Pro-Seat Insert Fabrication for Sportscars

Alex Powell from Pro-Seat in the UK has been with us for the last two weeks training us in the art of producing custom seat inserts for sportscars.  These inserts are designed to hold the driver properly in his/her seat, so that they do not move while driving under load.  This has been a challenge for me in almost every car I've put on track.  I'm constantly fighting g-forces and sliding around in my seat.

Note the F1 driver on the screen?  

Alex's father, Trevor, invented this FIA-approved bead-based seat insert in 1992.  I met these two gents back in March through our partnership with BAC.  Pro-Seat have supplied all levels of motorsport including F1, CART, WRC, LMP and much much more.  Many famous racers have been well fitted and protected by a Pro-Seat insert.

Alex began our lesson by showing us the process of 'dry-fitting' a seat.  This is done with the bag of polystyrene beads by approximating the amount of material required by the driver.  A vacuum is pulled on the bag, the insert is installed and the driver put in place.  We used an Atom3 in this example - I've been tired of being thrown around in the stock Atom seat!

With the driver in place, the beads are sculpted around the body and fill in any gaps between the body and the seat.  Driver seat height is checked to ensure he/she is sitting high or low enough.  To be clear, the Pro-Seat insert does need a 'shell' to be molded into to provide it structure.  It is not a stand alone seat.  We use the Atom3 stock seat as our 'shell' for this insert.

 The driver is carefully extracted from the insert and a rough insert remains.  See it below.  This is used as a reference to determine where the beads need to be placed on the final insert formation.

 Trevor is shown below, pouring a two-part resin into the bead bag.  This resin is a glue that holds the beads together and allows them to form to the drivers body and maintain its shape.

When the resin is added, you have approximately 3 hours to form the final insert.  The beads take on a doughy consistency so it becomes quite easy to form and shape.  The 3 hour window gives the insert maker, enough time to sculpt his masterpiece.The rough insert still has the plastic covering that will be trimmed off along with the excess polystrene beads. This rough insert still needs to cure for 12 hours before we can begin our trimming process.

The next stage of the insert construction will remove the excess parts.  First rough cuts are made and then finer and finer shaping cuts are used to create the insert.  Holes are cut out for waist and anti-sub belts.  The insert is then sanded to give a smooth surface for the fire-retardant upholstery.  

The final insert is shown below in an Atom3.  These inserts are seat and driver specific - unless of course you have an identical twin.  An interesting characteristic of the beads used in this insert, is their ability to sustain some deformation yet still recover its original shape.  Pro-Seat often cite the example of Mark Blundell crashing his Indy car in 1997 at Homestead Spring testing.  This crash destroyed his car but the insert was still useable for the remainder of the season.  Not that I plan to experience this benefit, but I am sure glad that the insert offers that level of protection.

Though this insert is a natural product for formula style cars, like the Atom or BAC Mono, it can also be used in traditional race seats.  We produced one for a gentleman with a Recaro ProRacer HANS seat as shown.  See the inserts below.

Recaro ProRacer

Insert for Recaro ProRacer

John races his BMW 3series in SCCA and has found the seat to be uncomfortable as he has some hip pain from a previous accident.  We removed the seat padding and fit him with an insert.  We think that even clients with traditional race seats can benefit from a Pro-Seat insert.  So expect to hear about us offering this product and service for all sportscars in the very near future.