Gee, I guess I never followed this thread after posting.
Regarding straps, what I MEANT to describe was: In order to secure the car to the Kraftsman trailer, tie-down straps attach with the requisite "C" hooks to the rings welded to the deck of the trailer. (I use the tie-down loops on the car as attachment points.) On my Kraftsman trailer, said rings are oriented parallel to the axis of the trailer. Consequently, the load vector is not a straight pull on the ring, but off-axis at an angle less than 90-deg. For rings of this nature, that is not the optimum condition.
My suggestion was to have your trailer builder weld the rings on the deck so that the straps, when in place, will impart a straight pull on the ring, rather than an off-axis pull.
Mike is absolutely correct that a combination of angled and straight straps is the best combination to secure the load.
The most important strap is one which I have failed to install (!). It's the one that is on-centerline with the vehicle and trailer, running from some secure attachment in the center-rear of the car, directly rearward and attaching to the trailer. This is the strap which secures the car from moving forward in the event of a severe braking incident. The physics for this scenario are much better than with angled straps.
Problem is, where to attach this fifth strap to the racecar? I'm still procrastinating over implementing this improvement.
