When I started to build my vintage racing Elan (which is for sale -- see the
classifieds) from a pile of parts, I was startled to learn that the seat was
supposed to bolt to 30+ year-old fiberglass and the same material was also
supposed to protect me from being T-boned if the opportunity should present
itself. I wasn't willing to accept this situation, so I tried to provide
some side intrusion protection when building the obligatory rollover bar. I
also determined to mount the seat and seat belts to a more substantial
structure. This is what evolved. The whole enchilada weighs just 100 lb.,
so there is a significant weight penalty compared to the "paper clip" roll
bars most racers run.

The entire structure bolts in after the body's on. Other than removal of
the molded-in defroster ducts the body is unmodified for clearance. Many of
the attachment points are original body-chassis bobbins. In the cases where
I needed new attachments, there is an aluminum spacer epoxied onto the
chassis to take up the space between steel and fiberglass. At every point
where loads are applied to the (thin) chassis, including for the seat and
belts, there is a reinforcing plate welded on inside or underneath. The
righthand side of the seat bolts to the chassis in two places, and the
lefthand side to two brackets on the lower side tube. The seat belts also
bolt to the chassis and the lower side tube, while the shoulder harnesses
connect with the brace between the rear suspension towers. Only the crotch
strap is mounted, with a large spreader plate, to the (reinforced)
fiberglass floor.

Two unexpected benefits accrued from having a steel structure under the
dashboard. One is that it was easy to hang the steering column from it in a
manner that allowed the height to be adjusted. The other is that it was
possible to brace the pedal bracket so that deflection when brake force is
applied is minimal.

If you would make a structure like this for yourself, here's some advice.
It's both a lot easier and a lot more difficult to make a bolt-in structure
than one built and welded in situ. You can take things out after you have
tack welded them and get good access for final welding, but then everything
has distorted so you have to bend it back to fit so you can go on to the
next stage. You win a few, you loose a few.

Email Gerry
'66 S3 DHC For Sale