Hi everyone:
I would greatly appreciate the benefit of your input on the subject of
putting in a roll-cage in an early Elan for vintage racing.
I know some persons object to stripping an Elan and installing
roll-cages, however, after you have an incident your perspective on this
leans towards caution. And as Rod has observed, I don't want to give up
the joy of driving the Elan to explore its limits (which properly for me
are best done on track). The Elan proved surprisingly tough in one
side-encounter with a tire-wall, nevertheless I want first to make this
cage effective, but if possible also esthetic. TWO QUESTIONS: where
to connect with the chassis, and how.
As now conceived, this will be a welded cage (except for one or two
locations where welding may not be possible). It will be a full-width
cage to allow for an occasional passenger.
My cage-builder and I agree that the head-high (plus) main-hoop behind
the driver will tie into the rear strut towers and the rearmost
body/chassis bolts at bottom of the cockpit.. The hoop itself will have
a cross bar at shoulder height (for side loads and shoulder straps). He
is also recommending triangulation from the midpoint of the sides to the
center chassis.
A front, lower hoop will run across the body under the fiberglass where
the windshield wipers used to be. Passing down the sides it will return
to the center across the floors to tie-in to the chassis flange (which
will be reinforced).
Both main and front hoops will also attach outboard at the floor using a
metal/fiberglass/metal sandwich through bolted (I wonder how strong that
will be)..
Main and front hoops will be connected on each side with three bars for
side protection. Two bars will run horizontally at the top and mid-line
of the door. These will have vertical connections.
The third bar will connect a point on the side of the main hoop 6" below
the top and run at a downward angle to the front hoop, and continue
forward to the front strut tower. I understand the cage-builder's
rationale, this will materially stiffen the cage structure for front-rear
impacts, but I don't like the look of this bar above the door (especially
when it will have to be padded with foam as well.) From the front hoop
to shock tower, this bar also provides a degree of foot-well protection.
I also plan to run a bar from the front hoop along the floor to the
inside front of the foot well and across to the chassis.
At the front and rear shock towers it is planned to weld 3/8" plates,
drilled and threaded for attaching the cage bar flanges. I know some
vintage groups frown on stiffening the chassis this way. At the other
chassis points (reinforced with 1/8" plates) the cage will be through
bolted with AN hardware.
Does anyone see problems with this design, other than it will add weight
and may be overcautious. Can you suggest other ways to connect to the
chassis? Please let me know your thoughts.
Thanks in advance, Ray in Cincy.
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