Project 996 Road Rallye: Part 12

The seats are getting changed on our 996RR build.  The stock seats are worn out and in need of rebuild and reupholstery.  We also decided to replace the shifter and cables.  This was the perfect time to do both.  Of course there were a couple of surprises...

We decided to look for seat options and found some period correct Recaros.  The Cross Sportster CS seats seem to fit the bill.  They are comfortable, work on a slider and will tilt forward with a simple release.  These seats are essentially the same seats found on early Lotus Evoras so remain period correct on our 996.  Recearo seat supply in the US is very lean so we found them from a company bringing them in from Japan.

Though we sourced a bracket that should have made the Recaro slider compatible, it limits the travel forward.  This can be an issue for drivers with shorter legs that need to slide all the way forward.  We will modify the bracket to fix that issue.  In fact we will probably weld in a bracket that is in double shear so that we can make the seat belt recepticle more secure.

Recaro CS + slider + bracket

The stock seats are powered and quite heavy at 59lbs with slider.  Our Recaros with the slider and seat bracket is 48.85lbs.  Lighter by just over 10lbs each.  So that's a 20lb savings with both seats!  We'll take it.  I would have loved to have installed a race-style fixed bucket but practicality was still a requirement.

I'm especially smitten with the gear knob....😁

The Numeric shifter kit with cables has been installed and the car now shifts much better. We installed it at the mid point so the throws are shorter but not too short.  I will drive the car this weekend and will be able to make a proper assessment.

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.