Turbo-charging the 912ULS

Talk about airplanes! At last count, there are 39 (and growing) FAA certificated S-LSA (special light sport aircraft). These are factory-built ready to fly airplanes. If you can't afford a factory-built LSA, consider buying an E-LSA kit (experimental LSA - up to 99% complete).

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FlyingBliss
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Turbo-charging the 912ULS

Postby FlyingBliss » Wed May 30, 2018 3:32 pm

Has anyone bought an EFI (electronic fuel injection) and turbo-charge upgrade to their Rotax 912ULS from Edge Performance, or, their dealer in Alberta Canada; Bad Ass Power Sports? From what I understand it requires that the owner register the plane as LSA-Experimental, and, it can significantly improve performance (big increase in HP). Jason, from Bad Ass Power Sports, said he recently installed one in a Tecnam P2008 and it bumped the cruise speed up to 150 knots. Any experience on this topic would be greatly appreciated. Thanks.

Warmi
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Re: Turbo-charging the 912ULS

Postby Warmi » Wed May 30, 2018 3:57 pm

FlyingBliss wrote:Has anyone bought an EFI (electronic fuel injection) and turbo-charge upgrade to their Rotax 912ULS from Edge Performance, or, their dealer in Alberta Canada; Bad Ass Power Sports? From what I understand it requires that the owner register the plane as LSA-Experimental, and, it can significantly improve performance (big increase in HP). Jason, from Bad Ass Power Sports, said he recently installed one in a Tecnam P2008 and it bumped the cruise speed up to 150 knots. Any experience on this topic would be greatly appreciated. Thanks.


Yes, right now you need to switch to LSA-E but I , I think, you would also need to placard your experimental to warn people not go any faster than 120 knots - Arion Lightning "wink wink nudge nudge" style ...
I actually msg the owner of the company ( from Norway) and kind of half-jokingly asked him to get TL Ultralight to include his mod on the list of approved modifications, which he promptly took to the TL Ultralight guys ... they said they will look into it - I am not holding my breath but who knows , TL Ultralight already supports another Rotax 912 mod (http://sportair.aero/category/12-epapower/) so who knows ...

On the other hand, there are about 300 EFI toolkits out there , some with , I think 1500+ hours on them and only about few dozen EFI+Turbo .. do you really want to take the risk of basically running en experimental setup like that :)
I remember doing some research and the EFI kit includes key hardware from a company that specifically warns not to use it in any aviation applications because of lack of redundancy ...
Flying Sting S4 ( N184WA ) out of Illinois

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dstclair
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Re: Turbo-charging the 912ULS

Postby dstclair » Wed May 30, 2018 6:56 pm

I'm tempted to go down the Edge Performance path in the future if TL/Sportair will add it to the approved equipment list and I can keep my Sting as an S-LSA. Not interested in the turbo, though, especially given that I'm a flatlander. Might have a different POV if I was in the mountains. The big bore and EFI bump you up to 118hp and if you want to pull the engine off you can upgrade the camshafts, bumping you up to 122hp. You'd get a lot of speed and climb for ~20% hp increase. And you don't get the complexity of a turbo.
dave

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Re: Turbo-charging the 912ULS

Postby FastEddieB » Wed May 30, 2018 7:07 pm

dstclair wrote:You'd get a lot of speed and climb for ~20% hp increase.


I’m a bit indisposed, but I don’t think a 20% HP increase buys you that much extra speed. Climb, yes, since that is a result of excess HP.

I’m forgetting right now if drag increases as the square or the cube of the speed increase. I think drag increases as the square, but power required as the cube.

Professor? Anyone?
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Warmi
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Re: Turbo-charging the 912ULS

Postby Warmi » Wed May 30, 2018 7:19 pm

Pow(x,2) but drag cannot be described with a simple equation like that... the answer is , it depends :)
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Turbo-charging the 912ULS

Postby FastEddieB » Wed May 30, 2018 7:24 pm

Fast Eddie B.
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TimTaylor
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Re: Turbo-charging the 912ULS

Postby TimTaylor » Wed May 30, 2018 7:26 pm

Leave the airplane as is and take-off 15 minutes sooner.
Commercial Pilot Airplane Single & Multiengine Land; Instrument Airplane; Sport Endorsement Airplane Single Engine Sea; Flight Instructor Airplane Single And Multiengine; Ground Instructor Advanced Instrument

Warmi
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Re: Turbo-charging the 912ULS

Postby Warmi » Wed May 30, 2018 7:31 pm

Anyway, I think more likely avenue for me would be to get the 912is installed rather than a 3rd party mod ... of course I bought a used plane but if I had a choice I would go for the 912iS engine ... but hey I am flying so nothing really to complain about heh
Flying Sting S4 ( N184WA ) out of Illinois

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Re: Turbo-charging the 912ULS

Postby jetcat3 » Wed May 30, 2018 9:01 pm

Yeah, I personally would go with the stock 915 iS. I know the owner of the P2008 and it has been a little bit of an adventure to get where he is now.

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dstclair
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Re: Turbo-charging the 912ULS

Postby dstclair » Wed May 30, 2018 9:54 pm

Warmi wrote:Pow(x,2) but drag cannot be described with a simple equation like that... the answer is , it depends :)

There are real world examples that might directionally demonstrate how increased HP improves performance. Airplains has an STC to upgrade 172's from 160hp to 180hp. They quote the performance improvements:
Speed 138mph to 150mph (9%), Climb 750fpm to 900 fpm (20%) and Ceiling 13K to 17K.

This would be for a 12.5% increase in HP. In this case, 72% (9/12.5) of the power increase is realized in cruise.

If percentages hold and assuming a 20% HP increase then one might get a 14.4% increase in cruise speed which would improve a 115 KTAS aircraft to 131 KTAS. Probably a bit ambitious but I'd be surprised if one didn't gain 10+ knots in cleaner airframes. A draggy airframe would limit the improvements.

And, yes, this could present an issue with keeping the plane LSA legal.
dave

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smutny
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Re: Turbo-charging the 912ULS

Postby smutny » Thu May 31, 2018 10:18 am

dstclair wrote:
Warmi wrote:Airplains has an STC to upgrade 172's from 160hp to 180hp.


I had the Avcon STC on a 172 that I was a partner in. It's important to realize that these STC's are for swapping O-320 engines with O-360, not getting an additional 20-30hp out of the O-320. The Pitts I recently sold had a Lycon engine, an IO-360 that from the factory produced 180hp but after Lycon futzed with it was dyno tested at 239hp. The common thought is that making those kind of modifications to an engine generally halves the TBO number (which in itself is arbitrary, but that's another discussion).

A lot of very smart engineers have designed Rotax engines and have taken the brand from the stigma of being unreliable ultralight crap to an industry leader with a line of solid engines. It's pretty arrogant for a small company to think they can improve an engine that has become the gold standard in LSA aircraft. That being said, motorheads are motorheads and every single mode of transportation has a huge modification market behind it. There is nothing wrong with going down the experimental path, but understand that is exactly what you are doing. You are replacing parts of a reliable engine with unknowns. None of these aftermarket modifiers have done nearly the lab and field testing Rotax has done, they just don't have the funding, you are their test pilots and mechanics.

None of the manufacturers will sanction the use of these modified engines in their SLSA's, there is no upside to it. Right now, all they have to do is defer to Rotax in their documentation. Edge cannot provide that support to their customers, and the airplane manufacturer is not going to accept any liability of the changes to the Rotax. ELSA is you only option if you want to upgrade firewall forward with these products.

I've been watching the development of Edge's products. I think it would be fun to modify a Rans S-9 or S-10 to see what kind of performance increases are possible in the aerobatic box.
John Smutny
LSRM - A/WS
Normandy AIrcraft @ S36

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WDD
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Re: Turbo-charging the 912ULS

Postby WDD » Thu May 31, 2018 2:31 pm

Another set of questions:

1) How much does it cost to add aftermarket EFI to a carb 912 ULS?
2) What about parts and support?
3) Redundancy?
4) Weight?

If there isn't a substantial advantage in performance, cost, and weight, then why bother? Even if there is a substantial improvement, unknown reliability is a big question.

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Re: Turbo-charging the 912ULS

Postby drseti » Fri Jun 01, 2018 10:48 pm

FastEddieB wrote:I’m forgetting right now if drag increases as the square or the cube of the speed increase. I think drag increases as the square, but power required as the cube.

Professor? Anyone?


Parasitic drag goes up with the square of velocity. Induced drag goes down with the square of velocity. Optimum L/D ratio (hence, best glide) occurs at whatever velocity the two are equal.

The power required to maintain a given airspeed is a function of where you are on the total drag curve. Except at L/D max, there are two different speeds that require exactly the same power! The lower of the two is the region of reverse command (aka "behind the power curve") where it takes more power to go slower, in order to overcome increased induced drag.
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Re: Turbo-charging the 912ULS

Postby drseti » Fri Jun 01, 2018 10:59 pm

Warmi wrote: right now you need to switch to LSA-E but I , I think, you would also need to placard your experimental to warn people not go any faster than 120 knots


Actually, in the US an ELSA can be modified any way you wish, as long as the mod does not take it out of the LSA performance limits. The Vh limit is defined in terms of airspeed achieved at sea level, on a standard day, at the engine's maximum rated continuous power. Notice that it is not based upon how fast you actually fly.

So, placarding not to fly above 120 kts won't do the trick. Instead, you have to determine what engine RPM would result in 120 kts calibrated (not indicated) airspeed, at sea level, on a standard day (+15 C, 29.92 in hg, zero relative humidity), and then mark that RPM on the tach with a yellow line, and never exceed that power setting except briefly for takeoff.
The opinions posted are those of one CFI, and do not necessarily represent the FAA or its lawyers.
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Re: Turbo-charging the 912ULS

Postby roger lee » Sat Jun 02, 2018 3:32 pm

“So, placarding not to fly above 120 kts won't do the trick. Instead, you have to determine what engine RPM would result in 120 kts calibrated (not indicated) airspeed, at sea level, on a standard day (+15 C, 29.92 in hg, zero relative humidity), and then mark that RPM on the tach with a yellow line, and never exceed that power setting except briefly for takeoff.”

Then what a waste of a turbo and money to get you there.
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