My interest is primarily in the RV-3B, since that's what I'm building.
The new spar they are talking about is the one in the RV-3B.
There might well be more about this topic both in this source and elsewhere, and perhaps a diligent researcher can learn more. If so, I'd be interested in that.
Dave
From "27 Years of the RV8tor," page 382:
RV-3 Wing Update [12/96]
We have static tested another RV-3 wing which included spar modifications suggested by prior tests. This time, results were satisfactory. We have prepared modification kits which we are sending out to all RV-3 owners requesting it. Modification kits for Type II RV-3s have already been sent out. We are now in the process of designing a new spar for use on all future RV-3s, and for retro-fit on under construction RV-3s.
RV-3 Wing Test & Status [1998 1st]
by Van
Late last year we built a set of wings around an all new spar, patterned after the RV-8 spar. Static testing was successful. We loaded the wing to a simulated 9G load and it held, not just for the required 3 seconds, but for many minutes. Then a few more bags brought the house down. Though it would be nice to be able to say that it withstood loads well beyond expectation, it was just as satisfying to see it pass with results extremely close to our calculation.
We are now working or redrawing the wing plans and getting the new spar into production.