A bucket seat does not bolt to the floor. It bolts to brackets, and those bolt to a car-specific subframe. Getting the fixing type right is what decides whether the parts you order fit together at all.
Two systems, and they are not interchangeable
The fixing type is a property of the seat, not a choice you make. Every bucket seat on the site lists it, so check the seat first and then buy the brackets to suit. A side mount seat cannot be base mounted and the reverse is equally true.
The stack, from the top down
Order in this sequenceSeat first, then brackets to suit the seat, then a subframe to suit the car. Buying the subframe first is the usual way people end up with parts that will not talk to each other, because subframes are made for a fixing type.
Choosing side mounts
Once you know the seat is side mount, these are the things that vary.
We do not publish a hole spacing in millimetres, because brackets are sold to a pattern letter rather than to centres and a wrong figure would send you after the wrong part. Match the pattern named on the seat and the bracket, or send us both product links and we will check.
ABE or FIA
Two approval routes and they mean different things. FIA brackets are approved for competition and are what a scrutineer will look for. ABE is a German road approval, which is what you want on a road car where the seat has to be road legal and where an insurer may ask. Our range carries both, and the adapter type is listed on every bracket.
The side mount standard itself is FIA 8854-1998, and you will see it quoted on the competition brackets alongside the seat homologation.
Car specific mounts
Some brackets are made for one car rather than for one seat. We carry those from PCI Racing, Cybul, Cobra and SW Motorsports, covering the BMW E46 and E63, the Mazda MX-5 NA and NB, the Mini R53 and R56 and the Toyota GR Yaris. They combine the bracket and the subframe into one part, which usually gets the seat lower than a generic pair and takes fewer bolts to fit.
If your car is on that list, look there first. If it is not, you want generic side mounts plus a car-specific subframe from our fitting equipment range.
Things worth checking before you order
Brackets are handed
Driver side and passenger side brackets are not the same part. On a right hand drive car the driver side is the one with the handbrake and the transmission tunnel to clear. Most are sold as a pair, but where they are sold singly the side is listed.
Bolts are not always included
Some brackets come with the M8 bolts and some do not. It is listed on the product under M8 Bolt Options. Worth a glance, because it is annoying to have everything else on the bench.
Height and headroom
A low profile bracket gets you as far down as the parts allow, which matters in a car with a cage and a helmet. A high profile lifts you to clear a wide sill or a tunnel. If you are tall, or you are fitting a cage, start low and work up.
Send us the seat and the carThe seat you have chosen and the car it is going in. We will tell you which brackets and which subframe, and whether a car-specific mount would do the job better. Call 0115 989 3488 or email Sales@GSMPerformance.co.uk.
All figures read from our own product data across the side mount categories, checked 2 August 2026. Fixing type counts are across the bucket seat range on the same date.
