M20J 201 Model Speeds

[EricJ]

8 hours ago, ArtVandelay said:

I would assume the G5 can be recalibrated and adjusted, no?

Not airspeed.  There's a cal procedure for altitude, but not for airspeed.

[FlyingDude]

23 hours ago, KSMooniac said:

Current project is deleting the pop up roof scoop and forward COM antenna. I

How many knots are you hoping to gain from that?

[KSMooniac]

How many knots are you hoping to gain from that?

10 knots! I'll be happy with 3. Or just anything I can detect, actually. It's a labor of love... Lots of labor in a hot hangar! A sane owner would've just bought a newer Mooney.

The best part will be the better overhead vent solution that is very much needed.

Smooth belly is coming up next, but after OSH since the roof improvements are taking longer than hoped.

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[KSMooniac]

Forgetting Mike 201er?
163KTAS, 139KIAS, 161GS, 9000ft, 11C OAT, 21.9”MP, 2620RPM, 63%HP, 8.4GPH, 10LOP, 2150lbs GW

Sorry, Mike! I didn't forget... I never knew your J was that fast/efficient! I knew you did long flights and now that helps explain it. Did you do a lot of optimization, or just luck-of-the-draw end up with a fast one? (Perfectly straight and rigged from the factory)

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[201er]

7 hours ago, KSMooniac said:

 

 

Sorry, Mike! I didn't forget... I never knew your J was that fast/efficient! I knew you did long flights and now that helps explain it. Did you do a lot of optimization, or just luck-of-the-draw end up with a fast one? (Perfectly straight and rigged from the factory)

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It used to be a slow one. 140-148 cruise on 8-8.5gph. Now 150-160 cruise on same fuel. A lot of small mods over the years that didn’t seem to add up to anything but then when I got it repainted, jumped about 8 knots. But it wasn’t just paint. New windshield, windshield cap, body work, etc. It all came together since.

[ArtVandelay]

It used to be a slow one. 140-148 cruise on 8-8.5gph. Now 150-160 cruise on same fuel. A lot of small mods over the years that didn’t seem to add up to anything but then when I got it repainted, jumped about 8 knots. But it wasn’t just paint. New windshield, windshield cap, body work, etc. It all came together since.

I went through the same (our Js were probably built within a few weeks of each other), same results. I’m faster when up north in cooler/dryer air, slower in Florida. I remember seeing your plane on Fort Pierce ramp, a lot of paint chipping on the leading edges as I recall…crucial for low drag to keep the leading edges smooth for low drag.

[KSMooniac]

Maxwell told me long ago the best speed mod is cold, calm day!  He's correct. 

[jetdriven]

On 6/14/2022 at 1:46 AM, KSMooniac said:

10 knots! I'll be happy with 3. Or just anything I can detect, actually. It's a labor of love... Lots of labor in a hot hangar! A sane owner would've just bought a newer Mooney.

The best part will be the better overhead vent solution that is very much needed.

Smooth belly is coming up next, but after OSH since the roof improvements are taking longer than hoped.

Sent from my LM-V405 using Tapatalk
 

I see you did what I did. Beefed up the flange on the dorsal fin then countersunk it with flush rivets 

[graham28105]

I'm just gonna ask. Did the original poster retract the gear? It's a huge speed mod.

[jetdriven]

On 6/16/2022 at 7:48 AM, jetdriven said:

I see you did what I did. Beefed up the flange on the dorsal fin then countersunk it with flush rivets 

 

[Ragsf15e]

3 minutes ago, jetdriven said:

 

Yeah it’s fast, but you’re permanently NORDO and lost!  Where the heck did hide the comm and gps antennas?

[jetdriven]

7 hours ago, Ragsf15e said:

Yeah it’s fast, but you’re permanently NORDO and lost!  Where the heck did hide the comm and gps antennas?

The GPS antennas are here. The COM 1 is right before the dorsal fin. 

[Ragsf15e]

3 hours ago, jetdriven said:

The GPS antennas are here. The COM 1 is right before the dorsal fin. 

Very slick.  The airplane looks real good that way.

[jsm]

Surprising to me how much variability it seems in the speeds of "different" 201's.  My 77' 201 is stock except for the Firewall forward HP+ conversion (10:1 compression pistons).  Just returned from BWG at 9,000'. 22"/2350 rpm, operating 10-20 degrees LOP.  This equates to about 55-65% power.  Full fuel, two passengers, baggage, etc (120 lbs below Max Gross weight). TAS entire trip varied between 155-159 knots (averaged about 157 kts..  variable depending on up/down drafts).  peak EGT 1300; peak CHT 365; OAT 14C. Fuel flow in cruise at this power setting/altitude (per fuel flow meter) varied between 7.8-8.0 gph. These are routine numbers that I have achieved over many years of flying with this plane.  

Have never tried to duplicate the "201 advertised maximum speed" since I am reluctant to run it a full power/rich at low altitude to duplicate the book numbers, but I have little doubt that it would do so.  (also there is a MP limitation on the STC at low altitude.. .so full-throttle below 1800' is prohibited). On shorter trips at lower altitudes and higher power settings I have routinely seen cruise speeds of 165 kts (burning >10 gph)..  

I wonder if the variability in cited performance numbers reflects variations in airframe trim and drag + variations in engine tune/condition? 

Just my two cents!  

jon

 

[jetdriven]

5 hours ago, jsm said:

Surprising to me how much variability it seems in the speeds of "different" 201's.  My 77' 201 is stock except for the Firewall forward HP+ conversion (10:1 compression pistons).  Just returned from BWG at 9,000'. 22"/2350 rpm, operating 10-20 degrees LOP.  This equates to about 55-65% power.  Full fuel, two passengers, baggage, etc (120 lbs below Max Gross weight). TAS entire trip varied between 155-159 knots (averaged about 157 kts..  variable depending on up/down drafts).  peak EGT 1300; peak CHT 365; OAT 14C. Fuel flow in cruise at this power setting/altitude (per fuel flow meter) varied between 7.8-8.0 gph. These are routine numbers that I have achieved over many years of flying with this plane.  

Have never tried to duplicate the "201 advertised maximum speed" since I am reluctant to run it a full power/rich at low altitude to duplicate the book numbers, but I have little doubt that it would do so.  (also there is a MP limitation on the STC at low altitude.. .so full-throttle below 1800' is prohibited). On shorter trips at lower altitudes and higher power settings I have routinely seen cruise speeds of 165 kts (burning >10 gph)..  

I wonder if the variability in cited performance numbers reflects variations in airframe trim and drag + variations in engine tune/condition? 

Just my two cents!  

jon

 

how were you measuring TAS

[PT20J]

There are a lot of variables. Eliminating measurement error would be helpful when making comparisons.

tas_fnl3.pdf