The wing is not the only structural element of the airplane that is effected by all up load.
If the statement you quoted was meant to imply that because of the overall wing strength the RV-6 gross weight could be increased, the official published gross weight would have been updated long ago.
Additionally, if you re read the document you attached, you might notice that the RV-8 wing did not fail at 9 G's
BTW I was present for the RV-6 (and the RV-8) wing tests..... I don't agree with the rumors.
The -6 wing failed at well above -9g and the -8 wing failed at 9g according to the released document until it was redesigned.
Vans upped the gross weight by 50lbs when they installed the nose wheel. Do you think they were concerned about the all up gross weight increase effects on anything else? I doubt they did a complete structural analysis for a 50lb increase. History has proven the -a model gear is weaker than the tailwheel airplanes, yet they get the gross weight increase.
The wing area is less on the -6, 110 sqft and at 1750lbs, the wing loading is 15.9lbs/ft. The -7 is 14.8 and the -8 is 15.5. The wing loading is virtually identical until you over gross the -6 and then it falls in line with other vans designs using the exact same airfoil and design techniques.
Vans designed the -7 as a -6 replacement, per their website, why would they go to any trouble to better the capabilities of the -6 and take sales away from the new models.
To my understanding, the -6 and -7 share the same gear legs, same engine mount design, same longeron design, same skin thickness and virtually every part is the same materials and design but optimized for the newer construction techniques. My airplane has .020” tail feathers.
The -6 was designed from the start to be a 150-160hp, 0320, fixed pitch, lightweight airplane and the -7 was designed to be a 180-200hp, 0360, constant speed prop airplane. The power loading, wing loading and performance charts suggest the gross weight was limited to give the desired performance as the limiting factor with the smaller engines and was never revisited after the -7 was introduced. Why would they?
Scott, i know you were there the day the test were conducted. The literature has your name on it. I respectfully ask from someone who was in the room, that flies an rv6 and has more vans knowledge than any of us could hope for, where is the weak link for a 100lb gross weight increase? Thousands of rv6 doing two up aerobatics and exceeding vne with engines that vans could never have dreamed of has proven the airframe as strong as any of the others in all respects.
Help us understand the dangers and stop repeating the same line over and over. Thousands of flying airplanes have proved this line of thinking wrong. Show us were the -6 is deficient and i was yell in from the mountain tops. My -6 has a 320 putting out 180+hp and constant speed prop. It flies, at 1750lbs, very similar to an -7 or -8 at the same weight except with a slightly higher sink rate power off.
The one caution i will make, DO NOT under any circumstances exceed the published aft cg limit of a vans airplane. This is one area, from testing, that i have found should have probably been a little more conservative. The airplane becomes very difficult as you pass the aft cg limit. Just because you can haul it with your new higher gross weight, does not make it safe if you can not keep the cg within range.
I am ready to learn.