Mustang Subframe Connections Dazecar.com

Further down is some A-Eye on Chromaly to strengthen frame https://dazecars.com/dazed/home.html ---------------------------------------------------------------------------------- Reinforcing the frame and overall handling of a 1966 Mustang coupe for road racing can significantly improve its performance. Using chromoly (chromium-molybdenum) steel tubes, particularly the 4130 alloy, is common due to its strength-to-weight ratio and durability. Here are some guidelines on tube sizes, wall thickness, and the choice between round and square tubes: Tube Sizes and Wall Thickness Common Tube Sizes for Reinforcement: Main Frame Reinforcement: Round Tubes: Diameter: 1.5" to 2" Wall Thickness: 0.083" to 0.120" (typical thicknesses are 0.095" and 0.120" for higher stress areas) Square Tubes: Size: 1.5" x 1.5" to 2" x 2" Wall Thickness: 0.083" to 0.120" Roll Cage and Roll Bars: Round Tubes: Diameter: 1.5" to 1.75" (1.75" is very common for roll cages) Wall Thickness: 0.095" to 0.120" Shock Towers and Suspension Mounts: Round Tubes: Diameter: 1" to 1.25" Wall Thickness: 0.065" to 0.095" Square Tubes: Size: 1" x 1" to 1.5" x 1.5" Wall Thickness: 0.065" to 0.095" Choosing Between Round and Square Tubes Round Tubes: Advantages: Better in handling torsional (twisting) loads. More aerodynamic, which can be beneficial in racing applications. Generally more available and easier to find in 4130 alloy. Applications: Roll cages, chassis reinforcements, and areas where torsional rigidity is crucial. Square Tubes: Advantages: Easier to fabricate and attach to flat surfaces. Can provide better resistance to bending in certain applications due to the flat sides. Applications: Subframe connectors, crossmembers, and areas where attachment to flat surfaces is needed. Material Choices 4130 Chromoly: The most commonly used alloy in racing due to its excellent strength-to-weight ratio and weldability. Offers high tensile strength and toughness. Available in various forms, including round and square tubes, making it versatile for different applications. Variations: While 4130 is the standard, sometimes other materials like mild steel (for cost considerations) or other high-strength alloys (for specific performance needs) might be used. When using materials other than 4130, ensure compatibility with the intended application and welding processes. Practical Considerations Weight vs. Strength: Balance the need for strength with the need to keep weight down. Over-reinforcing can add unnecessary weight, affecting performance. Welding: Ensure proper welding techniques for 4130 alloy to maintain strength and avoid brittleness. Design: Design reinforcements to work with the car’s existing structure. Properly placed gussets and triangulation can improve stiffness without excessive weight. Conclusion Reinforcing a 1966 Mustang coupe for road racing with chromoly tubes involves selecting the right sizes and wall thicknesses for specific areas. Round tubes are generally preferred for their torsional strength and aerodynamic advantages, while square tubes are useful for certain applications requiring attachment to flat surfaces. 4130 chromoly is the standard alloy used, but other materials might be considered based on specific needs and budget. Proper design and welding techniques are crucial to ensure the structural integrity and performance of the reinforcements.