I've seen a lot of the discussion regarding 4-point harnesses in the list's
Spitfires. As an active Ferrari racer, I've been to a number of tech
inspection sessions both at the track and at the dealer. The general
thought is that harnesses which do *NOT* go through openings in the seatback
are virtually useless. Why? Well, this may get graphic, so if you have a
weak stomach, hit delete now.
Imagine this ugly, and hopefully unlikely, scenario: You're flying down the
track, or road, at sub-warp speeds when something bad happens - you're
forced off the road, you hit the brake pedal and nothing happens, you hit
debris or oil and lose control, or any number of other similarly ugly
scenarios - and you wind up going head first into a guardrail, berm, or
other barrier. Heck, it doesn't even have to happen at "sub-warp" speeds,
50 or 60 mph (80-96kph) would probably do it. Anyway, when you hit that
barrier, and your body slams forward against the harness belts, your body
weight will want to continue forward and the belts, with nothing to prevent
them from doing otherwise, will slide sideways as your shoulders are pulled
back. In my humble, and admittedly uneducated, opinion, this is only
marginally (if at all) better than a standard 3-point street seatbelt. Now,
if your harness allows you to criss-cross the shoulder belts (i.e. the right
belt connects to the left side of the buckle, and vice versa), then you
*MIGHT* have something that works. Otherwise, a proper racing bucket w/
openings for the shoulder harnesses is the only way to ensure the kind of
control you want and need in a serious impact.
Actually, I can envision another scenario which might work (and I think
someone else mentioned something like this...) - if you install a roll bar
and then weld a harness mounting bar (at or just below shoulder height)
across the opening, *and* you put the shoulder harness mounting points close
together (but not so close that in an impact they pull together and pinch
your neck), it might work.
One last point (which has been made on this list before, but bears
repeating) - BE ABSOLUTELY CERTAIN that your harness mounting points are
strong. In my old 308, there were mounting bolts through the rear shelf
(just behind the headrests) for the inboard shoulder harnesses (the other 3
belts used the existing street seatbelt mounting points). When I had the
engine out for rebuild, I looked at the underside of these bolts and there
was *NOTHING* to secure them (and yes, the car also did not have the proper
seats for these harnesses to work). If the previous owners had ever had a
mishap with the car at the track while using these belts, ouch, I don't even
want to think about it.
These are my stories and I'm sticking to them. ;-)
George P.
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