Prop Pitched Today... CTLSi

[AGLyme]

Gang, hopefully this helps someone...

Flew to Woodstock this AM and met up with Arian. Wind was calm, in fact when I arrived at Woodstock a Balloon had just landed and they were folding up. I didn't have much time today, so Arian performed only one pitch adjustment setting.

First Setting:  At Arian's suggestion, DECREASED pitch by 1/2 degree to 27.5 degrees, 16" from blade tips.

Metrics On the trip to Woodstock, CT, "old pitch setting" altitude: 2,000', OATemp: 65 degs F, all speeds are in"Knots",  Wind was "VAR", no Xwind Component both ways

Throttle %: 95%, RPM's: 5090, Tape: 102, TAS: 107, GS: 105, Fuel Burn/gal per hour: 4.5

Throttle %: 97%, RPM's: 5220, Tape: 107, TAS: 111, GS: 110, Fuel Burn/gal per hour: 4.8

Throttle %: 100%, RPM's: 5490, Tape: 112, TAS: 117, GS: 115, Fuel Burn/gal per hour: 7.0

Metrics On the trip Back To Chester, CT, after Pitch adjustment , altitude: 2,000', OATemp: 65 degs F, all speeds are in"Knots".

Throttle %: 95%, RPM's: 5270, Tape: 106, TAS: 110, GS: 109, Fuel Burn/gal per hour: 4.7

Throttle %: 97%, RPM's: 5360, Tape: 108, TAS: 113, GS: 110, Fuel Burn/gal per hour: 4.9

Throttle %: 100%, RPM's: 5650, Tape: 114, TAS: 118, GS: 117, Fuel Burn/gal per hour: 7.1

 VARIANCES:

@ 95% Throttle:  +180 RPM's,  Tape: +4, TAS: +3,  GS: +4, Fuel Burn:  +.2, (burns more fuel, has higher RPM's result)

@97% Throttle:  + 140 RPM's,  Tape: +1, TAS: +2,  GS: +-0, Fuel Burn:  +.1, (burns more fuel, has higher RPM's result)

@100% Throttle:  + 160 RPM's,  Tape: +2, TAS: +1,  GS: +2, Fuel Burn:  +.1, (burns more fuel, has higher RPM's result)

Observations; I have never seen such high RPM's in 160hours of flying the plane.  I am trying to wrap my head around the "decrease" in pitch by 1/2 degree, increased RPM's (makes sense), resulting in increased speed?  I don't get it, but I'm sure a lot on the forum do.

Happiest about the 95% Throttle setting.  I usually travel in the 92-94% range to get the gals/per hour under 4. 

If the "Tundra" tire setup decreases speeds by 3 knots than the stock tires, then I am in range of other LS's I think... A good exercise.

PS:  Prior to re-pitching... each prop had a different pitch setting, I don't recall the values, they weren't dramatic, but, probably a good idea to check the pitch settings at every annual.  Would appreciate others' thoughts on this point.

 

[GlennM]

I like the original setting;  that is how my CTSW is set up. You can't cruise around at 5650rpm, but others will disagee.

[Ed Cesnalis]

1 hour ago, AGLyme said:

I am trying to wrap my head around the "decrease" in pitch by 1/2 degree, increased RPM's (makes sense), resulting in increased speed? 

There is no 98hp produced unless you are at 5,800 with a wide open throttle.  There is no 92hp unless you are at 5,500 with a WOT. Flattening the pitch lessens resistance and allows the motor to spool up to higher RPM where it produces more power. Using more power results in more speed.

[GlennM]

I don't know. You can only go over 5500 rpm for 5 minutes.  That is why I am at 5500 rpm and full throttle. I would rather be at full throttle for longer than 5 minutes.

[GlennM]

If only someone invented a propeller that could be at a fine pitch to take off and a coarse pitch for cruise!  They would be a Millionaire!

[Duane Jefts]

35 minutes ago, GlennM said:

I don't know. You can only go over 5500 rpm for 5 minutes.  That is why I am at 5500 rpm and full throttle. I would rather be at full throttle for longer than 5 minutes.

Glenn, you don’t have altitude issues in Fla but if you fly west and fly out of some of the high altitude/low density airports, you need the extra power available afforded by the higher rpm settings. I have seen folks “skimming” the tree tops out of Bryce Canyon trying to get altitude while The CTL I was in easily climbed out. My rpm at max throttle is 5600.

[Ed Cesnalis]

My new to me CTSW was pitched by the last owner.  5,500 @ WOT happens around 10,000' and produces 130kts.  At 12,500 I'm back down to 125kts @ WOT (works for me) I can cruise around the coast indicating up to 130knots.

My new field elevation is 51'.  Solo I keep my climb down under 1,500fpm so I can see.  Two of us and 20gal got 1,300fpm.

I attribute most of top performance to the Sensenich prop.

[AGLyme]

Thx Ed for clearing up the gap in my thinking re RPM, speed and horse power... makes sense.

Good to have you back.  I think it’s going to be tough to match those superb mountain pics you used to take.  

[Ed Cesnalis]

1 hour ago, AGLyme said:

Thx Ed for clearing up the gap in my thinking re RPM, speed and horse power... makes sense.

Good to have you back.  I think it’s going to be tough to match those superb mountain pics you used to take.  

Thanks for the kind words.  The Oregon coast and nearby cascades provide plenty of opportunity.  I've shot on the ground with my cell phone a little and I'm ready to take my real cameras up in the CT.

[GlennM]

6 hours ago, Duane Jefts said:

Glenn, you don’t have altitude issues in Fla but if you fly west and fly out of some of the high altitude/low density airports, you need the extra power available afforded by the higher rpm settings. I have seen folks “skimming” the tree tops out of Bryce Canyon trying to get altitude while The CTL I was in easily climbed out. My rpm at max throttle is 5600.

I can understand that. It just comes down to what is best for you and how you operate.

[FlyingMonkey]

15 hours ago, Ed Cesnalis said:

My new to me CTSW was pitched by the last owner.  5,500 @ WOT happens around 10,000' and produces 130kts.  At 12,500 I'm back down to 125kts @ WOT (works for me) I can cruise around the coast indicating up to 130knots.

My new field elevation is 51'.  Solo I keep my climb down under 1,500fpm so I can see.  Two of us and 20gal got 1,300fpm.

I attribute most of top performance to the Sensenich prop.

You really think the Sensenich is that good an upgrade?  I keep thinking I might replace my Neuform, but then not pulling the trigger because I'm not sure what it would buy me.  I'm also a little leery of losing another inch of prop clearance, in that I do 50% of my landings on grass.

[Ed Cesnalis]

For me the upgrade is from Warp Drive to Sensenich.  In my case I do.

[Roger Lee]

Warp Drive to Sensenich was well worth it especially in climb. The difference between Sensenich and Neuform isn't very much and they are pretty close. Remember to set the prop pitch for flying at your average altitude. Don't set it for 1K AGL in your area if you always seem to fly at 8K AGL.. If you have special needs for a better climb prop then flatten the pitch a tad to get better climb knowing that you will lose a bit of top cruise speed and fuel. The 5600 - 5650 rpm at WOT at your average altitude is the BEST BALANCED setting for the average person. 

It's all about our individual flying needs.

[AGLyme]

Makes sense Roger.  Connecticut is close to both the sea and hills (not of the Ed variety).  On cross countries I plan for 4,500.  On local flights, 2,500 - 3,500.  
I am going to perform some takeoffs soon to determine if the climb out has improved with the lift in RPMs.  I hope it’s noticeably improved.  I could have used the 4 knots improved speeds on my epic 1,800 miles flight a few weeks ago...

[FlyingMonkey]

I always try to bias performance for climb instead of speed.  Nobody ever got killed by having too much climb.  The opposite is not true.

[Ed Cesnalis]

The classic trade off has always been seen as cruise vs climb.  A climb prop or a cruise prop.  Rotax complicates things with 5,500 continuous limitation and a 5,800 5 minute limitation.

Its not true, the trade off is Speed/Climb vs Economy.  As a community we choose performance over economy but tweak between best climb (5,800) and best cruise (5,500) @ WOT .  The 5,600 recommendation splits the difference.  I still advocate the 5,500 @ WOT setting because it allows best speed where 5,600 in general limits best speed.

Economy settings are nice but not so practical with a ground adjustable prop.

[Roger Lee]

Fly WOT at 5600 then. Won't hurt a thing, but you'll burn extra fuel for little speed gain. Same for the WOT at 5500 all the time. The speed gain isn't worth the extra fuel. Once over 5300 then fuel burn goes up faster than speed. So you have to decide if paying extra money on fuel is worth saving a few minutes in time.

[cdarza]

Ive also experienced that my 2006 CTSW has a slightly quieter cruising @5000rpm.   When I throttle up to 5200 or higher there is a small but noticeable change thus 5000 is my sweet spot.  I just wish I had the speeds some of you get.  100kts to 105 is my typical indicated.   Although, am never in a hurry to get anywhere so i'll live with that  Oh and I've got the Sensenich.  I don't have comparison to the old Neuform had but am happy with it. I replaced my Neuform as there were alot of tiny cracks developing - probably paint issue only but  for my personal logistics and cost to get sent to Neuform to check it and back to me was close to same cost as buying new prop. 

[cdarza]

Yikes - I just took a look at the prop which has been wall decor.    The cracks were nothing like that when I removed the prop years ago. 

[Warmi]

1 hour ago, cdarza said:

Yikes - I just took a look at the prop which has been wall decor.    The cracks were nothing like that when I removed the prop years ago. 

Whoa .. what sort of indoor environment you got there to exact this sort of punishment on your wall decor prop ?

[cdarza]

1 hour ago, Warmi said:

Whoa .. what sort of indoor environment you got there to exact this sort of punishment on your wall decor prop ?

Was thinking the same. LOL   Hot,humid weather but daily night time airconditioner --- I dunno ??

 

[Roger Lee]

I've seen two other Neuform props with cracks like this and both were from sun damage. Many years ago Neuform told us their props weren't meant to be left outside. 

[Mike Koerner]

Roger... or anyone,

Did you ever compare the 2-blade (red) neuform with later models or the Sensenich?

Mike Koerner

[Roger Lee]

Yes, I ran 14 different props. 2 blades, 3 blades, long vs short, stiff vs flexible. I did run with the red Neuform 2 blade vs their 3 blade. I used 4 (mfg'ed withing 3 months of each other) identical CTSW's. We all took off side by side in pairs and flew within 50' - 100' of each other in the air.As many variables as possible was taken out or controlled. To my knowledge the only study of it's kind in the US.

[Bill3558]

Ag, do you know what rpms you were turning at static full power run up?   I’m turning 5200.  I think I’m about 200 over where I should be.