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VG's for Series-7

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Rich L

Joined: 23 Feb 2008
Posts: 63
Location: North Idaho

Posted: Thu May 22, 2008 4:08 pm Post subject: VG's for Series-7

I am installing VG's on my 7 and wonder if anyone has done it yet.  I would like to compare the distance from the leading edge and the number you put on each wing.  They are the ones made by Harrison Designs.  I did what the instructions said but don't have the nerve to GLUE yet. (not testing first)



Any pictures would be greatly appreciated....

thanks

Rich 

Bonners Ferry,ID

darinh

Joined: 20 Apr 2006
Posts: 327
Location: Utah

Posted: Thu May 22, 2008 7:21 pm Post subject: Re: VG's for Series-7

Rich,



Sorry I don't have any information for you but I would also like to add VGs to my 7 so keep us posted on what you find out.

_________________
Darin Hawkes
Series 7
914 Turbo
Kaysville, Utah

Rich L

Joined: 23 Feb 2008
Posts: 63
Location: North Idaho

Posted: Sat May 24, 2008 7:41 am Post subject: Re: VG's for Series-7

I went ahead and installed the VG's and did a test flight this morning.  They worked just about as advertised and the increased stability on TO and Landing really makes it a treat to fly.

darinh

Joined: 20 Apr 2006
Posts: 327
Location: Utah

Posted: Sat May 24, 2008 11:53 am Post subject: Re: VG's for Series-7

Rich,



Sounds awesome...how far back from LE did you end up placing them?

_________________
Darin Hawkes
Series 7
914 Turbo
Kaysville, Utah

Rich L

Joined: 23 Feb 2008
Posts: 63
Location: North Idaho

Posted: Sat May 24, 2008 1:08 pm Post subject: Re: VG's for Series-7

Joa Harrison recommended 10% for the Kitfox.  I put mine a little over 5.1" to the middle of the VG's on the wing.  I put them about 2" in front of the hinges on the stabilizer.  I bought two sets so I put 128 VG's on the wings and 52 on the stabilizer.  My stall went from 39 to 30mph and with 10 degrees of flaps it went from 35 to 25mph.  Slow flight can be done at 35 mph now.  It makes for awesome short field landings and take-offs.

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Sat May 24, 2008 2:48 pm Post subject: Re: VG's for Series-7

 	  Quote: 	
		  Joa Harrison recommended 10% for the Kitfox. I put mine a little over 5.1" to the middle of the VG's on the wing. I put them about 2" in front of the hinges on the stabilizer. I bought two sets so I put 128 VG's on the wings and 52 on the stabilizer. My stall went from 39 to 30mph and with 10 degrees of flaps it went from 35 to 25mph. Slow flight can be done at 35 mph now. It makes for awesome short field landings and take-offs. 	




Wow -- huge number gain. 

I have tried  and add got far less gains, mind you I still have them on.

What model do you fly and how do you calibrate your airspeeds  to give those impressive numbers? 



How long is your take off run ?  How many degrees flaps are you using ? 

Dave

_________________
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Rich L

Joined: 23 Feb 2008
Posts: 63
Location: North Idaho

Posted: Sat May 24, 2008 3:59 pm Post subject: Re: VG's for Series-7

The plane is a Kitfox Series-7 ELSA.  I am not a test pilot and these are definitely not "calibrated" or exact airspeeds.  These are strictly before and after speeds on a Dynon D-100.  It gives a digital airspeed reading and has been pretty close to the overall ground speeds I get on my GPS. (no wind).  If you go to www.landshorter.com and look at the testimonials, some others have had the same success.

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Sat May 24, 2008 5:48 pm Post subject: Re: VG's for Series-7

Rich , I have tested both StolSpeed and Harrison with minimal results. Mind you that was model IV I have.  Mine work but I never seen those kind of numbers.   You should try with a GPS .  Oops  just re read your post , you did use a GPS .



HOw long is your take off roll now ?

Rich L

Joined: 23 Feb 2008
Posts: 63
Location: North Idaho

Posted: Sat May 24, 2008 7:24 pm Post subject: Re: VG's for Series-7

Dont know yet, WX too crappy right now.  I did notice that it lifted into the air much smoother.  Before it kinda lept up.  Now it just gently lifts off.  That could have been pilot technique but I didn't change anything.  I was getting off in less than 200 ft before.  I think it is little less now.  The engine is a Rotax 912uls.  I will try it and let you know.  I have the runway lights measured out here so I know pretty well how long my takeoff run is.



Rich in North Idaho

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Sun May 25, 2008 1:45 am Post subject: Re: VG's for Series-7

Very interesting, 



You will have to give us a detailed report on the Vgs and plane specs--  like weight etc. 



I likely will in time alter mine to see if I can get any gains like that but not holding my breathe.



Have you flight tested your plane now?   how are stalls before and after ?

power on and power off ? 

Dave

Catz631(at)aol.com
Guest

Posted: Sun May 25, 2008 3:31 am Post subject: VG's for Series-7

Dave,

   I have a set of VG's that I am dying to put on my 4 but am not sure  if it is worth it from some of the other guys who have tried it..Now I am seeing  the numbers from the 7 and maybe I will. However you are saying there is no  difference in stall speed. How about cruise? Are you loosing any speed.  Since putting"fat" tires on my Fox I have lost a few mph and would rather not  loose any more (pretty soon a 701 will be faster then me) 

   I put VG's on my previous airplane(Piper Pacer) and it made a big  difference. I would like to have a little more elevator authority without taping  the gap. Maybe VG's on the stab would suffice. Any results on that?

     Thanks!

                                                                   Dick Maddux

                                                                   Fox4-1200

                                                                   Pensacola,Fl



Get trade secrets for amazing burgers. Watch "Cooking with Tyler Florence" on AOL Food.

  [quote][b]

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Sun May 25, 2008 6:19 am Post subject: Re: VG's for Series-7

Dick, 



I lost about 2 mph going from 16.5 x 8.00 tires to the Kingfox 21" tall x 9" wide tires. I was just out this AM with a TAS 90 to 92 mph cruise with a 582 at  6000 rpm (at) 19litres/hour fule burn.  my buddy has  a 701 wiht 912 and cruises at 85 which is hte same pseed i cruise on amphib floats yet he is on wheels so you likely not have any worries there.  

I never lost any cruise  speed with Vgs. I might of lost one or 2 mph on stall speed and can fly in slow flight perhaps a few mph slower that without the Vgs.   Like i said before I have not taken them off yet but the gains were small.  



I think anyone who uses VGs should be forewarned from my experience that your stall characteristics will change.  So go out and try some stalls and not the pansy ones like power off  straight ahead stuff , but yet power on and stalls and departure stalls and approach stalls.  I can tell you that I found  that some of the buffeting that I  felt before was now gone.  And on more aggressive  stalls you will find it breaks quicker and will likely be more prone to drop a wing. You will be able to spin easier as well.   That being said I certainly think that they are neat and might help a bit but when i read claims of  10 an 15 mph stall reductions when i never saw anything like that I have to just look and listen.  Mine are at about 10%  chord including flapperons.  I think  just over 5" if I recall.  I would have posted here last year when I did it if you want to look it up .



Here is a pic of them   http://www.cfisher.com/vg.html



I did get good gains from using harrison VGs for lowering coolant temps here.



Please everyone try them and post your findings. Maybe I am not seeing full benefit that others do for some reason? 



I will tell you that Kitfox VGs from http://stolspeed.com/  come with Adhesive sheets of 2 sided kick ass tape and are a hell of a lot easier to put on than the Harrison ones.



DAve

Fox5flyer
Guest

Posted: Mon May 26, 2008 3:23 am Post subject: VG's for Series-7

Rich, those are some pretty impressive numbers.  Did your cruise speed 

change any?  Can you send us any photos of your placement?  What model Fox 

do you have and what is your empty weight?

Deke Morisse

Mikado Michigan

S5/Subaru/CAP 370+ TT

"The aim of an argument or discussion should not be victory, but progress."

- Joseph Joubert

Subject: Re: VG's for Series-7

 	  Quote: 	
		   



 Joa Harrison recommended 10% for the Kitfox.  I put mine a little over 

 5.1" to the middle of the VG's on the wing.  I put them about 2" in front 

 of the hinges on the stabilizer.  I bought two sets so I put 128 VG's on 

 the wings and 52 on the stabilizer.  My stall went from 39 to 30mph and 

 with 10 degrees of flaps it went from 35 to 25mph.  Slow flight can be 

 done at 35 mph now.  It makes for awesome short field landings and 

 take-offs.





 Read this topic online here:



 http://forums.matronics.com/viewtopic.php?p=184664#184664

Rich L

Joined: 23 Feb 2008
Posts: 63
Location: North Idaho

Posted: Tue May 27, 2008 9:45 am Post subject: Re: VG's for Series-7

Well I have to apologize to all for my erroneous numbers.  I went up today and found my IAS follows the GPS speeds pretty close till I get the nose up into a stall.  The IAS reads about 10-12 mph less than the GPS in the stall.  It is much more pronounced in this airplane than the 182 I had and I didn't compare the two on my initial tests.    Dave had the right idea.  I am still happy with the increased performance and stability.  I am not going to give any numbers until I can be sure they are correct.  Sorry for the screw up.



embarrassed!

Rich

bigboyzt0yz

Joined: 29 Jan 2008
Posts: 29
Location: Centeral Maryland

Posted: Thu May 29, 2008 3:26 pm Post subject: Re: VG's for Series-7

Did you glue them right on or double stick carpet tape? I also would like to know how you selected a placement pattern at the 5.1" location. And what about the Hoz Stab how far back are they and do they follow the contour of the L/E of the Stab kind a swept back. 

 I was interested in putting them on the 4 since the field I fly out of is only about 1000' plus over run. My friend gets in a 800' field with trees on both ends but it is tricky. They would really help him eat up less ground if he could fly that slow (30 pus 10 mph for safety still is really good) Waiting for the new numbers once you post.

_________________
Lee Fritz in Owings Mills Md. 2002 KitFox-IV Classic/912UL/Warp drive taper tip/100% Complete ( Extras Strut fairings08, Grove gear09,) 300 hrs since Aug 07 "Have your feet on the Pedals and keep reaching for the sky".

Rich L

Joined: 23 Feb 2008
Posts: 63
Location: North Idaho

Posted: Thu May 29, 2008 6:03 pm Post subject: Re: VG's for Series-7

I used the Harrison Designs Instructions and he says 8 to 12% of the wing. That includes Flaperons in the Kitfox.  He also said the Kitfox works well with 10% so I didn't want to do any moving or testing VG's.  I put them on with Loctite 401.  I held them for about 15 secs and they are on FOREVER, including fingers if your not careful.  I made lines with a soft pencil on the wings with the template and then placed the VG's on each line.  I put the VG's on the Horiz Stablilizer about 2" in front of the hinges. Harrison Designs website www.landshorter.com is helpful and there is are a few more out there with installation procedures.  Do a (VG's +Kitfox) in Google and you will get a lot of hits Including YouTube movies of VG's in action.



I put 64 VG's on each wing.  The instructions called for at least 50. My takeoff distance was always very short and its about the same as is my cruise speed.  A lot smoother takeoff and landing and greater climb rate.



Good Luck

Rich

dave

Joined: 22 Sep 2006
Posts: 1382

Posted: Fri May 30, 2008 1:14 am Post subject: Re: VG's for Series-7

 	  Quote: 	
		   A lot smoother takeoff and landing and greater climb rate. 



Good Luck 

Rich

	




Rick I have found that I can climb at a greater  Angle of attack. Like i aid no big gains to me but I have not taken them off yet.   I am going to experiment with them.



Here is a picture of mine   http://www.cfisher.com/vg.html

Mine as well as placed at 10%   5.1 " as well.   Also If i remember correctly I  did the first 3 feet of the wing from the tip inward with closer spacing. 

I did mention that I lost buffeting on stall and that is something that could catch a unwary pilot off guard.  TO remedy this I could just remove a few feet of  VGs at the wing root .  I never put them on top o windshield either but that might help a bit as well for lift..



I would look at these as well  http://stolspeed.com/  , they come with excellent  3M adhesive sheets and do not have the sharp edge like the harrison ones do..   They are easier to apply as well. I have never lost one yet with this adhesive tape.  No Way I will glue hem on until I am 100% i want them to stay there. 



Harriosn VGs i had in stock and used some for a cowl mod that dropped my temps . Here are pics and story.

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