Please compare the flying characteristics of a Kitfox 4 and an Kitfox S7 please

[avidflyer]

Perhaps I should have done a search on this before I posted the question, but for those who have flown both, can you make a comment please? This is with both of them having 100 HP 912 ULS engines. If the ground handling is any different with both as taildraggers, please give your thoughts on that as well. Thanks, JImChuk

[68niou1]

Pretty big difference between the two, in my opinion the model IV is quite a bit more narrow and short than the 7 so you really have to be on your game with take-off/landing as it happens right now. It will force you to be a better pilot, It is very responsive. The model 7 is more forgiving as it’s longer with wider gear. Actual flying they fly about the same, 7 will be faster overall unless it’s a STI, my IV was 90-95 mph where my 7 is 105-110. Also with all the changes from the progression from the IV to 7 the cabin is way more comfortable with better sightlines.

[avidflyer]

Thanks for the reply, I suppose I should have been more specific in my first post as well. I should have specified the Classic 1200 Model 4, and added the smooth cowl on both so visibility is similar. Wonder why the 4 would be slower than the 7 if they have the same engine. It would be a good bit lighter. Thanks again, Jim

[68niou1]

Most the 4’s I’ve seen including mine had the round cowl, also no strut fairings or really good gap seals. Also doors didn’t seal as well and fairing pieces just were not as tight/clean in the late 80’s and early 90’s. Just my .02

[Slyfox]

welp. I guess you can't compare speeds between the 7 and 4. At least not mine. I have the model 4 1200. I have the 912uls, clipped wings, big tires 27.5, spring gear. I get 115mph. I have flown with scott with his model 4 1200 that he had and had to pull the power, for he did 90mph. I flew with paul with the black pearl a couple years ago, he had the model 7 with the 912is motor and he also did 90mph I had to pull back about half power with him also. so comparing speeds between the two, well that one isn't true.

[jrthomas]

I think if you compared a model 4 to a model 7 that are identically equipped, the model 4's performance would be superior. It would for sure be superior in climb and stol. Cruise speeds should be pretty close to equal. I have a long wing model 4/1200/912ul with Grove gear, 22" Desser's and a Kiev prop. It has all the Speedster options. I also have streamlined jury struts and horizonal struts. At 5000rpm I get a solid 105mph and at 5500 I get 115+. I can get a solid 1300 fpm climb solo in this cool air. My flying buddy also has an identically equiped model 4 speedster with 100hp. That extra 20 horsepower shows. It's performance is really impressive. Both planes are the 1200 gross weight. I have not flown a model 7. It may be slightly more docile but the model 4 is pretty docile too, especially compared to one of my friends model 2 I used to fly. The model 4 in in a class of its own. The models 1 thru 3 are a different animal and the models 5 the 7 are more refined.

[Slyfox]

I think if you compared a model 4 to a model 7 that are identically equipped, the model 4's performance would be superior. It would for sure be superior in climb and stol. Cruise speeds should be pretty close to equal. I have a long wing model 4/1200/912ul with Grove gear, 22" Desser's and a Kiev prop. It has all the Speedster options. I also have streamlined jury struts and horizonal struts. At 5000rpm I get a solid 105mph and at 5500 I get 115+. I can get a solid 1300 fpm climb solo in this cool air. My flying buddy also has an identically equiped model 4 speedster with 100hp. That extra 20 horsepower shows. It's performance is really impressive. Both planes are the 1200 gross weight. I have not flown a model 7. It may be slightly more docile but the model 4 is pretty docile too, especially compared to one of my friends model 2 I used to fly. The model 4 in in a class of its own. The models 1 thru 3 are a different animal and the models 5 the 7 are more refined.

I have flown my model 4 for about 3 thousand hours, yes you heard it right. originally it was a long wing with the 912ul. Even then it flew pretty fast. upwards to 100mph. Over the years I went and chopped the ends off and it's now a speedster sort of. I still have the dihedral in the wings, which I think also makes the plane. I put electric elevator trim in the elevator, very nice love it. I sealed the gaps in the back and have the ribs in the horizontal and elevator. I also put the IVO prop on both motors with the uls getting the medium in flight adjustable. that has made it possible for short steep take offs and high speeds for cruising. I push the throttle all the way in and set it for 5500rpm. My speeds are accurate, they are gps speeds. calm winds and a direction that is to all four headings. I really love the short wing, very responsive on the bank, I can take off real short and land short, right now I can land in calm wind and easily turn off the runway at 300ft, that's without using brakes. I plan on upgrading my brakes to some newer ones that will work, mine right now are awful. When I do that my short landing will be nice and short. Can't imagine the 7 being much better it weighs a whole bunch more. than again I weigh personally 170, and I'm like 5.6 so the extra room is not needed. In fact I have to have booster seating to see out and reach the rudder pedals. lol

[Jerrytex]

Only have about 7 hours on my KF 5.7 (has some 7 upgrades), but comparing it to my KF 4, the first thing I noticed was the lack of a head ache flying it. Then I realized.... oh, I wasn't whacking my head on the door frame getting in and out of it like I did with my model 4. Ha.

Some other things I noticed, besides no head ache....

More stable on take off. It's is much easier to keep straight while going down the runway before rotating.

The stick forces feel a little different on take off. It seems like my 4 had more forward stick travel than the 5.

On my 4, when I chopped power, the plane would start coming down. The 5 seems like it takes longer to start slowing. I am still working on this trying to get slower on final. But the 4 seemed more "natural" in how it slowed, if that is such a thing? Could just be that I need more time in the 5.

Overall, in the air, turns and actual flying....very similar. Quick and responsive, and oh yeah a absolute blast to fly......

[Newkid]

I've flown both quite a bit. if the gear is set up correctly neither is a handful on the ground. The IV does exactly what you tell it to right when you ask it. The 7 takes a bit more asking. Its still quick on the controls but everything is heavier. The 7 loves to use its trim where you rarely touch the trim on a IV. As I've gotten older, I've begun to love the creature comforts of the 7. The cockpit is quiter and better sealed. I feel like the IV has more leg room if the pedals are set up correctly. The IV will out handle the 7 hands down while still being capable of taking on the same winds and cruising at the same speeds. I own a IV so I'm a bit biased, to me they're the perfect mix