Is there a good way to measure chassis flex?

I drove my brother's new spec car last weekend and it is much stiffer than my car. They are set up nearly identically: 83 body with m030 sways, konis set the same, 350 lb springs, Delrin bushings in the front, strut tower bars, weights within 50 lbs, bolt in style cage (his is welded in, though, and a safety designs cage while mine is an auto power and not welded.

Since the car has been raced and DE'd for about 8 years I suspect the chassis may just be old and worn out but I'm not sure how to test it- any ideas?

I would venture to guess that the welded cage has a huge impact on this seeing as how that is the major difference between the two cars. I don't know if there is an adequate way to measure the difference, but welding footings between bar ends and mounting points should do a much better job at resisting torsional forces on the chassis over a simple bolt in design. That is a pure gut instinct judgment though.

Could one measure flex by jacking up various points, one at a time, to measure other points down to the floor? That "might" work by showing how much movement, at one point, compares on the other car as measured at various places on the chassis.

Of course, you might want to take original measurements on both cars and mark the measurement points to be consistent.

I dont buy the worn out chassis...bent possibly, cracked perhaps. I have raced a lot of 944s with big HP and never really seen that.

Bolt in cage, especially to the weak floor, is junk. A properly welded cage is like adding a second tube frame chassis. In fact one of my 944s was more tube frame than unibody and it was stiffer than a Freshman on prom night

Now there is a mental picture!!!!!!!