Kitfox 4-1200 vs Kitfox 5 vs 7 vs Super Sport.. Confused

[HiViz]

I have read the Kitfox Model History sticky and have done some research. Here is what I found.. Between the Kitfox 4-1200 and Kitfox 5 there is a 100lb empty weight difference. Between the Kitfox 5 and Kitfox 6-7 there is about a 25-50lb empty weight difference, motor mounts moved forward and interchangeable gear.

First Part: Between the Kitfox 4-1200 and Kitfox 5 with both engines being the same (912s) I know the 4-1200 will have better "performance", but my question is, which model is better during high winds? Presume all the available upgrades from the model 7 will be installed on the model 5 (elevator etc etc).. Is it also possible to install the STI wing, elevator etc etc from the model 7 to the model 4-1200? Or is it only for the model 5-7

Second Part: Between the Kitfox 5 and Kitfox 7 the interchangeable gear does not appeal to me, that being said, it seems to me that the altered location of the motor mounts on the Kitfox 7 is more or less to accommodate CG when adding a 180hp engine. For the 912s it seems the Kitfox 4-1200 and Kitfox 5 compliment the 912s best?

Third Part: Would you rather build a Kitfox 4-1200 or a Kitfox 5 with a 912s? Assuming you can add the STI wing and all model 7 upgrades to the 4-1200 I probably would lean towards that, but I am also assuming that if the same upgrades for the model 5 are not available for the model 4-1200 then it's likely the model 5 would be better than the model 4-1200

Thanks for your time

[rv9ralph]

I’m not sure of your point, but I will comment to your post. In your comparisons, it appears that one thing you have not gleaned from your Kitfox history review is the size of the fuselage in the 5 to 7 is relatively the same. The model 4-1200 fuselage is much smaller, resulting in the lower weight, resulting in the performance with the same engine.

just some more to chew on.

Ralph

[HiViz]

Thanks Ralph! Exactly, you're correct. I was not so much trying to make a point, I was just asking some questions. You're comment shows the reasoning as to why you can add an interchangeable gear option and all model 7 upgrades to the model 5. I was more or less inquiring about the model 4-1200 and model 5 differences.

I was also wondering if you are able to add the STI wing, elevator etc to the model 4-1200, but I'm not too sure as the 4-1200 and 5-7 have a different fuselage.. Another thing I was inquiring is if the forward motor mounts to accommodate more powerful engines in the model 7 are in fact better when using a 912s or are they more or less for 180hp with a CS prop? I would like a fixed pitch with the 912s

[Greg79]

You cannot put the STI wing on the model 4. The model 4 is a complete different airplane. Also there are three different model 4 kitfox. the first is the the model 4 with gross weight of 1050lbs. The second is the classic model 4 with a gross weight of 1200lbs and then the third which is the speedster classic 4. I did a lot a research before buying my model 4 speedster. The 5 and up are a lot bigger and roomier and it was a really hard decision but in the end I had found a really nice partially build kit that in the end was going to save me a lot of money over buying a used 5-7 or buying a new kit. For me I wanted to say I built it. I'm 5'11" and 190 and I think the model 4 fits me like a glove. My Friend who is 6'2" thinks it a bit snug for him but he is used to all the comforts a of PA-38 Tomahawk! Everything you need for a model 4 1200 is also still available from Kitfox as they still sell this model, mostly to Europe from my understanding. Hope this helps.

[Esser]

Thanks Ralph! Exactly, you're correct. I was not so much trying to make a point, I was just asking some questions. You're comment shows the reasoning as to why you can add an interchangeable gear option and all model 7 upgrades to the model 5. I was more or less inquiring about the model 4-1200 and model 5 differences.

I was also wondering if you are able to add the STI wing, elevator etc to the model 4-1200, but I'm not too sure as the 4-1200 and 5-7 have a different fuselage.. Another thing I was inquiring is if the forward motor mounts to accommodate more powerful engines in the model 7 are in fact better when using a 912s or are they more or less for 180hp with a CS prop? I would like a fixed pitch with the 912s


Every engine mount is different fomth engine. Lots of 5s have big motors including of one I know of who an IO360. In fact the shorter nose is better for bigger engines so your thinking is backwards on that. The extended mount on the 7 is so you can actually use your baggage areas total weight with a Rotax before being too far aft from what I understand. The first guys to put a Rotax in a model 5 had to use rear swept get the c of g. I think there have been a few design iterations. If you want a fixed pitch prop and a 912ULS, the 7 mount will be better. Apparently it makes it fly more stable too

in theory the STI wings could bolt onto the 4 but the flapperon attachements and mixer assemble are all different from the 5-7 and would have to be redesigned and tested $$$

Hopefully that makes sense. I’ve been up all night on a midnight shift.

[HighWing]

... The first guys to put a Rotax in a model 5 had to use rear swept get the c of g....

From my memory, the opposite was the the case. The V was designed around the Rotax engines and when using the heavier certified engines, the wings were swept forward a bit. Not sure how much, as my experience has been IV centered

[Esser]

Here is where I got that information from:

https://teamkitfox.com/Forums/threads/355-Feb-09-KOTM-John-King

[HighWing]

I guess we are both right. I remember John from the early email lists. His was a 6 and apparently the engine mount for the 912 option on the 6 was a cousin of the V mount. He mentions that most of the wing sweep was forward to accommodate the heavier engines - likely referring to the Vs - and that was likely what prompted his question to Skystar for the aft sweep possibility, and that to his knowledge his was the only Kitfox with aft swept wings.