Real Race Seats 70 Litre Poly-Bead Resin Seat Insert Kit

Name: Real Race Seats 70 Litre Poly-Bead Resin Seat Insert Kit
Brand: Real Race Seat Inserts
SKU: REARE-RDK-08-701
Price: 291.28 GBP
Availability: InStock

£349.54 Incl. VAT£291.28 Excl. VAT

Complete DIY kit for moulding a seat insert to your own shape. Micro poly-beads and slow cure resin, cured under vacuum. 70 litre kit.

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Size/Fitting guide

SKU: REARE-RDK-08-701 Categories: Real Race Seat Inserts, Race Seat Insert Kits

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Two drivers in the same car can need very different amounts of insert material. A driver who is lighter or narrower than the car was designed around has more cockpit space to fill. That extra space has to go somewhere. Get the volume wrong and the insert sides do not reach the driver’s hips, or the base sits lower than it should, shifting the steering wheel and pedal positions from where the team set them.

The 70-litre Real Race kit, part REARE-RDK-08-701, is designed for open-cockpit sports cars and single-seater cockpits including Formula 3, Formula Renault, and Ginetta, specifically where a smaller driver needs more material than the standard 50-litre kit provides. Where the 50-litre kit handles an average-sized driver in those cars, the 70-litre kit handles the driver who has more cockpit space to fill. It also covers a broader class of open-cockpit sports car where the interior pan is larger or the cockpit sides are less enclosed than in a pure single-seater.

The approach: place the liner in the cockpit and let the driver settle into it before any resin is introduced. Mix the poly-beads and slow-cure resin with the included black pigment and add the mix to the liner. The driver holds the correct seating position while a vacuum pump draws through the attached valve to lock the liner to that profile during curing. The slow cure rate gives time to confirm the seating position before the resin is committed, which is particularly useful when fitting a driver who is not the standard size for the car. The vacuum pump and hose are not in the kit and are sold separately. The finished insert is covered with the included fire-retardant anti-bacterial brushed nylon fabric, or the Real Race spacer fabric covering as a breathable alternative.

For a standard-sized driver in Formula Renault, Ginetta, or SF Chassis, the 50-litre kit is the starting point. For the largest cockpits in the range, the 90-litre kit is above this. If you are not certain which volume fits the driver and car, call us with the chassis, the driver’s weight, and their height, and we will advise. Lead time on Real Race insert kits is typically 3 to 5 working days from order.

Additional information

Brand	Real Race Seat Inserts
Litre Size	70 Litre

Seat insert kit and cushion guide

These are the two ways to change how a seat fits after you have bought it. A cushion changes your height in the shell. An insert kit moulds the shell to your body. They solve different problems.

Which one do you need

If the seat fits but you sit too low or too high, you want a cushion. If the seat is the right size but you move around in it, or it is a size too big and you want it to hold you properly, you want an insert kit.

Seat cushions

Sold as low, medium and high, and the name is the cushion thickness rather than anything about the seat. It is the cheapest way to fix a driving position that is nearly right.

Type	What it does	Who it suits
Low cushion	Drops you as far into the shell as it goes	Tall drivers, and anyone short of helmet clearance
Medium cushion	The standard	Most drivers, most cars
High cushion	Lifts you up in the shell	Shorter drivers, and better vision over the bonnet

Check headroom before you go upA high cushion lifts you toward the roof, and in a car with a cage and a helmet that is exactly where you have least room. If you are close, measure before you order. Going the other way, a low cushion is the first thing to try if your helmet is touching.

Most of our cushions are made for a specific seat, currently the Mirco Classic, GT, RS1, RS2, RS7, RTS-2 and RTX-7. Check the compatibility on the product, because a cushion cut for a different shell will not sit right.

Seat insert kits

An insert kit is expanding foam and a bag. You sit in the seat, the foam expands around you, and it sets to the shape of your body. It is what single seater and rally teams use to make one shell fit one driver properly, and it is the answer when a seat is a size too big.

Sold for	Litre size	What it suits
Small drivers	30 to 40 litre	A slim driver in a standard shell, or filling a small gap
Medium and small drivers	40 to 50 litre	The usual starting point
Large and medium drivers	50 to 70 litre	More material, for a bigger gap or a deeper shell

The litre figure is the volume of foam in the kit, not a measurement of you or of the seat. More litres fills a bigger gap. If you are between two, the larger kit gives you room to get it right, and you can trim the result.

You get one attemptThe foam sets once. Read the instructions properly, have someone to help you, and be dressed exactly as you will drive, in your suit, with your helmet and your head restraint on and the harness done up. Any layer you leave off is a gap you will feel every time you get in afterwards.

FIA 3795:1992

Six of our insert kits carry FIA 3795:1992, which is the standard for the foam itself. If you are running in a championship that requires an approved insert, check for it on the product. The rest are for road, track day and club use where no approval is required.

A note on sizing up and padding out

If you are between two seat sizes, our advice on the bucket seat guide is to take the wider one. An insert kit is what makes that advice work. A seat that grips your hips cannot be made bigger, but a seat that is slightly loose can be made to fit you exactly, and it will be more comfortable than either the smaller seat or the loose one.

Not sure which fixes your problem?Tell us the seat, what is wrong with how it fits, and your height. Sitting too low, sliding about and being pinched at the hips all have different answers and it is worth getting the right one. Call 0115 989 3488 or email Sales@GSMPerformance.co.uk.

All figures read from our own product data across the insert kit and cushion categories, checked 2 August 2026.

Availability

We stock a wide range of the Real Race lumbar support pump up cushions in various sizes. These can be made available for dispatch within 24 hours.

Specicalist components: Various materials and specialist components are directly sourced from the manufacturer to order. This direct delivery method means that most in stock parts are delivered within an estimated 7-10 days.

Need them fast? Please contact us in advance to check our stock and product availability. we may be able to dispatch them within a shorter lead time. Speak to us in advance to find out how we can assist.

Have you written anything about this exact product?
Yes, we have covered this exact product: Real Race Seat Insert Kits Arrive In-Store For 2026, and Schroth Indi Resin Bead Kit 2026 Guide. That is first-hand coverage from our own builds and showroom, not brochure copy.

Will I fit in this seat?
Send us your height and waist size and we will confirm the fit. The paper dimensions only tell half the story, and our showroom team sit in these seats every day, so you get the honest answer rather than a guess from a chart.

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.

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.

Spread the cost with Klarna

Choose Klarna at checkout and pick the plan that suits you. The options and amounts for this product are shown below.

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.

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