Vg,s

[Flybyjim]

I am about to start my wings on the SS7 and was wondering about others experiences on the application of VG's on their wings with and without the laker leading edge, I fly a Rans S-7 now and there was a huge advantage to stall speed and reaction of the wing to the better once I installed the VG's. I used North west aero Vg's on the Rans.

[Av8r3400]

John McBean has stated there is little if any benefit from their extensive testing.

IMO, what makes VGs effective on a "conventional" wing is the flow they promote over the ailerons and flaps at high angles of attack. The wing on a Kitfox has less chord than on your Rans. The longer chord benefits from the VGs. With the Kitfox design, the flapperons are already in high pressure air, below and behind the wing, which maintains their lift and effectiveness when the wing is at a high angle of attack.

[PapuaPilot]

I would agree with Av8r3400 that VGs aren't going to help much on a Kitfox because of the flaperon that is separate from the TE of the wing.

The other place VGs are typically used is on the bottom of the horizontal stabilizer. They help keep the airflow attached to the elevator, which can give lower stall speeds. Has anyone tried this on a KF?

[DesertFox4]

The other place VGs are typically used is on the bottom of the horizontal stabilizer. They help keep the airflow attached to the elevator, which can give lower stall speeds. Has anyone tried this on a KF?

Phil, we've seen this done many times and with good results.

[herman pahls]

I tried VG's on my model 2 with no seat of the pants improvement to stall speed.
Maybe due to the under cambered wing.
Maybe better control response near stall.
I sent them back since they had a money back policy if not satisfied.

My model 4 came with VG's so I do not know the before and after results.
I am curious what other owners are saying about VG's on their model 4-7

[av8rps]

I agree with what AV8R3400 says about VG's on the Kitfox. In fact, I think he nailed it with his explanation.

I say that because the Highlander benefits greatly from VG's. And I'm pretty sure the top of the airfoil is the same as the Kitfox. But the Highlander wing chord is much narrower than the Kitfox.

So the only real difference is that the Highlander uses standard flaps and ailerons vs flaperons on the Kitfox.

Just more testimony to the effectiveness of flaperons :)

[tomec]

I found it much more stable near stall speed Kitfox 4 1200

[Totophe]

Hello,
I have just installed some Stollspeed VG's on my Classic 4 and made a first test flight yesterday.
They are positioned the tip touching the front spar, spaced 6cm from fuselage to 1/3rd of wing and then one between each rib (11cm).
Here are the results. No noticeable cruise speed change (90mph @ 4800rpm)
Stall speed flaps up came from 43 to 38mph and full flaps from 36 to 30mph.
Besides, I put some under the stabilizer 4 inches before the elevator and there is a much better authority for the full flaps flare. So, all this:) improved the stol cabability.