SS7 or STI?

[Pushboy]

Hi -- I'm still considering ordering a kit and I thought I'd ask for some advice.

I'm not sure which is more suitable -- the SS7 or the STI version. I live at about 300' ASL and fly mostly to grass strips and local airports (=5hrs). I'm currently using club aircraft to do this, and would continue with a kitfox with the addition of a yearly cross country flying trip -- hopefully to include some backcountry or out or the way places.

This fall I got my float plane rating -- which, where I'm from here in Ontario, Canada is "bush flying"... I could see myself putting any kitfox I own on floats, at least for part of every year -- it really was a ton of fun!

I'd like a kitfox with a rotax 915, (I like the idea of fuel injection and turbo) but I have flown a 914 at S&R.

Given those ideas -- I'm looking for some advice. Has anyone done a regular SS7 with a 915? And/or put it on floats? Given my hopes to go on one longer cross country a year, would this be a good option? What about on floats? How about the STI version, would that suit better? On floats?

Thanks in advance for any advice.

[Okent]

I would reach out to Paul at S&R. I went there in July and picked his brain on my build. Settled on an Edge 914 with CS prop.
His advice was that unless we were going with the STI wing then the 915 wasn't really worth it due to weight.
Since you're thinking of adding floats it may make sense for you but I would sure give him a call.

Tom

[Pushboy]

Thanks Tom,

I will reach out to Paul and ask his advice.

Incidentally -- you went with an Edge 914 -- is that a 914 with Edge FI conversion or is there more to it than that? You mention a CS Prop-- the Airmaster? I'm only asking as I was hoping for a single lever control with both FI and Turbo.

Thanks again for your help.

Dave.

[Okent]

Yes, went with a 914 with the Edge EFI and an Airmaster propeller. I flew a 912iS with the Airmaster and it was really nice.
My buddy flew the fixed prop carb'd 914. It burned a ton more gas.
I have a carb'd Flight Design CTLS and it burns over a gallon more per hour than the fuel injected models.

I agree that a single lever option would be nice but I just don't know of anything out there.
The Airmaster is dead simple to use and seems to be well supported so just went with that.

[aviator79]

I have a 914 with Edge EFI, Airmaster prop and standard SS7 wing. I would not change anything about it. The SS7 wing is plenty capable of STOL. It's not *quite* single-lever, but how hard is it to click over to Cruise on the Airmaster?

[Pushboy]

Thanks for the replies -- I spoke with Paul at S&R and he echoed the same. He mentioned that once I fly behind the 915 and the STI wing I'll want one... but to ask myself how many high alt, less than 500' strips I'm going to. Given my mission, I think I would be better suited to setups like you guys have described, and what Paul also described.

I am curious though -- as two of you wrote with the same engine set up. It seems that I'm not the only one who wants FI and Turbo -- I'm wondering why you guys went with 914 and Edge FI. Only asking, as this combo of FI & Turbo could be achieved with 912is and Edge Turbo, or Edge 912STi -- unless I'm not understanding correctly. Is one combo better than another?

Thanks again for the info.

Dave.

[aviator79]

I went with the 914 because I live at 7200, and really get my money's worth from the turbo. Decided to add the EFI after the fact.

[patrick.hvac]

Thanks for the replies -- I spoke with Paul at S&R and he echoed the same. He mentioned that once I fly behind the 915 and the STI wing I'll want one... but to ask myself how many high alt, less than 500' strips I'm going to. Given my mission, I think I would be better suited to setups like you guys have described, and what Paul also described.

I am curious though -- as two of you wrote with the same engine set up. It seems that I'm not the only one who wants FI and Turbo -- I'm wondering why you guys went with 914 and Edge FI. Only asking, as this combo of FI & Turbo could be achieved with 912is and Edge Turbo, or Edge 912STi -- unless I'm not understanding correctly. Is one combo better than another?

Thanks again for the info.

Dave.


I would think this has a lot to do with time in the market. The 915is has really not been around that long (2017 for OEMs). I don't think I've even seen a FP version around (group 2 engine I think?)
914 are easier to come by due to heavy drone use and therefore more popular as they pop up on the used OH market. Grab one on a rebuild and pop an edge FI kit on it and you are most of the way to a 915 at a lower price point without the MT prop.
So many aircraft in this weight class do great with 100HP so the extra juice isn't worth the squeeze for those on a tight budget.
I would think that in time the 912is/915is will actually phase out the 914 and UL/ULS models. No doubt full FADEC engines are dominant in the future.

If you're near YOW i would think you prob want floats and are planning mostly close to sea level ops. A 912 with edge FI or an IS model would likely be a great performer. Compare maintenance, TBO, up front capital, mission, etc. You will have to decide what's best for you. Want vs Need I guess. There is always the 'why not' argument..
Gary running off simcoe with a 912 on aerocets looks like he does just fine without a 915.
Just my .02

[Okent]

Dave, if I remember right the Edge FI 914 was a little lighter and cheaper than the 912iS setup.
A 150+ hp engine sounded nice but after flying what we did the 914 was plenty.
If Rotax made the 914 with fuel injection I would have bought it but they won't sell those to us mere mortals.:cool:

[aviator79]

Dave, if I remember right the Edge FI 914 was a little lighter and cheaper than the 912iS setup.
A 150+ hp engine sounded nice but after flying what we did the 914 was plenty.
If Rotax made the 914 with fuel injection I would have bought it but they won't sell those to us mere mortals.:cool:

I agree there is a hole in the Rotax Lineup for a 100HP, turbo, fuel injected engine. There are many planes that don't want the weight and don't need the HP of the 915.

[VictorV]

I have not started my build yet but the Edge EP914Ti is at the top of my list. It's a turbo with FI and costs the same as a stock 914 and even weighs a bit less.
The Edge products void the Rotax warranty but Edge offers their own warranty that's almost as long. I chose it for the following reasons:

1) Has FI so I don't have to worry about carb icing
2) Lower fuel burn
3) Turbo, so full power up to 15,000 ft
4) Cost is $6k less than 915is
5) TBO for 914 is 2000 hrs whereas 915 is 1200 hrs since it's a new product
6) Weighs 40 lbs less than 915is

Choosing between the SS7 and STi is really a matter of mission. The takeoff/landing roll of the STi is about 50% of the SS7 but the SS7 is
still low at 290ft. The cruise speed of the STi is 105 mph and it's 123 mph for the SS7. For me, I'd like to have reasonable STOL performance but enough
speed to get somewhere in a reasonable amount of time. For those reasons the SS7 is my choice. You'll have to decide which is more
important: Speed or STOL.

Victor

[Shadowrider]

Nice summary and I have to agree with all your points. One other thing to consider is the STI does better at higher altitudes also. I have had mine up to 17500 and flew no different than 5k. Living in Utah and having no desire to go anywhere, we went with the STI. I am also partial to the looks of STI wing. If you plan on doing cross country flights then I think the 7SS is the way to go. And remember no one ever says I wish I had less power.