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Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Thu Jul 12, 2018 7:21 am
by jetcat3
How much does the six cylinder Jabiru weigh? 915 iS is about 215 pounds installed.

I can’t wait to see how the 915 iS implemented this year. Oshkosh should be a good place to show them off!

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Thu Jul 12, 2018 12:38 pm
by Scooper
jetcat3 wrote:How much does the six cylinder Jabiru weigh?
The Jabiru spec sheet for the 3300A says the installed weight is 180 pounds.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Thu Jul 12, 2018 7:41 pm
by Mark Gregor
The 3300 jabiru makes 120 horsepower but it’s at a higher RPM where prop is not efficient. That’s why you always see short blades on them.
In actual dyno tests (basically they tie the plane to something stationary and measure the amount of thrust or pull the engine can produce) the 100hp 912 outperformed the 120hp Jabiru.

We traded in a Lightning on a new Astore last year and performance wise it not close to the Astore w the 914.

The 914 feels a lot stronger than 15 more horsepower than the 912. Reports so far (I have not flown it yet personally) is that there is a bigger difference between the 912 and 914 than the 914 and 915.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Thu Jul 12, 2018 10:21 pm
by Warmi
I have very little experience with 914 but I keep hearing two drastically different opinions about the overall utility of the engine.

1) unless you are flying up there in the mountains and/ or have a constant speed prop, 914 is a waste of money

2 ) 914 is awesome and worthwhile upgrade even if you are flying a simple LSA down there at 700 feet...

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Fri Jul 13, 2018 4:06 pm
by 3Dreaming
Warmi wrote:I have very little experience with 914 but I keep hearing two drastically different opinions about the overall utility of the engine.

1) unless you are flying up there in the mountains and/ or have a constant speed prop, 914 is a waste of money

2 ) 914 is awesome and worthwhile upgrade even if you are flying a simple LSA down there at 700 feet...
A constant speed prop would be best, but anytime you can maintain full rated power as you climb it is an advantage. It would even be helpful on these high DA days.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Fri Jul 13, 2018 11:41 pm
by Mark Gregor
Warmi,
People tell me this all the time. I then ask them if they have ever flown behind the 914 and the answer is usually no. Not sure why this keeps going around but I guess a part of it is from manufacturers who do not offer the 914.

I have about 800 hundred hours behind both the 912 and 914 and maybe 300 behind the 912iS. Most of these hours are in Tecnams but I guess it wouldn't make a lot of difference. In same weights and configurations the P2008 climb rate goes from 6-800 w the 912 to around 10-1200 with the 914. This is at 1000 feet. Also gives abt12-14 knots additional cruise speed at all elevations.
Remember this is a turbo charged engine not turbo NORMALIZED like most continental or Lycomings.

When you get up high you have to back out of the throttle to avoid overspeeding the engine. I have flown the P2008 with a constant speed and 914 and it gave an additional 2-300 feet of climb performance and up to 10 additional knots at 10,000 feet. Yes it was better but your getting 80% of what the 914 can do without the constant speed prop. The nice part about it was being able to reduce RPM at cruise so you weren't screaming the engine at 5500 plus to get max speed. This reduces noise and fuel consumption and makes the ride more relaxed.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sat Jul 14, 2018 6:35 pm
by jetcat3

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Tue Jul 17, 2018 6:44 pm
by jetcat3

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sat Jan 12, 2019 9:28 am
by jetcat3
Another update from Trent running a 79” fixed pitch prop on his Kitfox series 5 with the STi wing and 915 iS. He’s been smoking Carbon Cubs around 5,000ft MSL.

https://youtu.be/HP2fAtf3p08

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sat Jan 12, 2019 11:10 pm
by Wm.Ince
jetcat3 wrote:Another update from Trent running a 79” fixed pitch prop on his Kitfox series 5 with the STi wing and 915 iS. He’s been smoking Carbon Cubs around 5,000ft MSL.

https://youtu.be/HP2fAtf3p08
Wow! . . . That was awesome.
Thanks for posting that link.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sat Jan 12, 2019 11:40 pm
by Warmi
jetcat3 wrote:Another update from Trent running a 79” fixed pitch prop on his Kitfox series 5 with the STi wing and 915 iS. He’s been smoking Carbon Cubs around 5,000ft MSL.

https://youtu.be/HP2fAtf3p08

Well,he better be ...the 915is engine costs more than the titans they have in cubs :D

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sun Jan 13, 2019 9:52 pm
by jetcat3
Honestly it’s crazy to me how much a Titan costs! I just don’t think the 915 is so overpriced at 38K. It’s the most advanced piston engine on the market. Yes, it is overpriced but not by much IMHO! I mean it’s already spanking the Titan engine at low elevations and you get all of the added benefits of multi port injection, full power to 15K, and crazy economy when you pull it back. Not to mention it weighs about 50 pounds as installed.

I recently discovered the Zlin Outback Shock Cub. What an amazing performer even on the 914 turbo! I can’t wait to hear back when they’ve test flown the 915 on this bad boy!

https://youtu.be/19niV8VXdQw

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sun Jan 13, 2019 10:23 pm
by drseti
jetcat3 wrote:I just don’t think the 915 is so overpriced at 38K.
Price is relative, of course. But at twice the cost of a 912ULS, that seems steep to me.
it weighs about 50 pounds as installed
I assume you meant it weighs about 50 pounds less than the Titan. I believe the 915 weighs in at 185 pounds. Still pretty heavy for use in an LSA, given that the 912ULS comes in under 140.

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sun Jan 13, 2019 10:28 pm
by Warmi
It is expensive but then again, If weight and prop related restrictions are at some point suitably relaxed then is it gonna make much difference to a guy who is about to shell out 200k+ for his new Bristell or Tecnam ?

Re: New Rotax 915is trubo fuel injected 135 hp

Posted: Sun Jan 13, 2019 11:36 pm
by drseti
Warmi wrote:It is expensive but then again, If weight and prop related restrictions are at some point suitably relaxed
That's a pretty big if (and, at this point, involves a lot of wishful thinking).