Best CG

[Bret]

I have been trying different CG locations when flying at different mass with ballast in baggage area. For my plane I have found that 97.2 thru 97.8 seems to have the best pitch response and pressure on the control surfaces. Anyone have any input on this matter? I also would like some input on power flow exhaust and hartzell composite 2 blade prop. Are these items worth the money for the performance gains?

[Gasser]

Sitting here on vacation contemplating the same thing on the powerflow and prop options. From what I've read in multiple sources, the composite prop offers the same performance as the 3 blade MT prop and is the biggest diameter of the three options.
The metal two blade hartsell prop offers a similar climb as the other two but is quoted as having 1-2 kts better cruse speed then the other two.

For me, the two blade metal hartsell is the best choice as you get the same climb, faster cruse and also a smoother shutdown from what I've read because the mass/ inertia of the blade is higher and it's the cheapest to boot.

The upside of the composite is it looks killer.

[CFIDave]

Not sure if this has been posted before, but the attached PDF is Diamond's comparison of the DA40 propellers.

[Gasser]

Yes, that's the article I was referring to. However I've also read several posts from the extensive Hartsell thread that is suggesting very good performance from the composite prop as well.

I think in the end it's gonna be a personal choice based on several factors. Hard to beat the durability of metal though. Lucky for me, I've got a little more time before I have to decide

[Antoine]

I have been asking lots of questions and got accurate answers from fellow forum members. Despite Diamond's statements in the pdf attached , there is reliable data from 2 sources showing the 76" Hartzell is definitely 2+ knots faster than the MT, maybe as much as 4 knots.

Test flights made by Jean (Metal prop no pf) and myself in very similar conditions lead me to believe that the Hartzell metal prop is also worth the same gain

I personally prefer the look of my MT 3 blade prop with the new "long nose" spinner, but that's a matter of taste.

And then there's noise. 5 dB more is a lot...

[Joey]

I also like the look of the MT 3-bladed prop, but the rocks did me in. We switched to the metal Hartzell and put up with the slight increase in cruise performance (2 kts). I have not really noticed a change in the climb performance. It is slightly louder but that's not a deal breaker. I have noticed it runs at 1000 rpm idle much more smoother than the MT did. I have not seen any differences on shut down between the two. We took out the ballast when we switched to the metal hartzell so the weight difference before and after was negligible. No maintenance issues yet with 120 hours on the metal hartzell.

I do have a spinner, hub and three blades (one damaged) that are for sale. They would make a good ceiling fan .

[Antoine]

Joey did you get a quote for overhauling your MT?
I think you are right: the market value in its current condition is approximately that of a ceiling fan less motor. And that's assuming the buyer does not need it packaged an shipped.
Since mine is due for overhaul too, I am in the same situation and was trying to figure out how to make the MT pay for a few inches of the Hartzell if I switched?

Any ideas?

[Gasser]

I have been asking lots of questions and got accurate answers from fellow forum members. Despite Diamond's statements in the pdf attached , there is reliable data from 2 sources showing the 76" Hartzell is definitely 2+ knots faster than the MT, maybe as much as 4 knots.

Test flights made by Jean (Metal prop no pf) and myself in very similar conditions lead me to believe that the Hartzell metal prop is also worth the same gain

I personally prefer the look of my MT 3 blade prop with the new "long nose" spinner, but that's a matter of taste.

And then there's noise. 5 dB more is a lot...

Are you of the opinion then that the two Hartzell props are the same performance? If someone was to upgrade their prop to buy the PF exhaust, why spend the extra 4-5 grand for the plastic over the metal? Other than the better looks of the composite, why pay more? You have to add the weight you saved back.
Only big reason I'd spend it would be if I wanted to replace the dead ballast with the upcoming supercharger. Then I'd break close to even post charger with the composite prop.

[Antoine]

Are you of the opinion then that the two Hartzell props are the same performance?

My opinion is not very relevant here Jeff, as I have no first hand experience and it seems that factual data is consistently proving the theory wrong. Everything is say here is somebody else's statements:

People who have upgraded from the MT prop to either Hartzell prop say the metal prop is definitely worth 2 KTAS, and that is consistent with every "official" statement from Diamond or Hartzell. Even MT admit it.
The confusing situation is that of the 76" composite pro. According to ... Hartzell it should bring no gain at all apart from the ... cool looks. But Premier Aircraft (Jeff Owen please chime in) firnly believe that this baby will get us several extra knots.
And fellow forum members have reported to me 2 to 4 knots of gain.
Go figure...

[Graham]

I have both PF and the composite on my 2010 DA40. The biggest reason I went with the composite is repair time where it can be fixed relatively quickly in N. America and doesn't require as much down time as the MT. The CofG was the disappointing part where I thought I would see a useful load gain and had extra ballast added for the lighter prop. Overall I see speeds around 4 kts higher than the book numbers. Another interesting difference was the sink rate of the plane was higher on landing with this prop (possibly due to the bigger surface area) needing a little power into the flare.

Also one final note. I had the prop with a hartzell governor and had ongoing issues with a slight stuttering sensation while in cruise flight every 15 min or so. Eventually we put on a MT governor with the prop and it has been rock solid the last 150 hrs. Hartzell is still trying to understand why this was occurring because not every plane reported it but enough did to start investigating. I haven't had an update in a while to see where things are at on a solution.