I did that installation two years ago. It was difficult and not optimum
for the Tiger chassis. The front section of the roll bar which supports
the major load is directly above the frame and supported by the shelf sheet
metal(good). Two of the (front) bolt holes are easily installed. The
third hides inside the shelf box is very difficult to get at (but not a
major concern). The rear supports are the problem. They are easy to
install but are only support by 20 ga. sheet metal. The backing pieces are
2.75 x 4". There is the problem. There is no good frame support for the
rear of the roll bar. The sheet metal will take the load and distribute it
to the surrounding area (if it does not rip through). The rear supports
are 2 inches from the driver's side frame and 4 inches from the passengers
side. I was very apprehensive about this but installed anyway.
Conjecturing how the roll bar may function, the load would be vertical
(down) and rearward. The front mounts would not have a problem, the metal
is directly above the frame and about 2 inches is the most it should
deflect. The rear could totally colapse depending on the load. The rear
member towers add a lot of design support (shocks are mounted here) and
argument can be made it may hold. It would be ideal to add a major
structural component here but not possible because of the rear member and
axle.
As my car is up (rotisserie) for repairs, I decided to address this by
adding a 1/4 plate from the frame to the driver rear roll bar. Even that
two inches seems a long way to support off the frame. The passenger side
is way too far at four inches. I installed a large reinforcement plate
formed to the axle well and self distributing the area to 6 x 10 inches. I
don't think this is ideal and favors the driver in protection.
The better sollution would be to modify the rollbar to direct the rear
supports directly into the rear frame. This can be done ENTIRELY above the
rear deck as the rear frame passes through the area and a simply angle
attachment would be ideal. No rear plates or underneath mounting would be
required.
Originally I installed bolts facing upward, with locking nuts on the inside
and then carpet with grommets. Then for 'events' I could drop in the roll
bar. This worked pretty nice. During my 'improvement' I added captive
nuts underneath (bolts now go down).
Earlier I said the 3rd (front) mounting bolt was not important. The front
is supported by a plate extending from the side two bolts (captured), over
the shelf and a third bolt buried inside the shelf. The plate takes the
collision and distributes it to the shelf (frame below). The bolts only
capture the plate to the shelf. The load is vertical (no shear). Unless
the roll bar is in tension, the third bolt is not a factor. Yes with
forward motion, and a collision, there is a possibility of tension, but not
much of the equation considering the rear support in this situation. So I
did not even worry about the 3rd front bolt which would have required a
unbelievable effort to install for zero benefit.
My next improvement will be to use a ZX-3 style roll bar(s) using the shelf
support (adequate) with a rear support tied to the frame. Should be easier
to install than my current set up (and more effective).
Curtis in Santa Clara
B9470844
At 09:20 AM 1/24/00 -0800, Jay Laifman wrote:
>
>
>
>Yikes! Where did the other end of those bolts go? Previously I carefully
>measured and placed my roll bar and drilled through the holes into the
>deck. I pushed through the bolts. This weekend, I finally went underneath
>to attach the plates and nuts. I was able to get everything on except the
>front bolt which disappeared inside a boxed section of the body. There are
>oblong holes through which I can see the bolt. But, they are not in the
>right place, to push up a socket with the nut on it. What do people do?
>
>Should I use a hole saw to cut a hole right underneath? Also, on the two
>bolts on the front right side, next to the battery box, those seem down
>right impossible. Even if I could get the nuts on - which I think I might
>be able to do, there is no wrench in the world that's going to get in
>there.
>
>Anyone been here done this before? Any suggestions?
>
>Finally, the instructions say not to worry about the pressed ribs in the
>steel, to just compress them. Does this bother anyone else? I bought some
>fender washers in the hopes of bridging the gaps. But, the way the ribs
>fall and the holes, they really won't work well.
>
>Thanks, Jay.
>
>
>
>
|