If you’ve ever driven a NA or NB Miata hard at a track day, autocross, or just a proper backroad, you already know the feeling:

You’re sitting on the car, not in it.

For taller drivers (especially with a helmet), headroom becomes the limiting factor way before skill does. The good news? The Miata chassis gives you more room to work with than you think, you just have to unlock it.

Here are the most common (and actually effective) ways to lower your stock seat, ranked from easiest to most committed.

Option 1: The Foamectomy (Start Here)

This is the gateway mod. Cheap, simple, surprisingly effective.

A foamectomy is exactly what it sounds like, you remove material from the seat cushion to sit lower in the chassis.

What you’re doing:

• Removing the seat
• Peeling back the upholstery
• Trimming foam from the bottom cushion (and sometimes lower back area)

What you gain:

• ~0.5" to 1.0" of headroom depending on how aggressive you go
• Lower center of gravity
• Better helmet clearance for track use

What you lose:

• Some comfort, especially on long drives
• A bit of OEM “plushness”

Pro tip:

Don’t just hack foam out randomly. Shape it. Think ergonomics. Keep support where your sit bones land, remove where it doesn’t matter.

This is the lowest-risk, highest ROI first step. If you’re not happy after this, then it’s time to step things up.

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Option 2: Bottom-Mounting the Stock Seat

This is where things get interesting, and where we come in.

At R Theory Motorsports, we designed bottom-mount brackets that fit bottom mount race seats. They also let you ditch the tall OEM slider assembly and bolt the seat directly to a lower mounting structure.

Sounds simple… but there’s a catch (because Miata).

The problem:

Most OEM Miata seats have a rear “hump” in the seat pan.

That hump interferes with the rear cross rail on bottom-mount brackets.

The solution:

You’ll need to modify the bracket:

• Cut the rear cross rail
• Reposition it lower or further back
• Weld it back in place to clear the seat pan hump

This is not a bolt-on job. It’s a builder’s solution.

What you gain:

• Significant drop vs stock sliders (often 1.5"+ total vs OEM setup)
• Much more “in the car” driving position
• A more direct, connected feel

What you need to think about:

1. Seat Position (This is big)
Our bottom mount brackets don’t have fore/aft adjustment.

That means:

• You’re choosing a fixed driving position
• It will land roughly between the factory mounting holes

If you’re shorter or taller than average, this matters a lot. Measure twice, weld once.

2. Effort Level
This is not a Saturday morning bolt-on unless you’re comfortable with cutting and welding.

Why go this route?

Because when done right, this setup feels proper. It’s the closest you’ll get to a lowered bucket seating positio, while still running a modified OEM seat.

Option 3: Removing the Rear Floor Humps (Point of No Return)

This is the “I’m serious” option.

From the factory, the Miata has raised rear mounting humps welded into the floor. These elevate the rear of the seat and limit how low you can go.

What this involves:

• Cutting/removing the rear humps from the floor
• Drilling new mounting holes through the flat floor
• Using a bolt + washer + nut setup underneath the car for the rear mounts

What you gain:

• Maximum possible seat drop with a stock seat
• The ability to mount seats significantly lower and flatter
• Real helmet clearance, even for taller drivers

What you lose:

• Factory rear mounting points (they’re gone)
• Reversibility (this is permanent)
• Some resale friendliness (depends on buyer)

What you need to do properly:

• Use large washers or reinforcement plates underneath the floor
• Seal everything properly (rust + water = bad time)
• Be mindful of what’s under the car when drilling (fuel lines, brake lines, etc.)

Bonus Options (Depending on How Far You Want to Go)

If you’re already considering the above, you might also think about:

Aftermarket Fixed-Back Seats

• Designed for bottom mount
• No hump interference
• Much easier to get low

Steering Wheel + Hub Setup

Lowering the seat changes your driving position. Pairing it with:

• A smaller diameter wheel
• A proper hub/spacer combo

…makes everything feel intentional instead of compromised.

Final Thoughts

There’s no single “best” way to lower your Miata seat—just the one that matches how far you’re willing to go.

• Foamectomy → quick win
• Bottom mount with modification → enthusiast sweet spot
• Floor hump removal → full commitment

If you’re chasing that feeling where the car wraps around you instead of sitting underneath you, it’s 100% worth it.