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What makes the latest models so fast?


milotron

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I realize that there is a lot more HP in the engine, but altitude aside are there that many improvements in the aerodynamics and drag reduction of the latest models to get the speed increases?  Or is it really just the brute force HP?

Looking at the Rocket models, what do they cruise at at various altitudes? That is a good example of a stock m20K vs the same airframe with a bunch more HP.

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39 minutes ago, milotron said:

I realize that there is a lot more HP in the engine, but altitude aside are there that many improvements in the aerodynamics and drag reduction of the latest models to get the speed increases?  Or is it really just the brute force HP?

Looking at the Rocket models, what do they cruise at at various altitudes? That is a good example of a stock m20K vs the same airframe with a bunch more HP.

Should be more Ovation 2 / 3 owners who can report performance. That would be thenplane to compare to the NA Ultra, M20-U. Some O owners here have done the 310hp upgrade.

My opinion as a well-read C owner is several factors are responsible for the Ultra speeds (which I think are the same as the last pre-Ultra models):

  • More hp (310 vs. 280)
  • Higher RPM
  • Aerodynamic tweaking
  • Different propellor

This should be similar to the Acclaim vs. Acclaim Ultra, too.

How much speed increase is there?

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2 hours ago, milotron said:

I realize that there is a lot more HP in the engine, but altitude aside are there that many improvements in the aerodynamics and drag reduction of the latest models to get the speed increases?  Or is it really just the brute force HP?

Looking at the Rocket models, what do they cruise at at various altitudes? That is a good example of a stock m20K vs the same airframe with a bunch more HP.

It's mostly the HP, but at the higher speeds the aerodynamic improvements kick in.

A few years ago (probably 5) I flew my M20C side-by-side with a friend who owned an Ovation3.  I did a write up back then but can't find it now.  The interesting thing about it was not the speed, which of course the O3 won, but the fuel flows.

As I recall, when we were both at 12 gal per hour, the Ovation was faster.  At 10 gph, about the same; at 8gph, my C was faster.  And then my friend threw the coals to his Ovation and left me like I was standing still!

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18 minutes ago, Andy95W said:

It's mostly the HP, but at the higher speeds the aerodynamic improvements kick in.

A few years ago (probably 5) I flew my M20C side-by-side with a friend who owned an Ovation3.  I did a write up back then but can't find it now.  The interesting thing about it was not the speed, which of course the O3 won, but the fuel flows.

As I recall, when we were both at 12 gal per hour, the Ovation was faster.  At 10 gph, about the same; at 8gph, my C was faster.  And then my friend threw the coals to his Ovation and left me like I was standing still!

This is what i had been looking at and where the consideration to Rocket speeds/performance comes in.

That is interesting comparing the fuel flows and something I had been looking at also. Assuming similar fuel flows and rich of peak ops, the Acclaim is faster than my 252 according to the book.

 

Does the long body enhance the aerodynamics and therefore speed? It seems that most of the aero improvements are in the cowl area as the rest is virtually identical to J and K models, even the small inner gear doors went away, as did the flap hinge cowls.

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Cowl and windshields are the primary improvements from the J models on. Anytime you can carry power to higher thin air your going to get better speed. Then further improvements like gap seals smooth rivets are going to squeak out a few more knots. 

17 minutes ago, Andy95W said:

It's mostly the HP, but at the higher speeds the aerodynamic improvements kick in.

A few years ago (probably 5) I flew my M20C side-by-side with a friend who owned an Ovation3.  I did a write up back then but can't find it now.  The interesting thing about it was not the speed, which of course the O3 won, but the fuel flows.

As I recall, when we were both at 12 gal per hour, the Ovation was faster.  At 10 gph, about the same; at 8gph, my C was faster.  And then my friend threw the coals to his Ovation and left me like I was standing still!

Funny, I flew about 4 hours of flight with a friends and fellow Mooneyspacer’s (stinkbug) C in my Eagle and we were only a couple gallons apart from each other when we filled up. I was flying very LOP to stay at the same speed. We didn’t plan it and it was more of an observation since we both had a good idea of our fuel levels when we started.

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1 hour ago, bradp said:

Apparently the new ovation had some improvements done to the cowling and cowl flap designs to add a couple of knots.  

All the ovations and acclaims dont have cowl flaps. I believe on the ultra models, they come with the faster thinner blade. Cruise speeds should be around the 185 to 190 knots which is 2 to 4 knots faster than the eagle I fly, but the eagle i fly has the fat 3 blade hartzell. At 18 gallons per hour I can get 192 to 194 knots. I prefer 16 gph at 180 knots. You can also run the ovations pretty high powered since the cylinders stay really really cold. Like mine range from 280 to 310 degrees at 10k ft, flying rich of peak.

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Should be more Ovation 2 / 3 owners who can report performance. That would be thenplane to compare to the NA Ultra, M20-U. Some O owners here have done the 310hp upgrade.
My opinion as a well-read C owner is several factors are responsible for the Ultra speeds (which I think are the same as the last pre-Ultra models):
  • More hp (310 vs. 280)
  • Higher RPM
  • Aerodynamic tweaking
  • Different propellor
This should be similar to the Acclaim vs. Acclaim Ultra, too.
How much speed increase is there?


In cruise remember you’re not using any of the extra 30hp of the 310hp ovations. That’s reserved for takeoff and climb. I have a 280hp ovation with the new prop. It’s an O1. The 310 hp upgrade wouldn’t make me any faster...


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25 minutes ago, gsengle said:

In cruise remember you’re not using any of the extra 30hp of the 310hp ovations. That’s reserved for takeoff and climb. I have a 280hp ovation with the new prop. It’s an O1. The 310 hp upgrade wouldn’t make me any faster...

 

The extra power will let you cruise higher, which is generally faster due to less drag in the thinner air. Power falls off as altitude increases, so starting with more power, you can retain the same % power up higher. 

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The extra power will let you cruise higher, which is generally faster due to less drag in the thinner air. Power falls off as altitude increases, so starting with more power, you can retain the same % power up higher. 


Um that’s not how it works... same displacement. Same service ceiling. All ya have is higher rpm available. Which you don’t use in cruise. No turbo. I cruise up high at 2300rpm not 2700.


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7 hours ago, Andy95W said:

It's mostly the HP, but at the higher speeds the aerodynamic improvements kick in.

A few years ago (probably 5) I flew my M20C side-by-side with a friend who owned an Ovation3.  I did a write up back then but can't find it now.  The interesting thing about it was not the speed, which of course the O3 won, but the fuel flows.

As I recall, when we were both at 12 gal per hour, the Ovation was faster.  At 10 gph, about the same; at 8gph, my C was faster.  And then my friend threw the coals to his Ovation and left me like I was standing still!

that's interesting about the speeds at certain gph.  I figured the newer cowlings were a little slicker, but I figured it was HP shoving it through the atmosphere.  

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I’ve had a 1977 J then. 1988 J, purchased new, I purchased 2005 BravoGX in 2006.

The two J’s basically the same except the 88 was 5-7 knots faster, assumption is they cleaned up the frame a little over the years.

The Bravo being heavier and larger depends on brute power to mover it along obviously the higher the faster. Keeping these things in rig and mechanically perfect provides for the best speed over efficiency, of which the Bravo is limited by higher fuel usage.

I assume the Bravo, eagle and Ovation have similar speeds below 10,000 feet then the changes in atmospheric conditions kick in.

The speed we gain are through a multitude of items, airframe, power and more important  the atmosphere.

The great thing about our Mooneys is the wide range of utility, from awesome C model providing 140-150 knots on well less than 10gph through the  mighty U models providing up to 242 knots on 20 GPH

There have been a lot of discussion on this site, I thought it was a Mooney site discussing the attributes of Beech models, that’s another topic I’d like to stay away from.

Look at our vintage birds through our latest models, there’s quite a difference in there utility,speed efficiency and useful load. Not much of a reason to stray away.

GO MOONEY

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26 minutes ago, Danb said:

Look at our vintage birds through our latest models, there’s quite a difference in there utility,speed efficiency and useful load. Not much of a reason to stray away.

GO MOONEY

Dan, I love Mooney's, but respectfully disagree with your last comment.  The useful load on Mooney's isn't that great.  I'd call it average at best.  The reported numbers from owners shows a sample that ranges from 850-1050 for all models.  There were some outliers though that had a few more (or less) pounds available.  I would not put load carrying into the strong attribute category for any Mooney.  

Anyone know why every model has the same baggage compartment weight limit - 120 pounds?  Did Mooney just take a shortcut to keep the certification the same across the models instead of doing the testing to increase it?   The Ovations and Acclaims have huge amounts of space behind the rear passenger seats, but they aren't dragging three folding bikes (22 pounds each) and clothes for three people on a long weekend due to that weight restriction back there.  I'd still be in a Mooney if I could have found anything that was close to 1200# useful.  What you carry is one of the three pillars - you can get two, but getting all three (speed, efficiency, & load) ain't happening in the piston world we live in.

Cheers,

Brian

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Dan, I love Mooney's, but respectfully disagree with your last comment.  The useful load on Mooney's isn't that great.  I'd call it average at best.  The reported numbers from owners shows a sample that ranges from 850-1050 for all models.  There were some outliers though that had a few more (or less) pounds available.  I would not put load carrying into the strong attribute category for any Mooney.  
Anyone know why every model has the same baggage compartment weight limit - 120 pounds?  Did Mooney just take a shortcut to keep the certification the same across the models instead of doing the testing to increase it?   The Ovations and Acclaims have huge amounts of space behind the rear passenger seats, but they aren't dragging three folding bikes (22 pounds each) and clothes for three people on a long weekend due to that weight restriction back there.  I'd still be in a Mooney if I could have found anything that was close to 1200# useful.  What you carry is one of the three pillars - you can get two, but getting all three (speed, efficiency, & load) ain't happening in the piston world we live in.
Cheers,
Brian


Hey aren’t you on the shunned list with Guitarmaster and a few other traitors?


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My J has 940 useful. Full fuel is ~7 hours running lop.  With 1/2 fuel (enough for a 350 nm trip with 1 hour reserve) I can legally carry 4 170 pounders and 68 pounds of baggage.  That has always been sufficient for me. There is no good reason to carry enough fuel for 800 miles if you aren't going to need it.  

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From a practical point of view, aerodynamics, or more accurately, drag reduction is how speed is achieved. Whether that drag reduction is a function of altitude, engine cooling drag, lift related induced drag, parasitic drag such as fuselage shape/frontal area or antenna/accessories drag. It all matters. The fastest designs address optimize all. The Lancair with IO550 can cruise at 275Kts due to very small frontal area, low cooling drag, a sleek fuselage and minimized external drag inducing antenna and a sleek, small wing. 

Adding HP and it's related fuel burn is not likely to be the ideal way to achieve a given speed. The exception is adding HP at altitude. 

The interesting thing that happens with normally aspirated engines is that altitude related HP loss (lapse rate) is, within limits, matched by the reduced drag up high. With many normally aspirated aircraft, the cruise speeds possible at low altitudes are not all that far off from the speeds possible at higher altitudes. 

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My J has 940 useful. Full fuel is ~7 hours running lop.  With 1/2 fuel (enough for a 350 nm trip with 1 hour reserve) I can legally carry 4 170 pounders and 68 pounds of baggage.  That has always been sufficient for me. There is no good reason to carry enough fuel for 800 miles if you aren't going to need it.  

My 78 is a few pounds short of a 1000, you give me a later model with 160lb increase, and 100 AMUs, I can get you close to 1200.

As delivered I had 996, at the time I bought it, 938.

 

Tom

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4 hours ago, rbridges said:

that's interesting about the speeds at certain gph.  I figured the newer cowlings were a little slicker, but I figured it was HP shoving it through the atmosphere.  

They make a huge differenc because of the equation that drag increases to the square of the speed.  A little more speed = a lot more drag.  For my C to go the same top speed of the Ovation would take a lot more than 280 HP.

(Your C is different- you've got the fancy cowling I want on mine.)

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3 hours ago, flight2000 said:

Anyone know why every model has the same baggage compartment weight limit - 120 pounds?  Did Mooney just take a shortcut to keep the certification the same across the models instead of doing the testing to increase it?

I mentioned this in another thread, but I think it's a structural limitation for the floor.  In the construction manual for the RV-10, for example, they make a specific point in dictating the maximum allowed weight in the baggage area is 150 lbs, and this is obviously before any individual RV-10 is balanced and weighed.  I suspect all Mooney's have identical construction of the baggage area rearwards

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As cujet mentioned it’s kinda a trade off a Lancair with 300+hp Will barrel through the sky approaching 300 knots. Brian mentioned useful load it’s all dependent on the mission, mine is fulfilled with the long body, I don’t plan on going on Beech talk, Cirrus world or other sites to outline the virtues of Mooney’s nor the other sites. It rankles me to no end other types of ships coming onto our sight outlining the excellence of there planes, even when true.Theres no doubt every plane has shortcomings and qualities, if they meet your need and mission they’ve accomplished their intended goal.

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