IVO Light vs Med - Kitfox Speedster

[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.