There is usually something that looks a little bit like a framerail, but much of the structure is provided by the floor, the firewalls and even the roof. Because it is all connected, a hard hit can push and twist the metal in a lot of different directions."
Hargett says with a unibody car, the damage that can most dependably be fixed is a hit from the side that bends the metal in one direction. What is really difficult to fix, though, is a head-on collision that causes the sheet-metal to crumple like an accordion. "When it is bent in all different directions, I can try to pull it back out," he says, "but they are usually trash."
According to Hargett, the best way to avoid the dreaded "accordion" is by installing an intelligently designed rollcage. The first step is to attach the 'cage to the car in several areas. Four is the absolute minimum. A better idea is to attach the 'cage to at least six points on the car, tying the inside of the driver's compartment together, and include kickers that connect to the front and rear clips in at least two points each. Any bars that connect to the car should never be welded directly to the sheet metal. The sheet metal is too weak and will only tear away from the rollcage in a hard hit. Instead, weld a plate to the sheet metal that's at least four inches square, then weld the tubing to that. Additionally, an excellent addition for unibody cars is to run lateral 'cage bars just above the floor along each side of the car that attach to the 'cage's front and rear down tubes. This provides significant additional strength to the car's frame in the event of a big hit from the front.
Often, if your car has damage to the front or rear clip, you may be forced into a fair amount of disassembly so that you can identify the extent of the damage. One area of concern should be the fuel cell as well as the fuel-cell cage at the rear of the car. If you take a hit to the rear of the car strong enough to tweak the metal casing of the fuel cell, Hargett recommends removing the fuel cell before trying to pull the rear clip back into shape. This is because the hit was hard enough to bend something in the fuel-cell cage and tweak the metal casing of the fuel cell. If you tried to straighten it out, it could damage the cell even more. If, however, the fuel cell is undamaged, it is usually okay to try to straighten the frame with the fuel cell installed.
Taking careful measurements is the only way to know exactly what has moved. And the only w
This is an important tool in frame repair. It grabs onto the pinch welds that are so commo
With the tool locked in place on the damaged portion of the chassis, the car can be locked
After repairing the framerail as good as possible, Hargett and Mullis turn their attention
Hargett found that the forward leaf spring mount had been damaged. Pushing up on the mount
The front cross member provides a lot of rigidity, so in the event of a side hit to the fr