Take any two identical cars that are equipped with the same drivetrain, brakes, and suspension and then set them both up to have the same weight and weight balance. If the only difference between the two cars is the rigidity of the frame, do you think it will make a difference on and off the race track?
Ask that question to any experienced race car builder or vehicle designer and the answer will be a resounding YES. All other factors being equal, the higher the rigidity of the frame, the quicker the car will be around a racetrack and on the street. Is that not reason enough to consider improving the rigidity of your project car’s frame?
A stronger frame helps the car handle better in certain road conditions, and will provide you with more security in the event of a collision, which can happen whether on the road or on the track. The following five tips will help you strengthen the frame of your classic car so that it performs at its best on and off the track.
Check the Frame Welds
Check the welds of the vehicle chassis to make sure they are all clean and secure. Little holes within the welds can cause the metal to shift slightly during use. If the welds are not inspected periodically, those small holes could turn into big holes over time, possibly leading to a catastrophic failure of the frame.
If you notice an area where the welds are degrading, you may need some spot welding done. If you’re comfortable welding and are set up for that, then you can do it yourself. Otherwise, it’s recommended to take it to a mechanic or muffler shop.
Add or Upgrade The Crossmembers
A crossmember is a structural support bar that spans the frame of the vehicle in order to support both the engine and the transmission. For your car’s suspension to function at peak performance, the frame and body panels must remain in alignment. The stronger the chassis is, the better the car will handle because the suspension can properly do its job. The frame must be able to withstand the loads and torque applied to it and resist any twisting. To ensure the structural integrity of your frame and body, a crossmember is used.
Just as frame design has evolved over the years, so has the design of crossmembers. G Force Performance Products has taken the original crossmember design and made it lighter weight without compromising on strength and durability.
The next generation crossmember has been independently tested and engineered for optimal fitment to your car while maintaining or even exceeding the strength and durability of legacy crossmember designs.
Adding a Custom Roll Cage
A roll cage offers a sophisticated array of steel bars that tie in many points of the interior cabin in order to make the chassis as rigid as possible. Adding a roll cage to your car is a proven method of strengthening the chassis and thus increasing performance and handling. Going the route of a roll cage is generally going to involve custom welding which is not ideal for an everyday car. But for the muscle car enthusiast looking for that edge on the track, this could be your ticket.
Use a Steering Brace (aka Wonderbar)
Steering braces are not compatible with all classic cars, but they can increase structural strength to the ones they do work for. The steering brace, also known as a Wonderbar, performs two functions; First, it ties the left and right sides of the frame together under the front of the car, improving the overall performance and handling of the car during cornering. Second, the steering brace strengthens the chassis and takes stress off of the steering mount. It is common in 3rd generation F-Body Mustang’s for fatigue and stress cracks to form around the steering gearbox mounting location. That’s why a steering brace is a great option for F-body Mustang owners.
Preventing Rust Buildup
Allowing rust to build-up will eventually harm the integrity of your car’s frame. While you can’t avoid moisture, you can try to keep your car out of the elements by parking in a garage or if outside, at least keeping it covered with a car cover. Proper care and preventative maintenance will keep your car safe and strong for a long time to come.
In addition to the above 5 tips, don’t forget to take the engine compartment into consideration. The engine compartment is a weak point commonly overlooked on classic cars such as the Ford Mustang. With the Mustangs, there is no frame tying the front and rear together; just the unibody style frame. To stiffen the engine compartment a common aftermarket addition is a tubular shock tower brace, combined with a tubular brace between the shock towers and the firewall. Lowering the center of gravity and stiffening the suspension helps mitigate body roll. On classic Ford Mustangs, moving the location of the upper front control arms downward by about an inch improves the geometry of the front wheels, thus improving handling and adjusting understeer and oversteer. Oversized front and rear sway bars also help with the structural integrity and the overall performance of your car.