Motorsports Welding and Racing Repair Guide

Tips for race car repair and fabrication

Jump to:

• How to choose the best welder for motorsports fabrication
• Engine/cooling/exhaust repairs
• Chassis fabrication
• Welding front suspension
• Welding rear suspension
• Finish fab projects
• Pit crew support equipment projects
• Safety equipment for motorsports welding 

No matter what or where you race — whether it’s cars, trucks or modifieds, on road courses, dirt tracks, dragstrips or off-road terrain — Miller has the equipment to help you build, modify and repair motorsport vehicles. But how do you choose the welding product best suited to your needs? This comprehensive guide will help you navigate the options and select the ideal welding products for your specific needs. 

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Purchasing welding equipment for motorsports

There are several key factors to think about when choosing welding equipment for motorsports applications.

• Material type: Think about what material you will weld most frequently, whether it’s steel, 4130 alloy steel, aluminum, stainless steel or titanium. These materials are common across all forms of motorsports, with the main variable usually being material thickness. 

• Material thickness: The maximum and minimum material thicknesses you will weld determine what amperage capacity you need in your machine.

• Input power: Consider the available input power in your garage, shop or manufacturing facility. Is it 120-volt or 240-volt, single-phase or three-phase? Will you need a machine that can handle all of the above? 

• Skill level: The welding skill level of the operator helps determine the complexity or feature set to look for in a machine. Some welding machines are designed with push-button control and easy-set features that make setup and adjustment simple. For example, the Millermatic® 211 PRO offers advanced capabilities such as Auto-Set™ technology, which allows you to select the perfect parameters with the click of a button, making it an ideal choice for professional auto shop applications. 

• Preferred process: Determine which welding process you will use the most — MIG or TIG. You can purchase a MIG welder or a TIG welder, or you may want to consider a multiprocess welder to maximize your capabilities with one machine. 

• Output capacity: Are your welding applications considered light production or manufacturing? The demands of each type of work are different and will determine the duty cycle requirements you need in a welder. For beginners, light production welding is a great starting point, while professionals might require more robust machines for manufacturing applications.

Tackling motorsports welding projects

There are common welding tips and tricks that can help you with each part of your build, modification or repair project. We’ve covered some of the most common below.

Engine, cooling and exhaust

To handle the thick metal of cylinder heads and the thin metal of radiators — and everything in between — you need a versatile welder with a wide range of output capabilities and arc adjustability to perfectly match every job. The Dynasty® series machines are an excellent choice for this work. 

Common welding projects and guidelines: 

• Intake manifolds: Typical materials for these projects are aluminum 3003, 6061 or A356 castings. The recommended welding process is AC TIG with 4043 and 4943 filler metals.

• Cylinder head repair: Typical materials for these projects are billet and A356 cast aluminum. The recommended welding process is AC TIG with 4043 or 4943 filler metals. 

• Headers and exhaust: Common materials for these projects are mild steel, 304 or 321 stainless steel and Inconel. The recommended welding process is DC TIG with recommended filler metals ER70S-2 (mild steel), 308 or 347 (stainless steel), 309 (stainless to mild steel) or 625 (Inconel). 

• Aluminum radiators, heat exchangers and tanks: Materials for these projects are often 3003, 5052 and 6061 (for fittings, bungs and necks). The recommended welding process is AC TIG with 4043 and 4943 filler metals. 

• Oil pans: Typical materials for these projects are mild steel and 3003 aluminum with 6061 components. The recommended welding process is DC TIG for steel and AC TIG for aluminum. Recommended filler metals are ER70S-2 or ER80S-D2 (steel) and 4043 or 4943 for aluminum.  

Chassis fabrication

When many dozens of welds all work together and help the chassis respond to the stresses of racing like it’s made of a single piece of metal — that’s when you know you used the right welder for the job. The inverter-based Millermatic^® 211 and Multimatic^® 215 welders are preferred for this.

Common welding projects and tips: 

• Body: Mild steel is the material typically used for body projects. The recommended welding process is MIG or MIG spot with .024-inch ER70S-6 filler metal. 

• Full chassis and roll cage: Typical materials for these projects are mild steel or 4130 chromoly. MIG or TIG is often recommended, and the choice may depend on sanctioning body rules. Commonly used filler metals are .030-inch to .035-inch ER70S-6 for mild steel with MIG, ER70S-2 for mild steel with TIG, and ER80S-D2 for mild steel/4130 with TIG. 

Front suspension

The front suspension of a motorsport vehicle plays a critical role in handling and stability. Maintaining proper suspension geometry under challenging conditions is a team effort — and strongly welded suspension components are key players. The Millermatic, Multimatic and Dynasty machines offer the precision and durability needed for these critical welds.

Common welding projects and tips:

• Upper control arms: Typical materials for these projects are mild steel and 4130 chromoly. The recommended welding process is DC TIG, with filler metals ER70S-2 for mild steel and ER80S-D2 for 4130.

• Lower control arms: Mild steel and 4130 chromoly are the materials most often used in these projects. Recommended welding processes are MIG or DC TIG. Recommended MIG filler metal is .030 to .035-inch ER70S-6 for mild steel, and recommended TIG filler metals are ER70S-2 for mild steel and ER80S-D2 for mild steel/4130.

• Spindles: Typical materials for these projects are mild steel, 4130 tubular fabricated and 4140 chromoly solid. Recommended welding process is MIG or DC TIG. Recommended MIG filler metal is .030 to .035-inch ER70S-6 for mild steel and recommended TIG filler metals are ER70S-2 for mild steel and ER80S-D2 for 4130 and 4140.  

Rear suspension

The rear suspension is vital for traction and stability, especially in high-performance motorsport applications, where longevity and reliability are essential. Properly welded rear axle housings, lower control arms, trailing arms, track bars and wheelie bars have many different jobs but one common goal: maximizing traction and power delivery. 

Common welding projects and tips: 

• Wheelie bars (drag): Typical materials for these projects are 4130 chromoly and grade 9 titanium. The recommended welding process is DC TIG, with recommended filler metals ER80S-D2 for 4130 and ERTI-9 for titanium. 

• Lower control arms, trailing arms and track bars: Material for these projects is typically mild steel, with MIG or DC TIG as the recommended welding process. Recommended MIG filler metal is .030 to .035-inch ER70S-6, and recommended TIG filler metal is ER70S-2 or ER80S-D2.

• Rear axle housing: Mild steel is most commonly used, with MIG or DC TIG as the recommended welding process. Recommended MIG filler metal is .035-inch ER70S-6, and recommended TIG filler metal is ER70S-2 or ER80S-D2.  

Finish fab

Finish fabrication involves the final touches that enhance not only the vehicle's performance but also its aesthetics. Using the right welding equipment ensures that these final components are both functional and visually appealing. Given the wide variety of metal types, thickness and amperage needs in finish fabrication, it’s important to have a versatile welder that never compromises on arc quality. The Multimatic 220 AC/DC is a perfect fit for these welding jobs.

Common welding projects and tips: 

• Duct work: Duct work often requires 3003 aluminum, and the recommended welding process is AC TIG with 4043 or 1100 filler metals. 

• Seat/safety: Typical material for these projects is 5052 aluminum, and the recommended welding process is AC TIG with 5356 filler metal. 

• Bumpers, rub rails and nerf bars: Common materials for these projects are mild steel, 4130 chromoly and 304 stainless steel. Recommended welding processes are MIG and DC TIG. Recommended MIG filler metal is .030-inch ER70S-6 for mild steel, and recommended TIG filler metal is ER80S-D2 for 4130 and ER308L for 304 stainless steel.  

Support equipment

Only one driver finishes first. A good support team — and good support equipment — can make all the difference in getting the win. Common support equipment projects include cooldown units, crash and generator carts, command and pit boxes, and tire and gas carts. 

Engine-driven welders and Multimatic/multiprocess welders combine to make a complete support solution.

Common welding projects and tips:

• Typical materials: mild steel frames and 3003, 5052 or 6061 aluminum for subassemblies

• Recommended welding process: MIG or AC TIG

• MIG filler metal: .030-inch to .035-inch ER70S-6 for mild steel

• TIG filler metal: 4043, 4943 or 5356 for aluminum 

Safety equipment 

Just as important as choosing the right welder for the job is choosing proper safety gear and welding accessories to meet all your needs. Safety should be a top priority in every shop and garage.  

Your list of proper safety gear for motorsports welding includes:

• Welding helmet: Helmets come in a variety of styles, from basic to advanced. Larger viewing areas can help you see the weld better, and auto-darkening helmets let you keep your hood down and finish more welds.

• Head and face protection: Weld masks are a great option for welding in confined areas where traditional welding helmets are a tight fit, such as inside roll cages or under vehicles.

• Safety glasses: Look for glasses that provide optimal eye coverage and increased comfort for all-day wear.

• Respirator: Respiratory protection is key during welding and the intense grinding that is required in custom fabrication.

• Jacket: A lightweight weld jacket can provide superior protection without compromising comfort.

• Gloves: Welding gloves are available in many styles and options, including metalworker gloves designed for metal fabrication and mechanic work, multi-task gloves perfect for MIG and TIG welding, and TIG gloves that deliver protection in a thinner style so it’s easier to feel and manipulate TIG filler metal. 

Solutions for racing and motorsports welding 

Don’t hit the starting line until you know your racing build, modification or repair is ready. Choose welding equipment and accessories that will help you optimize your results — and your performance.