Power settings and performance for rocket (Not cruise)

[wombat]

I've been consistently cruising at 31/2300 and ~20 GPH from between 10,000 and 18,000 MSL

[Austintatious]

On 8/31/2023 at 7:43 AM, wombat said:

No hubcaps, but yes to under-wing fairing.

I went and flew and it took about 22-24 / 22 to hold 105 KIAS with gear down flaps up.

[Austintatious]

On 8/31/2023 at 8:54 AM, Fly Boomer said:

How would I know if I had the "under wing fairings for the main gear"?  Got a picture?  Mine was a 252 before Rocket.  BTW, these are great numbers you guys are providing.

If you have a 252, IIRC,  you have inner and outer gear doors which completely enclose the main gear, you lucky dog!  I am not sure if you would even have the under wing fairings... but If you did, you would see them on the underside of the wing right behind the gear well.

Nonetheless, Id love to see your numbers and hear more about how your airplane is configured... Do you have a blade style nav antenna?  Do you have the step still installed?  any go fast mods?

I swear I can hear the rumbling turbulence in my gear wells... It HAS to be costing me speed... I now have a new set of fairings I am going to take molds off of and make some CF replacements for both of our aircraft.  I will then be selling the original Mooney fairings

Edited September 4, 2023 by Austintatious

[wombat]

2 minutes ago, Austintatious said:

I went and flew and it took about 22-24 / 22 to hold 105 KIAS with gear down flaps up.

Your plane the came config as mine with the fairings and no hubcaps?

[Austintatious]

4 minutes ago, wombat said:

Your plane the came config as mine with the fairings and no hubcaps?

 no hubcaps, no wing fairings.  I do have a blade style Nav antenna.   Ohh and IIRC I think I actually was around 100 kias not 105... Sorry, I did a weekend offshore fishing trip since I did it and I am going off memory here...  But it doesn't sound like you are that far off really.  How sure are you that your MP readings are correct?

Edited September 4, 2023 by Austintatious

[wombat]

1 hour ago, Austintatious said:

How sure are you that your MP readings are correct?

Based on the other readings I get from my engine monitor like fuel level and % power......  Not at all sure.    

I might be able to fly 24" and 100 KT with the gear down.   

[Fly Boomer]

1 hour ago, Austintatious said:

If you have a 252, IIRC,  you have inner and outer gear doors which completely enclose the main gear, you lucky dog!  I am not sure if you would even have the under wing fairings... but If you did, you would see them on the underside of the wing right behind the gear well.

Nonetheless, Id love to see your numbers and hear more about how your airplane is configured... Do you have a blade style nav antenna?  Do you have the step still installed?  any go fast mods?

I swear I can hear the rumbling turbulence in my gear wells... It HAS to be costing me speed... I now have a new set of fairings I am going to take molds off of and make some CF replacements for both of our aircraft.  I will then be selling the original Mooney fairings

Each main has three doors.  I guess they would be "upper", "lower", and "inner".  What I'm calling the "inner" door stays closed except during extension or retraction.  Sounds complex, but fortunately they seem to be rigged well -- I got to see them in action recently during my first annual (from hell).  No NAV antennae(?) on the vertical stab at all -- those are inside the wingtip.  Step is gone, so I carry a folding step I can throw into baggage before departure, and deploy before stepping off the wing on arrival.  I'm pretty tall, so I could get by without the step, but not everyone can.  I think the best "go fast" mod is the TSIO-520 -- not sure those other things matter that much.

I suspect you are right about the turbulence.  Almost anything that disturbs the airflow enough so you can hear it creates drag.

[Austintatious]

5 hours ago, Fly Boomer said:

Each main has three doors.  I guess they would be "upper", "lower", and "inner".  What I'm calling the "inner" door stays closed except during extension or retraction.  Sounds complex, but fortunately they seem to be rigged well -- I got to see them in action recently during my first annual (from hell).  No NAV antennae(?) on the vertical stab at all -- those are inside the wingtip.  Step is gone, so I carry a folding step I can throw into baggage before departure, and deploy before stepping off the wing on arrival.  I'm pretty tall, so I could get by without the step, but not everyone can.  I think the best "go fast" mod is the TSIO-520 -- not sure those other things matter that much.

I suspect you are right about the turbulence.  Almost anything that disturbs the airflow enough so you can hear it creates drag.

Wow, sounds slick!!!   can you post more speeds and power settings?    I need a goal I can never achieve to keep me insane and broke!

[Fly Boomer]

7 hours ago, Austintatious said:

Wow, sounds slick!!!   can you post more speeds and power settings?    I need a goal I can never achieve to keep me insane and broke!

I will, but first I have to get past the (first) annual from hell.  Engine mount needs work. 

[kortopates]

12 hours ago, Fly Boomer said:

Each main has three doors.  I guess they would be "upper", "lower", and "inner".  What I'm calling the "inner" door stays closed except during extension or retraction.  Sounds complex, but fortunately they seem to be rigged well -- I got to see them in action recently during my first annual (from hell).  No NAV antennae(?) on the vertical stab at all -- those are inside the wingtip.  Step is gone, so I carry a folding step I can throw into baggage before departure, and deploy before stepping off the wing on arrival.  I'm pretty tall, so I could get by without the step, but not everyone can.  I think the best "go fast" mod is the TSIO-520 -- not sure those other things matter that much.

I suspect you are right about the turbulence.  Almost anything that disturbs the airflow enough so you can hear it creates drag.

For what its worth, you can easily add the step back on, whether it was removed or never installed. The fuselage is made to bolt it on. With the step and its fairing it not a significant point of drag, If you ever deplane onto a patch of ice and fall on your butt you'll really miss it. 

[Fly Boomer]

12 minutes ago, kortopates said:

For what its worth, you can easily add the step back on, whether it was removed or never installed. The fuselage is made to bolt it on. With the step and its fairing it not a significant point of drag, If you ever deplane onto a patch of ice and fall on your butt you'll really miss it. 

Yep, I already miss it.  In my case, it was removed to get that extra 0.02 knots by a previous owner.  It is not a guarantee against falling, but it sure helps.  The step will return, but first I need to get past the annual from hell.

[Austintatious]

2 hours ago, Fly Boomer said:

Yep, I already miss it.  In my case, it was removed to get that extra 0.02 knots by a previous owner.  It is not a guarantee against falling, but it sure helps.  The step will return, but first I need to get past the annual from hell.

We have the step on one of our planes....  TBH I prefer no step... but I do use the step on the one that has it...  I feel like that dinky little thing is going to cause a nasty spill one day or break off and make me break an ankle.

[JoshK]

I've been consistently cruising at 31/2300 and ~20 GPH from between 10,000 and 18,000 MSL

Definitely ROP, which works but you could save fuel.

This was 13,5 yesterday cruising along NC and VA




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[Austintatious]

1 hour ago, JoshK said:

Definitely ROP, which works but you could save fuel.

This was 13,5 yesterday cruising along NC and VA




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I like it... Gonna have to try that... What IAS are you seeing with that?

[JoshK]

I like it... Gonna have to try that... What IAS are you seeing with that?

175/6@ 13,5
172/3 @ 11,5

ETA:
Sorry, that was TAS. 150 IAS




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[FloridaMan]

On 8/31/2023 at 8:28 AM, Austintatious said:

Some good info here and I see similar numbers but I more typically climb at 130 KIAS and try to stay at 380 CHT or less.

I am confused about the bold however.  I don't think the higher TIT at higher altitudes is because of the increased IAT but rather because the wastegate progressively closes sending more and more exhaust gas to the turbine side of the turbocharger.   

As I understand it, the IAT indication  is  a remnant from before the rocket mod.  The temp is taken before the inter-coolers (which did not exist prior to rocket mod) and is a useless indication because of the inter-coolers.

It’s the CDT that’s the remnant and I have to watch my EDM900 flash warnings in aggressive climbs on it. Additional things to note. The NB variant, according to the engine manual, can run 100% power continuous, which I do in the climb. At around FL180 I need to use the low boost pump to maintain FF in the climb and I turn it off when level. The Rocket manual says to climb at 1450 TIT at 100% and I think I figured out why. I had always thought it was a safety thing because our planes came with a single probe CHT sensor and runaway could happen quickly at high power settings. In playing with fuel flow, there seems to be a correlation with IAT and CHTs, and higher TIT seems to transfer heat to the intake side as well. Making the mixture extra rich seems to affect CHTs as much as cowl flaps.