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Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Fri Jan 26, 2018 9:43 am
by jetcat3

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sun May 20, 2018 3:59 pm
by jetcat3

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 12:49 am
by roger lee
All this sounds good, but the 915 can only use a constant speed prop due to its shaft design for oil flow through the shaft to the prop flange. This means no LSA.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 8:29 am
by Warmi
roger lee wrote:All this sounds good, but the 915 can only use a constant speed prop due to its shaft design for oil flow through the shaft to the prop flange. This means no LSA.


I think they are working on the non-constant prop version and in any case, if more power is desired, one can always go for a cheaper version at http://badasspowersports.com ( as long as it is an ELSA)

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 9:18 am
by dstclair
From what I understand, the Edge Performance 912ULS turbo is around $30K with a crate-new 912ULS. Interesting option for those wanting a turbo.

I'm actually a bit interested in their big bore and EFI. Don't know that I need the 18 hp but, heck, it's only $$$. Now all I need to do is find a few thousand lying around.... :D

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 9:29 am
by Warmi
dstclair wrote:From what I understand, the Edge Performance 912ULS turbo is around $30K with a crate-new 912ULS. Interesting option for those wanting a turbo.

I'm actually a bit interested in their big bore and EFI. Don't know that I need the 18 hp but, heck, it's only $$$. Now all I need to do is find a few thousand lying around.... :D



Actually TL Ultralight already supports in their Master List of Equipment alternative Rotax engine modifications :
http://sportair.aero/category/12-epapower/

I don't know of any other LSA manufacturer that is willing to risk it - in this case, the SA-R915i engine ( 130 HP) is ridiculously expensive at something like 60K so it is not practical at all ... but I am surprised that they allow it in the first place ( since I am sure Rotax is not going to endorse that )

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 12:51 pm
by MrMorden
It's sounding like Rotax is touting the "single lever" power + prop control to get away from having a separate prop control. I suspect they are going to petition the FAA for an exemption to the LSA rules based on the fact that a single lever config adds no operational complexity and thus no more pilot workload.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 12:56 pm
by Warmi
MrMorden wrote:It's sounding like Rotax is touting the "single lever" power + prop control to get away from having a separate prop control. I suspect they are going to petition the FAA for an exemption to the LSA rules based on the fact that a single lever config adds no operational complexity and thus no more pilot workload.


So this "single lever" props is basically a prop with a simple switch where you can pres-elect different cruise/climb pitch stages ?

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 1:56 pm
by MrMorden
Warmi wrote:
MrMorden wrote:It's sounding like Rotax is touting the "single lever" power + prop control to get away from having a separate prop control. I suspect they are going to petition the FAA for an exemption to the LSA rules based on the fact that a single lever config adds no operational complexity and thus no more pilot workload.


So this "single lever" props is basically a prop with a simple switch where you can pres-elect different cruise/climb pitch stages ?


No, the prop control is fully controlled by the computer in response to engine power setting. There is one "power" lever, that controls both the engine RPM and the prop setting. There is NO other prop control. It's literally the same operation as a fixed pitch prop.

I'm guessing the mapping does something like going courser in the 55-75% power range, and then going very flat above 80-90%. That would optimize cruise speed in typical cruise settings and optimize climb in full power takeoff and mid-course climbs.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 2:28 pm
by Warmi
Ok makes sense- sort of like our semi-smart carbs hehe...
Btw the way FAA operates , by the time a petition like that gets approved/rejected, the issue in question probably will no longer be relevant ...

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon May 21, 2018 2:31 pm
by Wm.Ince
MrMorden wrote:I'm guessing the mapping does something like going courser in the 55-75% power range, and then going very flat above 80-90%. That would optimize cruise speed in typical cruise settings and optimize climb in full power takeoff and mid-course climbs.

And with 0% power . . . the prop would feather, to reduce drag, in the event of total power loss.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Wed May 23, 2018 10:06 am
by jetcat3
Yes, this is what Kitfox is using on the STi as well as the SeaRay. Seems like a pretty cool system!

“He also explained that (perhaps surprisingly to some readers) the 915iS compression ratio is lower to allow for the turbo boost. “Stress is actually a little less therefore with the turbo engine,” he said.

Rotax’s 915iS uses the same displacement as the 912iS. In a weight-to-power comparison — grams per kilowatt hour — fuel consumption is only about 6% higher in the more“On the point about an in-flight adjustable or constant speed prop, Rotax Aircraft Engines top boss Thomas Uhr made an important statement when I asked about fixed pitch props on the 915, “All our engines can use fixed pitch props.” As a leader of a public company, he spoke carefully, but the suggestion was clear: Yes, a fixed pitch 915iS is coming, although today the engine is only driving an in-flight adjustable prop.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon Jul 02, 2018 10:22 pm
by Coloradoeasyrider
I would love to see this engine on a Arion Lightning. Any ideas out there if it would fit?

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon Jul 02, 2018 10:33 pm
by Warmi
I think you should ask directly Nick Otterback about installing 915is ... when I was looking at Arion LSAs he was very responsive and replied to my emails rather quickly.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Mon Jul 09, 2018 5:34 pm
by MrMorden
Coloradoeasyrider wrote:I would love to see this engine on a Arion Lightning. Any ideas out there if it would fit?


It’s got to be smaller than that big six cylinder Jabiru, it should fit, but not sure how the weight & balance would work out.