How to Fit Kirkey Alloy Racing Seats: A Complete Fabrication & Installation Guide
Kirkey Racing Seats are highly respected in the motorsport world for their lightweight, one-piece aluminum construction, making them a go-to choice for drag racing, dirt oval racing, and circuit racing. Unlike conventional road car seats or even FIA-homologated bucket seats, Kirkey seats are not designed to simply bolt onto factory seat rails. Instead, they require custom fabrication to mount securely to your vehicle’s chassis or roll cage.
If you’re considering a Kirkey seat for your build—whether it’s a dragster, track day car, or historic race car—you’ll need to plan and execute a custom mounting solution that ensures both safety and rigidity. These seats lack pre-drilled mounting holes that match standard brackets, meaning that a tailored installation is necessary for optimal driver positioning and compliance with motorsport safety standards.
In this guide, we’ll break down everything you need to know about installing a Kirkey aluminum seat. We’ll explore why standard seat brackets won’t work, what materials and tools you’ll need for fabrication, and how to ensure your installation meets safety regulations such as those set by Motorsport UK (MSA) and the FIA. Whether you’re fitting a seat into a lightweight track car, a historic racer, or a drag vehicle, this guide will give you the essential steps and expert insights needed to install your Kirkey seat correctly and securely.
Overview of Our Kirkey Racing Seat Range
Kirkey produces a wide range of aluminum racing seats to suit different motorsport disciplines and driver preferences. Our range covers everything from vintage-style low-back seats to modern containment seats with head support. Here’s a quick overview of the main Kirkey seat series and their typical applications:
- Kirkey 38 Series – Standard Layback Seat: A versatile 10°–20° layback aluminum seat designed for stock cars and short-track racing.
- Kirkey 55 Series – Pro Street Drag Seat: A popular drag racing seat, with a more upright seating position ideal for dragsters and high-powered door-slammers.
- Kirkey 55V Series – Vintage Class Bucket Seat: A special low-back vintage-style seat designed for historic racing and classic cars.
- Kirkey 58LW & 56LW Series – Lightweight Layback Seats: These are ultralight versions of the layback seat, available in 10° (56LW) or 20° (58LW) layback angles.
- Kirkey 65 Series – Adjustable Layback Road Race Seat: An aluminum road racing seat kit that comes with padding and cover. It’s designed for kit cars, club racers, and entry-level road racing.
- Kirkey 70 & 71 Series – Road Race Containment Seats: These are high-support seats with integrated head restraints (“halo” seats) for greater lateral head protection, used in circuit racing and high-speed track events. These seats have a 20° layback (typically) and large shoulder wings.
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From £300.00 Excl. VAT Select options This product has multiple variants. The options may be chosen on the product page
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From £250.00 Excl. VAT Select options This product has multiple variants. The options may be chosen on the product page
Kirkey’s catalog is extensive (32, 47, 73, 80, 81, 83, 85 series, etc.), but the ones above are the primary models we offer for adult motorsport use. Kirkey even produces child racing seats (Series 16, etc.) for youth racers, which also require custom mounts but are scaled down. No matter the model, all Kirkey seats share the need for custom installation – none are a simple “bolt-in” with generic brackets. Next, we’ll explain why that is and what you need to do to fit these seats properly.
Why Do Kirkey Seats Need Custom Fabrication (No Off-the-Shelf Brackets)?
Kirkey aluminum seats differ from typical aftermarket seats in their mounting approach. A conventional FIA-approved racing seat or OEM seat might use standard bolt patterns or slider rails that attach to manufacturer-specific or universal brackets. In contrast, Kirkey seats are essentially a raw aluminum shell optimized for strength-to-weight, leaving the mounting method up to the installer’s fabrication. Here’s why custom fitting is necessary:
- No Integrated Base or Slider Rails: Kirkey seats come without sliding tracks or fixed base mounts. This is intentional – in serious motorsport, sliders are seen as potential weak points, and Kirkey expects the seat to be hard-mounted for strength. The company explicitly does not recommend using stock sliders or adjusters when installing their seats. In fact, Kirkey provides optional bracket kits but assumes the installer will weld or bolt those to the car’s frame. The absence of a standardized base means you can’t just grab a Sparco or Recaro bracket off the shelf and expect it to line up.
- Universal Fit to Chassis, Not to OEM Mounting Points: Each racing car or project has a unique interior and roll cage geometry. Kirkey seats are often used in tube-frame chassis, drag cars, or heavily modified vehicles where the original seat mounts are gone or altered. These seats are made to be mounted directly to the chassis or cage, positioned exactly where the builder needs them. The manufacturer’s instructions advise using at least four 5/16” (8 mm) bolts through the bottom of the seat into the frame or roll cage, plus two bolts through the seat back into a roll cage bar. This essentially ties the seat into the vehicle’s structure at multiple points. There is no provision for bolting into flimsy factory floor sheet metal or using pre-fab “adapter” plates – doing so would be unsafe and is strictly warned against. Instead, you’re expected to reinforce or create hard mounting points.
- Customisation for Driver Positioning: Because Kirkey seats come in various angles and sizes, the ideal seating position can be very individual. A one-size-fits-all bracket would likely compromise the driver’s comfort or safety. By custom fabricating mounts, you ensure the seat’s angle, height, and distance to pedals/steering are perfect for the driver.
- Safety Standards and Load Distribution: Motorsport governing bodies have specific requirements on how seats must be attached. The UK’s Motorsport UK (MSA) regulations require a minimum of four mounting points with at least 8mm diameter high-tensile bolts, each backed by load-spreading plates of at least 40 cm² area (and 3mm thick steel or 5mm aluminum) on the chassis. This is to prevent the bolts from tearing through the floor in a crash. Achieving this usually means drilling new holes and adding reinforcement – again, a custom job.
Planning Your Kirkey Alloy Seat Installation: Positioning, Measurements & Preparation
Installing a Kirkey seat isn’t as simple as bolting it in—it requires careful planning and custom fabrication. Follow these key steps to ensure a safe and secure installation.
1. Check Motorsport Regulations & Requirements
- Review motorsport rules for your racing class or event.
- Some series require a seat back brace if the seat isn’t FIA-approved.
- Motorsport UK, FIA, and NHRA specify seat mounting hardware (e.g., 8mm/5/16” bolts, reinforced mounting plates).
- Always check with your sanctioning body for compliance.
2. Choose the Right Seat Model & Size
- Select the correct Kirkey seat model for your vehicle and racing discipline.
- Ensure a proper fit—Kirkey seats come in different widths (e.g., 15”, 16”, 17”) to suit different body sizes.
- Consider seat layback angles (e.g., 10°, 20°) to match your car type and driver preference.
- We can assist in choosing the right seat for your build.
3. Mock-Up the Seating Position
- Remove the existing seat and clear the mounting area.
- Place the Kirkey seat in position using blocks or stands to simulate final placement.
- Have the driver sit in the seat to check steering, pedal reach, and visibility.
- Ensure shoulder harness slots align with the driver’s shoulders.
4. Mark Mounting Points & Check Clearance
- Identify solid mounting points on the chassis and roll cage:
- Floor Pan / Lower Chassis Rails – Look for reinforced sections or install a transverse mounting rail.
- Roll Cage Bars – Secure the seat back to an existing or fabricated seat support bar.
- Ensure the seat fits without obstructing the doors, roll cage, or harness routing.
5. Gather Tools, Materials & Brackets
- Tools: Angle grinder, power drill, measuring tape, clamps, and welding equipment if needed.
- Materials: Steel flat bar, angle iron, or tubing for fabrication.
- Hardware: High-grade bolts (8.8 or higher), nylock nuts, and large backing washers.
- Optional Brackets: Kirkey offers prefabricated seat mounts for easier installation.
6. Double-Check Measurements Before Cutting
- Mark out the mounting positions clearly before drilling or welding.
- Use a plumb line or laser level to align the seat correctly.
- Ensure the seat sits straight and is positioned securely for optimal driver safety.
Step-by-Step Guide to Fabricating & Mounting a Kirkey Seat
Mounting a Kirkey seat properly is critical for safety and performance. The goal is to attach it to a solid structure (frame or cage) with robust hardware and reinforce the seat back to prevent movement under load. Follow these steps:
Step 1: Install or Fabricate Seat Base Mounts
The seat base needs at least four secure attachment points. Here are some options:
- Welded Crossmembers – Weld two steel tubes across the floor (one at the front, one at the rear of the seat base) and bolt the seat to them. Use 1.5” x 0.125” wall steel tubing for strength.
- Fabricated Brackets – Use L-shaped steel angle or flat bar bolted to the floor with large backing plates. Bolt the seat to these brackets for a secure mount.
- Kirkey Side Mount Kit – If using Kirkey’s 99214 side-mount brackets, bolt them to the seat first, then weld or bolt their base to the floor or chassis. Never bolt directly to sheet metal—always reinforce.
- Align & Drill – Once the seat position is set, mark and drill holes for 5/16” (8mm) or 3/8” (10mm) bolts. Deburr holes and apply paint to prevent corrosion.
Step 2: Secure the Seat Base
- Position the seat and insert at least four bolts through the base.
- Use large-diameter washers or spreader plates to distribute the load and prevent pull-through.
- Tighten bolts gradually but leave some adjustment room until the seat back brace is installed.
- Check stability – If the seat base flexes, reinforce it before proceeding.
Step 3: Fabricate the Seat Back Brace
A properly braced seat back prevents flexing in an impact.
Mounting Options:
Roll Cage Bar Method – If a horizontal roll cage bar is behind the seat, bolt the seat back to it using Kirkey’s rear mount bracket (PN 99212) or a fabricated L-bracket. Use two bolts spaced vertically for strength.
Floor/Bulkhead Brace – If no roll cage, fabricate a diagonal steel tube brace from the seat back to the floor, rear bulkhead, or a reinforced mounting point.
Adjustable Seat Back Braces – Use telescoping brackets or Heim joint rod ends to allow minor adjustments while keeping the brace rigid when locked in place.
Important: Always attach the brace below the shoulder belt openings for maximum strength.
Step 4: Final Alignment & Tightening
- Final Position Check – Have the driver sit in the seat and verify comfort, visibility, and reach.
- Torque All Bolts – Secure everything to proper torque specs (8mm bolts ~20-25 Nm, 10mm bolts ~40 Nm). Use nylock nuts or thread locker to prevent loosening.
- Inspect Welds & Fabrication – Ensure welds are solid and smooth out any sharp edges.
- Reinstall Interior & Harnesses – If applicable, trim carpets or panels for a clean fit.
- Final Safety Check – Shake the seat forcefully. The car should move on its suspension, not the seat in its mounts.
A well-mounted Kirkey seat improves safety, durability, and driver feedback. Now, you’re ready to hit the track with confidence!
Ensuring Compliance with Motorsport Safety Standards
Mounting a seat isn’t just about fabrication—it’s a critical safety task. Here’s how to ensure your Kirkey seat meets or exceeds motorsport standards.
Seat Homologation & Expiry
FIA seats expire every 5 years, but aluminum seats like Kirkey don’t have an expiry date.
Some racing series only allow FIA-certified seats, so check regulations before competing.
Many grassroots series (Autocross, hill climbs, drag racing, etc.) allow Kirkey seats if mounted securely.
NASA & SCCA require a seat-back support bar for non-FIA seats. NHRA allows aluminum seats but follows SFI specifications for other gear.
Bolts & Backing Plates (MSA/FIA Compliance)
- Motorsport UK & FIA require at least four M8 (8mm) grade 8.8 bolts with 40 cm² steel backing plates for secure mounting.
- Most Kirkey seats aren’t FIA-homologated, so many racing series require a seat-back brace for added support.
- During scrutineering, officials will check mounting security and seat condition—replace damaged seats to avoid disqualification.
Harness Integration: Mounting for Maximum Safety
- Shoulder straps must be mounted within 4 inches (10 cm) of shoulder height and should be close to horizontal when routed through the seat.
- Submarine belts should pass through the seat bottom (using factory slots or a reinforced grommet) and be mounted securely to the floor with backing plates.
- Lap belts should be positioned at a 45° backward angle and spaced properly to fit over the pelvis—follow FIA & harness manufacturer guidelines.
Padding & Headrests: Essential for Protection
- If your Kirkey seat lacks a headrest, most racing rules require a padded head support behind the driver.
- Roll cage padding or bolt-on headrest pads can be added to prevent whiplash in a rear impact.
- If using a containment seat with head supports, ensure proper fit with your helmet and HANS device. Add soft padding if necessary.
Fire Safety Considerations
- Aluminum seats transfer heat faster than padded stock seats—install a heat shield if exhaust or other hot components are nearby.
- While not a direct requirement, heat protection improves both safety and comfort, especially in endurance racing.
Professional Inspection: Get It Right
- If unsure about your installation, have a fabricator or scrutineer inspect your work.
- Kirkey’s own instructions advise having a professional handle fabrication if you’re not experienced.
- Your safety depends on this seat in a crash—don’t take risks, and when in doubt, ask an expert.
Conclusion: Expert Support from Us and Final Thoughts
Installing a Kirkey alloy racing seat requires precision and attention to detail, but the result is a secure, competition-ready setup. By selecting the right seat, planning the installation properly, and using the correct hardware, you’ll create a safe and comfortable connection to your car.
At GSM Performance, we supply the full range of Kirkey racing seats to customers across the UK and beyond. With years of experience in motorsport seating, we’re here to help you choose the right seat, brackets, and installation solutions. If needed, we can even connect you with professional fabrication services.
Key Takeaways for a Safe & Compliant Installation
✔ Mount to a solid structure – never rely on thin sheet metal. Reinforce every attachment point.
✔ Use proper-grade hardware – at least four bolts on the base + two on the back, with large backing plates.
✔ Seat-back braces are mandatory for aluminum seats to ensure safety.
✔ Take your time with alignment and fabrication – small mistakes can cause big problems later. Measure twice, drill once!
✔ Check your motorsport rulebook to comply with regulations on belt angles, headrests, and mounting methods.
✔ Seek expert advice when needed – whether from fellow racers or our team at GSM Performance.