IVO Light vs Med - Kitfox Speedster

[kshogan]

I'm debating the Light vs Medium inflight adjustable IVO prop for my speedster. Seems to be a bent towards the IVOs in this forum, so I thend to follow whats working.

My question is should I use the Light or Med version. I've read comments about the mediums great descent characteristics, but little else about picking which one. My Speedster is has an 80hp Rotax (considering an upgrade to 100) so I'm curious as to others perspectives.

Thanks!

[DesertFox4]

Kelly, the Medium Ivo may be too much prop. for the 80 hp 912 Rotax engine.
Most go with the Ivo Light on the Rotax 912 80 hp. engines and in fact I can't recall seeing an Ivo Medium on an 80 hp Rotax.

You can successfully use an Ivo Light on a 912S also if you want an Ivo on your 80 hp. now and upgrade to a 912 S 100 hp. Rotax in the future.
I think the Medium is an all around better choice for the 912S engines but I am having good luck and great performance with the Light on my 912S and of course the Light is less money.
I will say that the 912S 100 hp. is about max for the Light prop. to handle.

Recap:

Rotax 912 80 hp. = Ivo Light

Rotax 912 S 100 hp. = 1st choice - Ivo Medium
2nd choice - Ivo Light

[sdemeyer]

Sorry to bring up such and old thread but.....

What prop diameter for the the IVO - light in-flight adjustable are most using? This would be for a 912UL 80HP.

Thanks,
Scott

[Av8r3400]

Mine is a 72".

[DesertFox4]

72" on my 912S 100hp model 4. Works great.

[N82HB]

If you plan on 100hp I'd plan on a Medium. I had a Medium on a little 582 and it worked great with only 64hp. I am sure 80 hp will turn it just fine, and then you aren't limited later.

Kelly

[kitfox2009]

I presently have a 68 inch GSC prop on my Model 5 Vixen long wing with the 80HP 912 engine. I will be replacing the prop soon and would appreciate suggestions from this great team of experienced Kitfoxers. I am considering IVO IFA (ultralite or medium?) What size? How about a Kiev or Cool prop? Does the IFA feature actually make much difference to a Kitfox?
Any ideas would be useful. I don`t really want to collect a "hanger full of props" just like some folks have a "garage full of drivers&putters".
Thanks for your input.

Don

[DesertFox4]

Ivo ultralite for the 80 hp. Rotax. 72" in-flight adjustable.


Does the IFA feature actually make much difference to a Kitfox?YES.

Make the Ivo your first prop purchase and you won't end up with a wall full of aviation "art" like everyone else.

[Peteohms]

I'm just sorry but my $500 3 bladed GSC wall clock looks just fine in my office. My IVO Ultralight also looks and works nice on my Kitfox III with early 912. It's the prop IVO recommended. Call them. They won't let you choose the wrong one.

Pete

[kitfox2009]

Hello fellow KF`ers

I have recently taken Steve`s recommendation in order to avoid excessive "hanger art".
Just today I flew my new 70 inch IVO Patriot in-flight-adjustable and WOW what a difference!! This wasn`t the best test day weather wise for accurate performance figures but I am sure the difference will be spectacular. And super smooth, no vibration at all.
I get full rpm on take off and just "course things up a bit" once off the ground. Climb is super.
As near as I could tell the cruise at 5000 rpm is about 118 mph. This is almost 20 mph better than my old prop.
I will post more accurate numbers after I have flown it more (and on a better day)!!! Thanks, Steve and others who responded to my enquiry.
Don

[DesertFox4]

Another Ivo convert. Good results Don. Now you'll get to see the all performance your Kitfox has to offer. Follow his instructions in regards to prop. bolt torque and tightening after flying the first time. Have fun.

[kmach]

Hi Don, Good to hear that you like your new prop, I too am considering the IVO inflight adjustable . I am looking forward to hearing more about your testing and results. Kevin

[kl2657]

Ok I'll bite... If I were to get an IVO prop for my Speedster with a 912ul 80hp, what's the appropriate diameter? The folks at IVO recommended an Ultralight prop with a 70" diameter for my plane, but I see a few of you are using a 72" prop. Any thoughts?

Also, how big a benefit is the IFA feature over the ground adjustable?

Thanks,

Jason

[kitfox2009]

Hello Jason
From my limited experience the key to prop performance is the IFA feature. It allows you to achieve maximum RPM (horsepower) at any time and also provides economical and efficient cruise speeds. I run a 70" Ultralight on a 912UL Model 5 Vixen.
Don

[DesertFox4]

Jason, when I had a 912 80hp. Rotax I ran the 72" prop. Worked great but the 70" works just fine too. I think Ivo knows pretty well what works now on the various Rotax engines. I went from a GSC wooden 3 blade to a 3 blade Ivo and the performance was .......incredible. Much smoother too.

The IFA is really a plus if you don't have to worry about Sport Pilot rules. If I had to go Sport Pilot I'd still use the ground adjustable Ivo. It takes all of two minutes to adjust the pitch and go try your setting. No protractors to mess with and all blades adjust evenly at the same time. In a word, simple.

With the IFA you can get max rpms for most horsepower for shortest take offs and as you push over to level flight just roll in some pitch and watch the speed increase. Pull the throttle back just a little for approx. 75 to 80 percent power , adjust the rpms where you are comfortable (between 5,000 and 5,500) and have fun. The Ivo is the simplest IFA I've ever seen. The blades are about the strongest on the market and performance is always up there or better than the rest for usually less money.
I've flown about 1,600 hours behind them now. Most of my local friends fly them after trying many brands.
That's my 2 cents on props.

[Dorsal]

I am curious as to the benefits of IFA, it seems cool and I would love the justification to upgrade but my conclusions are as follows. I currently have my prop pitched for cruise so I do not expect to see any improvement and my speeds seem comparable to others. My impression is that the principal advantage of the IFA would be to shorten my take-offs or improve climb rate. As I am (currently) only using airports (vs. off airport) and have yet to use a significant fraction of the available runway the value of shortened take-off role seems limited. Better climb would occasionally be nice and I expect be much more noticeable if I did more flying near max gross weight.
All in all I can't justify it but maybe someday:)

[cainbird]

I have always been the biggest critic of IVO props. My friends have always run them but I always preferred the look of say the GSC or Powerfin. I have bought several different props over the years but never an IVO. It just didn't make sense to me that the very thin chord and thin profile of the IVO blades could out perform something thicker and fatter. After watching my friends make pitch adjustments with the IVO in about 5 minuites, I would always be a little jealous because my props would take 5 to 10 times longer to adjust. However, the biggest eye opener was performance. The IVO's would always out perform everything else period! About a month ago it came time to order a prop for my 912 powered Model 4 which I am rebuilding. I bought an IVO 70" IFA. I will post some performance numbers after I fly it.

Cain B

[Monocock]

Like Dorsal, I'm not convinced about the benefits of an IFA prop on what is quite a draggy airframe.

My Mk 5 climbs at 1700 fpm and cruises at 110 knots with a ground adjustable Kiev. For the £3000 it would cost for an IFA, how much more performance would I actually get? If it was a slippery aircraft with retractable undercarriage and a potential cruise of 150 knots I could see the benefits. My VNE is 11 knots faster than my current cruise so it just doesn't warrant the cost. Climbing at 1700 fpm doesn't bring many problems out of strips although I am aware that some climb at nearer 2000 fpm.

All in all, my a/c's performance never ceases to amaze me so my £650 Kiev is doing its job. I know I have harped on about how good they are but I really would recommend someone trys one before they go to the expense of an IFA.

[DesertFox4]

Monocock, if you're already flying at 110 knots and climbing at 1700 feet per minute why would you change?

Just FYI: the Ivo inflight ultra-light costs
$1,200. US. Works great on a 912S 100 hp and only weighs 9.5 lbs. This is the prop. I have on my model 4.
I cruise between 115 and 125 mph and top out at full throttle 132 mph. No wheel pants or radiator scoop or any other speed mods, yet.
I do think it's easier on the Rotax gearbox due to it's lower weight.

The 3 blade ground adjustable ultra-light is $600.00. Weighs 8 lbs.

[kitfox2009]

Hello Monocock
I agree, if you are already posting performance numbers like that, there is certainly NO reason to consider any other prop.
The part about props that I do not understand though is, how does ANY fixed pitch perform at the maximum when the physical specifications of the prop do not change regardless of RPM or loading. I know just a slight pitch change on my IVO IFA will make at least 200RPM tach change instantly!! A complete static cycle through from course to fine will change about 1000RPM. Surely,the ability to adjust pitch to match conditions must result in more efficiency for any propeller.

[Monocock]

Kitfox2009,

I agree, a ground adjustable prop on the whole will be no where near as efficient as an IFA one. However, there is a large variation in the efficiency of different ground adjustable props. I went from a GSC to a Kiev and I was utterly amazed at the difference. The GSC didn't run that smoothly, was noisy and performed around 20% worse in the climb and cruise. It seemed rigid and unforgiving.

I would strongly urge anybody who is considering an IFA to try a Kiev 263 before they spend their money. The smoothness is incredible and you will be amazed at the acceleration!!!!!!!!!

[Dorsal]

It is true that you can't have a fixed pitch prop optimized for both cruise and climb. In my case I have set the pitch for best cruise and therefore sacrifice takeoff and climb performance. You could also make the case that even in cruise an IFA prop could be tuned for altitude but I am not sure how much effect that would have.

[Slyfox]

i could not imagine flying with out my ifa. I love taking off and passing the cessna on the other runway. That's matching his altitude and such. I start off with flat pitch and bump the switch a little and maintain 5800 and climb out and slowly reduce rpm with prop adjustment to 5200 and pretty much pass the cessnas, a real hoot. don't go with what I can do for a max climb out it really bothers people.

[Dorsal]

That sounds like fun, given what I can do at 5200 rpm I often wonder how much fun it would be if I could actually use full power on takeoff

[jhmcglynn]

Hi All, this question may come under the heading of "it's easier to beg forgiveness than ask permission" but here goes. I guess "IFA" stands for In Flight Adjustable. Regarding LSA - is there any rules that will allow you to put an IFA on your Kitfox and stay within the LSA category?

[Slyfox]

ya, put the switch under the cowl, you can at least change it on a whim without pulling out the wrenches. You can't be flying unless your good at wing walking:eek:

[Av8r3400]

Placard the switch: "Ground Adjust Only"


Problem solved.

[jrthomas]

In response to Av8r3400, one word, "brilliant"! If we can placecard maximum cruise rpm to prevent a light sport aircraft from exceeding 138mph why not placecard an IFA prop switch "Ground adjust only". Cub Crafters pulled it off and leaves up to the pilot to limit cruise power to 80hp out of a 180hp engine. If that will flush with the FAA then Av8r's idea should be a breeze. James Thomas

[Squirrelfox]

Regarding Brilliant....Can't help responding.

Let's take the placarding a step further:

"SS7 Take off weight limited to 1320 pounds while operating as LSA; else 1550 pounds with gear upgrade"

Problem solved, opens up the options:rolleyes:

Now don't you think the FAA will cooperate?

[jrthomas]

I know it's silly. It seems at first to be a violation to put an IFA prop switch in reach of the pilot but Cub Crafters pulled off putting 180hp within the pilots reach and leaving it to the honor system that the pilot won't ever use it to exceed max cruise limits. All this in a 900lb+ airplane with a 400lb load limit that the FAA trusts the pilot not to exceed. Cub Crafters makes it all legal with placecards. My agreement with Av8r was, just for the sake of discussion. If it works for Cub Crafters, why not Kitfox? To be realistic, DAR's see things differently. Some follow the letter of the manual and some interprete. There may be some DAR's that would let it slide. Anyway, I just jumped in the conversation as "Food for thought" ,"what if". I have a Speedster With a Kiev and have no desire for a IFA prop. James Thomas

[Monocock]

Another Kiev disciple!
I know I harp on about the merits of Kiev props but everyone I have met who flys behind one agrees - what they do to an aircraft's performance is quite incredible and they are one of the cheapest out there too.

[jdmcbean]

I know it's silly. It seems at first to be a violation to put an IFA prop switch in reach of the pilot but Cub Crafters pulled off putting 180hp within the pilots reach and leaving it to the honor system that the pilot won't ever use it to exceed max cruise limits. All this in a 900lb+ airplane with a 400lb load limit that the FAA trusts the pilot not to exceed. Cub Crafters makes it all legal with placecards. James Thomas

Be careful... The speed limit on a road is 35 and if going 45 and get caught you get a ticket... If you don't get caught.. then it didn't matter. In aviation it will most likely only matter with Insurance... very rarely a ramp check (but it does happen) On the other hand we need to stop calling the prop In-Flight Adjustable and rename them to something like Electric Adjustable Pitch :) It does say ground adjust not that it has to be manual.

The rule FAR 1.1: emphasis on the first line (ORIGINAL CERTIFICATION, has CONTINUED TO MEET the following_

Light-sport aircraft means an aircraft, other than a helicopter or powered-lift that, since its original certification, has continued to meet the following:
(1) A maximum takeoff weight of not more than--
(i) 1,320 pounds (600 kilograms) for aircraft not intended for operation on water; or
(ii) 1,430 pounds (650 kilograms) for an aircraft intended for operation on water.
(2) A maximum airspeed in level flight with maximum continuous power (VH) of not more than 120 knots CAS under standard atmospheric conditions at sea level.
(3) A maximum never-exceed speed (VNE) of not more than 120 knots CAS for a glider.
(4) A maximum stalling speed or minimum steady flight speed without the use of lift-enhancing devices (VS1) of not more than 45 knots CAS at the aircraft's maximum certificated takeoff weight and most critical center of gravity.
(5) A maximum seating capacity of no more than two persons, including the pilot.
(6) A single, reciprocating engine, if powered.
(7) A fixed or ground-adjustable propeller if a powered aircraft other than a powered glider.
(8) A fixed or autofeathering propeller system if a powered glider.
(9) A fixed-pitch, semi-rigid, teetering, two-blade rotor system, if a gyroplane.
(10) A nonpressurized cabin, if equipped with a cabin.
(11) Fixed landing gear, except for an aircraft intended for operation on water or a glider.
(12) Fixed or retractable landing gear, or a hull, for an aircraft intended for operation on water.
(13) Fixed or retractable landing gear for a glider.

Regarding CubCrafters Carbon Cub with a 180hp.. I could be corrected on the speed.. but I doubt a Cub can be pushed to 120 kts even with 180 hp... The ASTM rule comes into play. This is not true on the Experimental Amatuer Built aircraft... but an S-LSA must meet a minimum useful load requirement and the formula is based on continuous HP and number of seats. So CubCrafters restricts THEIR engine RPM to continuous operation of 80hp and you can use the max hp for up to 5 minutes (Rotax 912- 5500 continuous 5800 max 5 minutes) using the formula at 80 hp the Cub must have a minimum useful of 433lbs (887 Empty) and at the 180 hp 501lbs (819 Empty)..

Now.. how about the CC340 on a Kitfox :D

[DBVZ]

Hi All, this question may come under the heading of "it's easier to beg forgiveness than ask permission" but here goes. I guess "IFA" stands for In Flight Adjustable. Regarding LSA - is there any rules that will allow you to put an IFA on your Kitfox and stay within the LSA category? The continuous requirement would mean that if an otherwise eligible LSA were to ever have an IFA prop on it, even briefly, it is permanently ineligible to be flown under Sport Pilot rules. Kind of a big decision, if you have an eligible LSA and may some day want to go Sport Pilot. Everyone gets older. It also limits resale opportunities.

[herman pahls]

I have 450 hours behind a Rotax 532 and ground adj.Ivo light prop on my model 2. Great results.
I am considering going with a 582 and called Ivo as to what C-box ratio and Ivo prop would get the best short field performance.
They suggested the 3.47 C-box and Ivo medium.
What gearbox ratios do the 912's use that they can use the ultralight Ivo's?
Has anyone used the in flight adj. Ivo's on a 532/582 and what were the results?
Thanks Herman

[N82HB]

I had a two blade IFA Ivo on a 582 with C-box. It was not ideal, but had some benefits. It is very important to take the time to set up the washers for the fine and coarse stops to make it easier to use while in flight.
Here is the part to watch out for:
With a two stroke where mixture is so important you need to learn about "effective jetting." As you go fine on the pitch your engine goes lean and then coarse makes the engine go rich, for any given RPM. It is just one more way we have found to make a 2-stroke burn up that much faster. You can make it work, but it is pretty risky and quite a bit of work to get set up right.
Kelly

[herman pahls]

Kelly
Thanks for your imput regarding in flight adj. and 2 strokes.
Sounds like a mixture control would ideally be needed.
I prefer not to use the Ivo medium prop due to added weight and cost.
What C-box ratios are being used on 582's and Ivo light props for best climb performance?
Thanks Herman

[akflyer]

I have 450 hours behind a Rotax 532 and ground adj.Ivo light prop on my model 2. Great results.


I run a 3 blade 72" IVO IFA on my 582 with 3:1 gears. I had 2.62 originally, and even though IVO says that it is not suggested, I have not had any issues running the 3:1. I have the tape over the blade roots so I can see if there is any movement and in 200 hrs, I have not cracked a tape.

I love the IFA and would not give it up for anything! Jet per the charts and you can use the IFA to keep your EGTS exactly where you want them. More pitch, EGT's go down, less pitch they go up. I also have inflight mixture control, but I think I may get rid of that as you can tweak and turn and doink with them all day instead of enjoying your flight! The only time I found them really useful is in the winter time when I take off from a river or lake bed and it is -25f or -30f and at 1000' it is 20f above. Then it is important to be able to control the mixture and riched it up down low. I never fly high enough up here to warrant the mixture control 98% of the time!

[akflyer]

The continuous requirement would mean that if an otherwise eligible LSA were to ever have an IFA prop on it, even briefly, it is permanently ineligible to be flown under Sport Pilot rules. Kind of a big decision, if you have an eligible LSA and may some day want to go Sport Pilot. Everyone gets older. It also limits resale opportunities.

No need to mention the prop on the plane... you can just put in the log book that it has an IVO ground adjust if you are worried about sport pilot. Most times you will find that it is better not offer up any info you are not directly asked when it come to dealing with the authorities.

[Av8r_Sed]

Herman,

I've got a Model III 582 with a 3:1 C gearbox. I've been advised by IVO and the factory to go with the medium 70" IVO two blade. I haven't flown this configuration yet but hope to soon.

-- Paul S

[DBVZ]

No need to mention the prop on the plane....Now we are into falsification of records if it actually has a IFA prop. Someone earlier suggested calling the IFA an "electric adjustable" prop instead of in-flight, and then the issue of ground adjust or in-flight becomes a question of where the control is located. Under cowl would make it ground adjust, and in the cabin it would be in-flight. But I asked that of an aircraft MFG rep, and he said that had been tried and rejected by the FAA. Not Kitfox, but the same FAA. If your records are accurate and complete, if it had an IFA prop on it the logs will indicate that by explicit statement or by the model number of the installed parts. And if it ever had an IFA prop it is FOREVER not Sport Pilot eligible. Stupid rule, but that is what they say. Same issue about 2 seats. The Avid Catalina is 600 empty, 1200 gross, but usually has a third seat in back. If it was ever operated as a 3-seat plane it is not eligible for Sport Pilot. But if it was not operated as a 3-seat, and the rear space is marked "baggage area, weight limit 200 pounds", my understanding is that it would be Sport Pilot legal. The "continuously maintained" part of the regulation just limits the number of legal LSA aircraft for no purpose. If it is currently configured to conform, what difference does it make that it was not a few years ago?

And my point was, if you ever think you may want to fly it as a Sport Pilot, think about that before you put an IFA prop on it or you may need to replace the plane sometime in the future. If you don't care about Sport Pilot, and don't care about the loss of some potential buyers in the future, then go for the IFA prop and be done. It should give you better control of performance. For a young healthy owner, the issue may be decades away and easy to ignore. But some of us are not that young anymore. And it may be worth thinking about this more now, and regretting less later.

[herman pahls]

AKflyer
Are you using a 72" light or medium Ivo?
Since you are on floats, would the 3.47 C-box with Medium blades give much better take-off and climb.
Thanks Herman

[napierm]

What is the total cost for the 2-bladed medium IVO?

You need the blades, the hub, and the adapter block for the R582 C gearbox flange. How much for the package?

[akflyer]

72" 3 blade light is what I am running now. I have acesse to a medium, and am thinking about doing a pull test with both props to see what the actual numbers are that I can get.