IVO vs. Warp Drive

[mtgsxr]

Ok sorry to beat this subject up but.... I have a KF4 with 80hp 912 with a 3-blade Warp Drive. I will have to say the prop is tough ! mowed a lot of grass, weeds, cactus.. ect . But I am questioning weather I would notice a huge difference with a different prop ? Thanks.

[DesertFox4]

Russ-
What speeds and climb rates are you getting now and at what rpm's?
The Warp prop is a pretty good match for that engine. I've lots of time on a 912 with an Ivo but zero with a Warp.

[SkySteve]

mtgsxr,
Is your Warp Drive square tip or Tapered Tip? I fly behind a WD Square too with the same engine and agree, it is one tough prop. However, I would like to get more RPM's out of it for better performance. I've talked with Warp Drive and they suggest I have them taper the tips, which I am planning on doing this winter.

[mtgsxr]

It is the square tipped one with nickel leading edge.. It may have too much pitch as the max rpm I can get in level flight is 5200 rpm. typical take off is 5000 rpm. climb is 7-800 at gross at 4000ft. I was going to reduce the pitch & try but didn't want to waste my time if there was a better prop to start with.

[Timberwolf]

Let me start by saying I don't have a KF, but I do have a warp on a lycoming. I wanted more speed and didn't want to lose climb. I spoke with Daryl and sent my prop in. 3 weeks later it came back with nickel leading edges and the tapered trailing edge. I set it up at 11* and got 2350 static. Went flying and picked up an honest 15-18mph indicated. That's a huge increase being able to go from 80 mph to 95mph for the same amount of fuel and not lose any T/O or climb. Mine is a 4 blade 68" and I couldn't be happier with it. I can still take off at gross in 200 ft and land in the same distance. The only thing I lost was my immense speed brake when pulled back to 400rpm idle. It is still there, just not to the extent that it wants to drop out of the sky immediately. For $60/blade to taper, what do you really have to lose?

[kitfox2009]

MTGSXR
I run a 912UL (80HP)with a 70" IVO Ultralight IFA prop on a Vixen. My a/c is registered as a "homebuilt" at 1400 lb gross. The IFA feature seems to make the world of difference on these small gear driven engines by allowing the engine to run at maximum hp/RPM of 5800 initially and then dial in a bit of pitch to maintain 5500 on climbout.
I believe 5000 on climbout is too low (hard on the engine/redrive) and very low on power/torque.
I would think adjusting your prop for 5800 max on TO would be a better choice for engine life. I think the other recommendation of pitching for 5500 straight and level full throttle is good as well.Probably either way would come up with a similar result.
Good luck with it.
Don

[foxy]

Don is right

reduce the pitch to have 5500-5600 rpm full throttle level flight at your usual flying altitude.

some info here

http://legacy.rotaxowner.com/si_tb_i...sl-912-016.pdf

this pitch will give you the best 'average' performance, but you will only get the maximum from your engine with an in-flight ajustable.

The IVO IFA does a good job for that.

[mtgsxr]

Thanks for all the info guys ! so it looks like I should pull about 1* of pitch out & try that. maybe a IFA after I get my skis.. poor boy here.. one thing at a time

[av8rps]

You might want to visit this older thread where we were discussing ivo props. (See http://www.teamkitfox.com/Forums/showthread.php?t=2835 )

There l posted the results I was getting with my 912ul model 4 amphib with the ivo ifa. It should give you a good idea what rpms work best, and ifa vs ground adjust info based on actual in-flight operations.

Now, with all that said I need to say this: As much as I love my ivo ifa on floats, I'm not so sure we really need the ifa for our lightweight high performance Kitfoxes when theyre on wheels? Especially if they are using a 100 hp 912s rather than the 80 hp 912ul.

I primarily chose an ivo ifa because it gave me an instant 5800 rpm on my initial water takeoff run. That helps significantly to get the airplane on the step quicker (aka: planing on top the water), especially when hot and heavy. But that generally isnt needed for land based operations. The hydrodynamic drag of the water is significantly more than anyone will ever experience on wheels.

Paul

Ok sorry to beat this subject up but.... I have a KF4 with 80hp 912 with a 3-blade Warp Drive. I will have to say the prop is tough ! mowed a lot of grass, weeds, cactus.. ect . But I am questioning weather I would notice a huge difference with a different prop ? Thanks.