![]() |
They are faster but not the fastest and they are ugly
Faster than stock:
![]() ![]() Fastest for me so far: ![]() Bob Axsom |
On the HR, the same number of ribs are retained but the wing is shorter.
To do this with the -8 you will want to order a custom spar and wing skins, parts without the pre-punched holes. Then your options are less flaps or less aileron. Either way it will land faster and roll quicker than a stock -8 due to the shorter wing. Pick the compromise you want. |
Quote:
Several years ago I spoke to a gentleman who was designing different wing for RV8. Great engineering brainpower was behind it. Since then I've never heard of any progress. |
Look at the whole equation
The Rocket can get away with a shorter wing (which REQUIRES a higher IAS, all else being equal) because the ship has a larger engine. If you do not add a serious upgrade in HP to a clipped 8, the ship is gonna be significantly slower at higher altitudes, as in above 5000MSL, which is not very high.
Remember, every design is a compromise. To get something, you are likely to give up something, unless a wing redesign is also in your plans. Carry on! Mark |
The long and short of it...
Quote:
V/R Smokey PS:My RVX wingspan is identical to the RV6 but with RV4 ailerons. (51" vs 48") Essentially the span and aileron length of a HR2 on a 6 fuselage. I trimmed the RV4 flaps to match the remaining room left on the wing! The span from fuse to tip on the X is within 1/4" of my Harmon Rocket wing span and identical to any stock RV6. Result, best aerobatic RV I have flown yet! |
Quote:
|
Thanks F1 Boss
Quote:
Bob Axsom |
Quote:
|
Nate,
I have a Super Six with clipped wings (7" per side, same number of ribs in the shorter span...much like the HRII wings). What others have said rings very true (as you'd expect from this smart bunch!) Concur with Smokey's recommendation to consult with Van's engineering folks before diving in. Proven concept on the 4/6 wing, not sure if its been done on an 8 wing. My set up is slightly different than Smokey's, in that I have full size flaps and lost the span in the ailerons (guess that means Smokey would be trying to lure me into a rolling scissors, and I'd be pulling into the vertical or trying to drag him up into a flat scissors...eh Rob! ;)) As far as performance goes, as was mentioned, the g limits remain the same with my higher gross weight. That was a key element of the design feature, from what I've been told. If you're not going heavy (big motor), not sure you need to go that route. If just seeking higher g limits, I'd also find out from the engineers if other parts of the plane will tolerate higher g (tail, etc). If you're just seeking more safety margin at max g...perhaps that's a valid reason...but I think there is a good safety margin there if well built and maintained. I've found that the clipped wing g-limit-saving design feature does cost in high altitude performance. At Airventure Cup 2010, Mark, Wayne Hadath and I climbed to 15.5K, then Wayne went up to 17.5K. At 15.5K, Mark (with his EVO Wings) slowly walked away from me (at that time we were very evenly matched at SL). Wayne (with the same wing as me) lost even more top end at 17.5K and fell back, then descended. I tend to cruise at 12.5 to 13.5 for best effeciency...and that sweet spot altitude would likely be higher with stock wings. So I pay a little in specific fuel consumption there. Flat tips will likely buy you some speed (mine added 3 kts, and upped the stall 5 knots); should add roll rate (as Bill said) but cost in highter bleed rates in a turn or vertical maneuver. I use the flat tips for SL racing with fewer turns. I'm intrigued by Bill's fences...if they preserve stall speed, that's a bonus (Bill, how are they at bleed rates under g, and did they add any top end?) The good news on flat tips, is you can go back to stock, which I did for the turning races at Reno (still bleeds some there though). Here's a few pics. First is Mark and I at Reno, me with stock tips: Here's a pic of us at Macho Grande (Marks place near Taylor, TX): ![]() Pretty stubby with clipped wings and flat tips, eh! Its a bit skewed because I'm a little closer to the camera in the first pic, and a little further away in the second, but it gives some perspective. Just for fun, check out this tip design, by a guy here in Reno: ![]() They are called Scimitar tips, and Eric's website is here. Eric said they are optimized for turning...very little bleed under g. Would they work at RV speeds?...not sure. Eric thinks there may be some benefit. Bet I get Bob Axsom's juices flowing with that one though! :D Finally, of the Super 8's I know of, I don't believe any have been clipped. Kahuna has those long-range tanks in his :), and I imagine standard-length wings keeps his maneuvering wing performance closer to that of the other Team RV aircraft as well. Kahuna, any structural mods to the wings, other than the tanks? Interesting topic Nate! Cheers, Bob |
Say Bob...
...are our tips on my -10 not fairly close to being of Scimitar design? Those and also the two seaters with the "batwing" type tips?
Best, |
| All times are GMT -6. The time now is 01:19 AM. |