RV-7 Speed Increase

[jetblackaircraft]

So, this is a little bit out there.... but what would you guys say if I told you that when you build your RV-7, if instead of buying Van's wing kit you buy the spars, shear web, ailerons and flaps, and other miscellaneous parts from Van's, but you buy ribs and skins from Jet Black Aircraft and it'll make your RV-7 go 10 to 15 knots faster.

Same or similar cost (Van's wing kit is $6110, depending on what they would charge for the above mentioned parts, I would say between $6500 and $7500 for the Jet Black version.)

Same type of construction. Ribs would be stamped and have predrilled holes. Skins are drilled, cut, and bent. You just drill to size, dimple, cleco, and rivet.

Now for the downside...

The stall speed would increase slightly from 58mph to around 64 or 65mph.

The takeoff run would increase from 500 ft to around 625 to 650 (still respectable).

Just throwing around ideas here. But, by changing the airfoil the drag can be reduced at high speeds to allow another 10 to 15 knots with the same powerplant.

This would increase your range to over 800 statute miles with 200HP.

Anyway, just a thought....

Mike

[hydroguy2]

How many are flying?

Show me the pics and flighttest data.

[brianwallis]

hmmmmm.... sounds interesting..... any more data to be had? Any structural tests? Any flying?
Best
Brian

[jetblackaircraft]

Don't get the wrong idea. This is all just on paper (well on the computer) for now. I understand your situation though, I wouldn't want to be the guinea pig either if it wasn't my design.

Sounds like the consensus is that if it were proven and had a good track record people would be interested.

Who knows, maybe you'll see it at Oshkosh in 09.

[osxuser]

I'd be down for trying it out, if you need a guinea pig, of course I'm at the mercy of my budget for completion time, but for the record, i'm building a -7 tailwheel, with whatever engine I can afford . When are you thinking of having the stuff ready, and will the be a discount to be a tester?

I totally believe in the 'experimental' side of aviation. While your at it, increase the fuel capacity to 50+ gallons for more range

[Bob Axsom]

I have an RV-6A that I have modified a lot for speed without touching the engine or propeller. I just got home an hour ago from the Big Country Air Fest at Abilene, Texas. From this event I can assure you that there are people out there that will pay for speed. I think 10kts is a magic number. The small increase in stall and landing speeds do not mean squat to these folks. As a previous poster has stated there is continuing interest in increased fuel capacity. I fly with two configurations a 24.5 ft wing span and a 21.5 ft wingspan. The 24.5 ft configuration carries 55 gallons of fuel and the 21.5 ft configuration is 3 kts faster. For short races like the one in Abilene this morning I fly with the short wing.

Bob Axsom

[Jerry Cochran]

Originally Posted by jetblackaircraft

So, this is a little bit out there.... but what would you guys say if I told you that when you build your RV-7, if instead of buying Van's wing kit you buy the spars, shear web, ailerons and flaps, and other miscellaneous parts from Van's, but you buy ribs and skins from Jet Black Aircraft and it'll make your RV-7 go 10 to 15 knots faster.

Same or similar cost (Van's wing kit is $6110, depending on what they would charge for the above mentioned parts, I would say between $6500 and $7500 for the Jet Black version.)

Same type of construction. Ribs would be stamped and have predrilled holes. Skins are drilled, cut, and bent. You just drill to size, dimple, cleco, and rivet.

Now for the downside...

The stall speed would increase slightly from 58mph to around 64 or 65mph.

The takeoff run would increase from 500 ft to around 625 to 650 (still respectable).

Just throwing around ideas here. But, by changing the airfoil the drag can be reduced at high speeds to allow another 10 to 15 knots with the same powerplant.

This would increase your range to over 800 statute miles with 200HP.

Anyway, just a thought....

Mike

While we're talking about modifying the wings, has anyone done a "Clipped Wing" RV? I'm thinkin' 70kt stall, 220Kt cruise, 2000' for landing and takeoff...
Chopping 3' of each wing of an RV-8 should do it... Yeah, that's the ticket...
It would give those plastic guys heartburn for sure...

Who will be first? (large smiley here)

Jerry

[captainron]

I've always wondered about using a wing similar to the old American Yankee AA-1. When they changed the wing for the trainer, or AA-1A, the stall speed dropped, but the cruise airspeed also dropped by around ten knots. If you could put this airfoil on the Vans, should be a good performer with 180 hp.

[rocketbob]

Which airfoil are you proposing?

[cytoxin]

maybe this is a good time to sell my spare left wing spar ? thanks ABF