Mirco RTX-7 3D STI Edition FIA Motorsport Seat

From £430.80 Incl. VATFrom £359.00 Excl. VAT

Mirco RTX-7 3D STI Edition FIA Motorsport Seat by Mirco Racing Seats. Approval: FIA 8855-1999. Brand: Mirco Racing Seats. Coloured Shell: Black, Blue.

Coloured Shell

Optional Extras

Personal Name Embroidery

Upgrades Not Required

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Size/Fitting guide

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The RTX-7 3D STI Edition is a specific pre-built trim based on the RTX-7 shell, finished with Subaru Impreza blue cushions on the back, base and leg pads, pink STI stitching, and no embroidery on the headrest. Part code MIRCO-RTX-7-3D-STI-Edition. This is not a custom order: the trim is fixed and ships as shown.

The shell is the RTX-7 design, FIA 8855-1999 approved and weighing 9kg. It is lighter than the RS7 at 11kg while being heavier than the GT at 8.2kg. The 3D SpaceTech mesh fabric is breathable, which makes it more comfortable in warm conditions than velour or vinyl. Driver limits are 95kg and 190cm, covering taller and heavier drivers without the restrictions of the GT or RS1. Five harness slots accept five or six-point harnesses. HANS-compatible, side mount. Shell colour options include black and blue.

The practical question for most buyers is whether the STI finish works for the car. It is a strong look that suits Subaru Impreza and WRX STI builds well, and also works in any black interior that can carry coloured stitching. Personal name embroidery can be added via the dropdown at checkout.

For an RTX-7 without the themed trim, the vinyl no-embroidery version is available at £449 and covers more shell colour options. If you want the RS7’s extreme lateral bolstering on that platform, that is a separate listing. Price is for a single seat.

Additional information

Weight	7.9 kg
Dimensions	80 × 60 × 120 cm
Approval	FIA 8855-1999
Brand	Mirco Racing Seats
Coloured Shell	Black, Blue, Grey, Orange, Red, White, Yellow
Construction	Fibreglass seats
Driver Height	Over 6ft, Under 6ft
Driver Waist Size	32" – 36" waist
Harness compatibility	4 point compatible, 6 point compatible
Optional Extras	Personal Name Embroidery, Upgrades Not Required
Product Colour	Black and Blue
Trim Material	3D SpaceTech
Fixing Type	Side mount
HANS Compatibility	HANS Friendly
Mechanism Type	Fixed Back Seats
Stitching Colour	Pink Stitching

Mirco seat size guide

Mirco make one size of each shell and size the driver by weight and height rather than by waist. The trick is picking the shell built for your build.

How Mirco size their seats

Mirco publish a maximum driver weight and height for each FIA model rather than a waist. The GT is the slim one: up to 85 kg and about 170 to 185 cm. The RS2 goes to 95 kg and 190 cm, the RTS-2 to 100 kg and 190 cm, and the Classic to 100 kg and 185 cm. The RTX-7 is the widest shell in the range at 600 mm across the shoulders.

Across the whole range the shoulder width runs from 490 mm on the Flyer to 600 mm on the GTM and RTX-7. Our waist bands put nearly every Mirco at 32 to 36 inch, with the RTS, RTS 2 and XL also listed at 36 to 40. If you are at the top of a band, take the wider shell.

The RTX-7 in numbersShoulder width 600 mm, hip bolsters 490 mm, lap belt slots 385 mm apart, base 420 x 615 mm, backrest 645 mm, overall height 920 mm, side mount holes 290 mm apart, 9 to 10 kg depending on trim.

Which Mirco fits you

Model	Waist band	Driver height	Shell	Approval
FIA 8855-1999
GT (all trims)	32 to 36	Under 6 ft on most trims	Fibreglass	FIA 8855-1999
RS1	32 to 36	All heights	Fibreglass	FIA 8855-1999
RS2	32 to 36	All heights	Fibreglass	FIA 8855-1999
RS7	32 to 36	All heights	Fibreglass	FIA 8855-1999
RTS and RTS 2 (all trims)	32 to 36 or 36 to 40	Under and over 6 ft	Fibreglass	FIA 8855-1999
RTX 7 (all trims)	32 to 36	Under and over 6 ft	Fibreglass	FIA 8855-1999
Classic FIA (Diamond, Houndstooth)	32 to 36	All heights	Fibreglass	FIA 8855-1999
Road, track and sim (not FIA)
GTS, GTM, GT Day, LS, ST, SX5, SX6, WRC	32 to 36	All heights (GRP GTS, ST and WRC under 6 ft)	Fibreglass or carbon	Road and track, sim
MX5 (all trims)	32 to 36	Under 6 ft on most trims	Fibreglass or carbon	Road and track, sim
XL and XL Diamond	32 to 36 or 36 to 40	All heights	Fibreglass or carbon	Road and track, sim
S2000, S3000	32 to 36	All heights	Fibreglass or carbon	Road and track
Flyer, S, S Retro, CLS2, FX1	32 to 36	Under 6 ft (CLS2 and FX1 all)	Fibreglass	Road and track

Mirco driver limits

Mirco’s own figures for the FIA shells. They describe them as approximate, so treat a driver right on a limit as a candidate for the next shell up.

Model	Max driver weight	Max driver height	Seat weight
GT	85 kg	185 cm	8.2 kg
RS2	95 kg	190 cm	10.0 kg
RTS-2	100 kg	190 cm	8.8 kg
Classic	100 kg	185 cm	8.7 kg
RTX-7	Widest shell, 600 mm shoulders	Under and over 6 ft	9 to 10 kg

All the FIA shells are side mount with the holes 290 mm apart, five harness slots and HANS friendly.

Measure yourself first

Four numbers decide whether a seat fits. Take them in the clothes you drive in, and write them down before you compare models.

AWaistAround your natural waist, not your trouser size. Trouser sizes usually run an inch or two under the real figure, and the waist bands on our product pages use the real one.

BSeated hip widthSit on a hard chair with your feet flat and measure straight across the widest point of your hips with a rule or a straight edge, not a tape that follows the curve. This is the number that decides whether a fixed shell is tight.

CShouldersStraight across the back at the widest point. Fixed back seats hold you here, so a shell that is narrow at the shoulders is uncomfortable long before it is unsafe.

DHeight and torsoYour height, and if you are over 6 ft whether that is mostly leg or mostly body. A long body needs a taller shell with the head support set higher.

Before you order

Check the car, not only the driver. Transmission tunnels, door cards and B pillars are what stop a wide shell going in. Our seat mounting and fixing points guide covers what to measure.
Side mount and base mount shells are not interchangeable. Which one you need depends on the car and the subframe, so pick the brackets at the same time as the seat.
If you run a HANS or plan to, filter on HANS friendly. The shoulder openings are cut to clear the collar.
FIA seats carry an expiry date on the homologation label. Check what your championship accepts and how long the seat has left, particularly on discounted older stock.

Send us your measurementsWaist, seated hip width, height and the car. We have fitted a lot of Mirco seats and will tell you honestly if the one you have picked is going to be tight. Call 0115 989 3488 or email Sales@GSMPerformance.co.uk.

Waist bands and heights are our product data, checked 6 September 2026. Driver limits, weights and the RTX-7 dimensions are from Mirco’s product pages, read the same day.

Have you written anything about this exact product?
Yes, we have covered this exact product: One pair only: the Mirco RTX-7 Blue Stitch Limited Edition has landed in the showroom, and A Mirco RTX-7 in a sim rig: fitting an FIA bucket seat to an aluminium profile cockpit. That is first-hand coverage from our own builds and showroom, not brochure copy.

Will I fit in this seat?
The maker sizes this seat for drivers over 6ft and under 6ft in height with a 32in to 36in waist. Those are the paper numbers; how a seat actually feels to sit in and climb out of is a different question, and our showroom team sit in these seats every day, so call us with your height and waist and we will give you the honest answer.

Is it FIA approved, and for how long?
Yes, it carries FIA 8855-1999 homologation. Every FIA seat has a not-valid-after year printed on its homologation label, and that label date is what a scrutineer checks, so look at the label on the seat you receive and check it against your championship regulations. Buying new means you get the freshest label the maker currently produces.

What do I need to fit it to my car?
This is a side-mount seat: it hangs between side brackets, the motorsport-style stack with fine height and angle control. You will need the car-specific frame, and a sliding runner if you want fore-and-aft adjustment. Our guide on base mount versus side mount walks through the whole stack, and tell us your car and we will quote the full kit.

Does it work with harnesses and a HANS device?
The shell takes 4 point compatible and 6 point compatible. If you are planning the full seat, harness, and HANS setup, tell us the car and we will spec it end to end.

How do I know it will feel right, not just fit on paper?
Fair question, because makers publish widths and weights, never feel, and two seats with identical numbers can feel nothing alike in the car. We keep the ranges on display in the Nottingham showroom, you are welcome to come and sit in them, and if you cannot get to us, call and describe your build, as the team sit in these seats every day. Our head support measurements guide shows the kind of real-world data we collect.

Availability

Mirco seats are custom-made to order

The reason is the choice: over 250 colours and thousands of trim combinations, so each seat is built to the specification you pick rather than taken off a shelf.

That includes the fabric, the colours and the stitching. Lead times vary with the specification, so ask us when you order.

Built to your specification

A seat made to your own trim choice cannot be cancelled once production has started, and our special order terms apply.

Not sure what works together? Ring us. We see these seats in the showroom every day and can tell you how a combination actually looks.

In-store displays:

We have a premium range of over 125 seats from brands including: Bimarco, Cobra, Corbeau, Sparco, OMP, Recaro, GP-Race, and Bride to name just a few brands we work with.

Alongside this, we also stock and display HANS devices, harnesses, race-wear, race-suits, FIA helmets and various other safety equipment. If you are looking to visit us to see and try any particular seat or product, please contact us in advance and we’ll be happy to help.

In-Store appointments:

Due to the specialist nature of our services, we do ask that you please contact us in advance to book an appointment. We have multiple slots available each day including selected availability at the weekend.

Working by appointment allows us to dedicate our time with you and provide a personal and professional service. We’ll always ensure you leave with the right equipment for your needs.

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Choose Klarna at checkout and pick the plan that suits you. The options and amounts for this product are shown below, and they update when you choose an option above.

Use the purchase power check in the Klarna box for a quick, no-obligation look at what you could be approved for before you order.

How it works at GSM SportSeats4u

1Add the product to your basket and go to checkout as normal.
2Select Klarna as your payment method and choose your plan. Klarna gives you a decision in seconds.
3We dispatch straight away. You pay Klarna on the schedule you chose, and any refund goes back through Klarna.

Your questions, answered by Klarna

Klarna is available to UK residents aged 18 and over. Subject to status. Terms and conditions and late fees apply. Klarna Financial Services UK Limited is authorised and regulated by the Financial Conduct Authority. Full details at klarna.com/uk. Every way you can pay with us is on our payment and finance page, or call 0115 989 3488 and we will talk it through.

Fast delivery lead times:

If you require fast delivery, please contact us in advance of ordering and we’ll happily check stock allocation and availability for you. We carry a large amount of stock at our showroom and across multiple distribution hubs. This allows us to provide immediate dispatch across a huge number of brands from Corbeau and Cobra through to Sparco and OMP. (Does not apply to all items)

Due to the niche market we work in, some products are custom hand made to order, or special order from manufacturers like PCI Racing and Planted Technology. If you want to know how fast a product will be dispatched. Simply drop us a message through our Contact us form.

Addtional lead time notes:

Quick dispatch: Stocked products are dispatched within 24-48 hours with Parcel Force.
Sparco roll cages: We can only deliver these to a registered (LTD) company address.
In-store collection: Please contact us in advance to book an in-store collection appointment.