1992 M20J Panel Upgrade / Advice

[gevertex]

7 hours ago, ArtVandelay said:

Is speed brake problem for both sides or just 1?

I had problems with my AHRS and they replaced it, then had problems because it was not configured properly, you will see errors in the logs stored on the SD card.

How do you know which RPM reading is correct?

Hold menu key on power up gets you into the configuration menus, you can fix a few of your problems yourself if you want.

Right side speed brakes. Left side is quiet.

There is only 1 RPM reading. Settings were set to 2600 RPM and engine sounded like 2600 RPM. Plane climbed well also, but RPM read only 2270

I will definitely make some adjustments at some point, there was just enough that I sent it back to the shop.

[gevertex]

6 minutes ago, Evan said:

How are you getting RPM? Assuming via pleads? 

It's something similar to this. A&P showed me one time in the shop.

https://www.pilotshop.com/catalog/inpages/jpi10-05459-61.php

I believe it works on halls effect.

[M20F-1968]

On 1/26/2023 at 1:33 AM, carusoam said:

G hit a really good point… (above)

Check where the steel tubes go…  the center tube turns into an inverted Y…

This is why the audio panel is always at the top of the stack… it is a really short box.

Best regards,

-a-

Or you can modify the structural cage as I did and make it look like to new models.  Just need a DER, a DAR,  and some time and Money.

John Breda

[gevertex]

1 hour ago, Evan said:

When you go into the config mode, is the right sensor selected? There are only a couple of hall effect sensors it works with. 

Good question. I didn't have the sense to check it when I was there. Shop is taking a look today. I'll let everyone know what they find. I did notice some fluctuation on the RPM value while on the ground a few times. Might be a bad / loose sensor.

[201Mooniac]

2 hours ago, Evan said:

When you go into the config mode, is the right sensor selected? There are only a couple of hall effect sensors it works with. 

Those sensors are also notorious for not working, connecting directly to the p-leads is more reliable.

[gevertex]

1 hour ago, 201Mooniac said:

Those sensors are also notorious for not working, connecting directly to the p-leads is more reliable.

Welp, hopefully they can get it fixed quickly. The more you know, right?

[ArtVandelay]

Right side speed brakes. Left side is quiet.

Then probably a limit switch has gone bad, you can try electronic cleaner on it. This is likely because when switches are not exercised for a while, then they tend to get corroded, so not something the shop did.
Mechanical devices like to used but not abused.

[201Mooniac]

7 hours ago, gevertex said:

Welp, hopefully they can get it fixed quickly. The more you know, right?

Hopefully yours is one where it works.  I had one that worked for awhile and when it failed, the new one(s) wouldn't work.  I also had an experience on a bravo with a JPI and the Hall effect sensor and it never worked in years of trying.  When I moved from the JPI to the GI 275 the shop wired to the p-leads and it seems very stable.

[gevertex]

1 hour ago, 201Mooniac said:

Hopefully yours is one where it works.  I had one that worked for awhile and when it failed, the new one(s) wouldn't work.  I also had an experience on a bravo with a JPI and the Hall effect sensor and it never worked in years of trying.  When I moved from the JPI to the GI 275 the shop wired to the p-leads and it seems very stable.

That doesn’t sound fun. RPM is pretty important. Hopefully mine is easier. 

[gevertex]

On 5/9/2023 at 8:42 PM, 201Mooniac said:

Hopefully yours is one where it works.  I had one that worked for awhile and when it failed, the new one(s) wouldn't work.  I also had an experience on a bravo with a JPI and the Hall effect sensor and it never worked in years of trying.  When I moved from the JPI to the GI 275 the shop wired to the p-leads and it seems very stable.

Its interesting, I wonder how this is supposed to work. Usually with halls effect sensors you have a magnet mounted to the spinning part you want to measure RPM of and then the sensor mounted to something fixed near by (in this case the magneto case). It's usually pretty straight forward unless there is a lot of EMI nearby. I wonder if you lost your magnet or if the engine bay is a particularly EMI rich environment. I can imagine a magneto would throw off plenty of EMI.

[gevertex]

The shop is just about done with the corrections. To the point made earlier, the RPM sensor has been a bit of a problem. They were only able to get to ~100rpm of the measured value.

 

Good news I didn't share earlier: Useful load is now 1039lbs. Net removed ~50lbs of stuff from the airframe. It was really hoping to get useful load over the 1k mark. Now it's firmly there.

[gevertex]

Been flying a bit, but been working on the list of squawks (down to the last two now). This airplane sat for long time before I had it and I've been slowly dealing with all of the issues.

Question for the group. How does this look performance wise. I know the RPM sensor is off (it was fixed after a second visit back to the avionics shop). Prop is set for 2700rpm in this photo. Airspeed seems a little low to me, but looking at the POH the TAS is 6kts under. Fuel flow also seems a little high. What does anyone who has experience with this model think? I just don't have a ton of experience with this airframe, so hard to know that is normal. I was expecting closer to 155kias from my limited experience prior to the avionics upgrade.

 

[Brian E.]

@gevertexYou mentioned the prop is set for 2700 yet the picture shows 2300 so when you mention that your prop is set for 2700 I presume you have the prop control full forward?  If your fuel flow is calibrated it seems wicked high for cruise flight. With that in mind I think you may be in flaming dragon mode: 24/27 (MP/RPM) and full rich.  The key number for the M20J is 47 for 65% power or 50 for 75%.  Many would recommend keeping the throttle wide open and pulling the prop back to get to your desired key number.

  Awesome plane, awesome panel!  

(edited after I reread your post on the rpm sensor)

Edited July 4, 2023 by Brian E.
Accuracy

[gevertex]

6 minutes ago, Brian E. said:

@gevertexI'm confused. You mentioned the prop is set for 2700 yet the picture shows 2300.  If your fuel flow is calibrated it seems wicked high for cruise flight.  I don't know if you've leaned yet in this picture but it would seem leaning woudl improve your performance.

 

  Awesome plane, awesome panel!  

Thanks! RPM sensor is malfunctioning in this pic. Prop is set to full forward though (2700RPM). Throttle is also full forward (still in break in period). I am running a little rich (127ROP) need to run it leaner. 

[ArtVandelay]

Oil pressure and temperature is low.

Edit: and your CHTs are a bit high for that fuel flow.

[gevertex]

1 hour ago, ArtVandelay said:

Oil pressure and temperature is low.

Edit: and your CHTs are a bit high for that fuel flow.

Oil temp probe was replaced subsequent to this.

Oil pressure was also turned up subsequent to this.

Good point on the CHTs. What would you expect for that fuel flow? Cowl flaps were closed fully FWIW. I landed once I realized Oil temp was probably incorrect.

[ArtVandelay]

Oil temp probe was replaced subsequent to this.
Oil pressure was also turned up subsequent to this.
Good point on the CHTs. What would you expect for that fuel flow? Cowl flaps were closed fully FWIW. I landed once I realized Oil temp was probably incorrect.

Id expect CHTs around 350°, I only see 390° on climbs. I always cruise RPMs 2400-2500 and LOP so only can compare to my climbs with cowl flaps open but airspeed of only 100 knots.

[gevertex]

14 hours ago, Brian E. said:

@gevertexYou mentioned the prop is set for 2700 yet the picture shows 2300 so when you mention that your prop is set for 2700 I presume you have the prop control full forward?  If your fuel flow is calibrated it seems wicked high for cruise flight. With that in mind I think you may be in flaming dragon mode: 24/27 (MP/RPM) and full rich.  The key number for the M20J is 47 for 65% power or 50 for 75%.  Many would recommend keeping the throttle wide open and pulling the prop back to get to your desired key number.

  Awesome plane, awesome panel!  

(edited after I reread your post on the rpm sensor)

Good tip on key numbers, I just read about them as a result. I like the concept. Makes power management a lot easier. 
 

I am currently running it full out for break in. I did have the prop back to 2600 roughly but with the inaccurate RPM decided to push it up to 2700 for the picture so that I could compare TAS and power setting to POH more easily later. 
 

I was just a little surprised that the indicated airspeed wasn’t higher, but looking at the book + historical photos in cruise that is the same speed I was making prior to avionics install. So it checks out. 

 

I was just able to dig up this photo I took prior to the install. Everything looks identical except RPM and Oil temp. Hopefully those are resolved. I plan to pickup fly her again next weekend.

Edited July 4, 2023 by gevertex
Found another picture.

[gevertex]

2 hours ago, Evan said:

Also, how many hours are on the engine? Could your high CHTs be from the rings not being broken in yet?

~20 hours on the engine. So yes, thats a good point. It's not done being broken in yet.

[gevertex]

3 hours ago, Evan said:

The speed is in the ballpark of what I would expect at 75% or greater on power. The FF is questionable. You can calibrate this in the G3x. Compare the fuel totalizer to the actual fuel burn after a fill-up. I'd compare it against a couple of fill-ups before changing it. Mine is within 1%.

 

Also, I don't see the % power showing up on the engine page. If you are running the latest FW, it should be there if the model engine is set correctly. 

I might need to look at the calibration. I'll try one more time first though when the RPM is working properly and set it exactly to book numbers (including mixture) / check the fuel flow.

 

Interesting on % power, I hear it's in the config. I'll ask the avionics guys. That would be even easier than a key number for sure.

[gevertex]

On 5/13/2022 at 9:36 PM, Niko182 said:

Fly the plane for 100 hours and then do the panel. Youll figure out what you like and you dont like.

Just wanted to add that I came back to this after the fact and agree with you 100%. It would have made a lot of my progress a lot easier.

[gevertex]

Overdue update. Shop fixed RPM sensor and it's dead on now. They commented they are using a p-lead based sensor. I did get % power to show, and calibrated the fuel flow. It looks a lot closer now than prior. Engine has ~27 hours now.

Airplane has been flying pretty good. Getting her flying at least 2x a week at this point.

[gevertex]

Hey All,

      I've flown the panel quite a lot. I noticed ADS-B in viewed on the G3X Touch from the GNX 375. I compared that with Sentry and ForeFlight. I found the G3X is sometimes missing some targets on the map. The avionics shop chalked it up to a software issue, reloaded the software, and promised to look at it again if I continued having issues. They also mentioned that the G3X could be combining targets in a similar area. Interested to hear everyone's thoughts as none of this seems right to me.

 

[EricJ]

15 minutes ago, gevertex said:

Hey All,

      I've flown the panel quite a lot. I noticed ADS-B in viewed on the G3X Touch from the GNX 375. I compared that with Sentry and ForeFlight. I found the G3X is sometimes missing some targets on the map. The avionics shop chalked it up to a software issue, reloaded the software, and promised to look at it again if I continued having issues. They also mentioned that the G3X could be combining targets in a similar area. Interested to hear everyone's thoughts as none of this seems right to me.

 

If your panel is getting ads-b-in from an in-panel source rather than from your Sentry, then there will be natural differences between what they display for potentially several reasons.   ADS-B-in data can be obtained from two different sources, essentially UAT and 1090-ES, as well as direct transmissions from aircraft within line-of-sight to your antennas.   If the panel source and the Foreflight source (sentry) aren't receiving the same sources there will be differences in the display.   If they aren't using the same antennas (which is usually the case), then they won't have the same view of potential sources, either transmitting towers or aircraft transmitting directly.   

I see this all the time, where there is traffic on my panel displays (from an in-panel FreeFlight Ranger) but not on my EFBs fed by a Stratux and vice-versa.    The antenna that feeds my in-panel source is exterior on the belly, and the stratux is fed by antennas mounted in the cabin on the B-pillars on either side of the airplane.   They won't see the same signals all the time.

[Niko182]

It’s because your setup has an altitude range. Foreflight doesn’t have an altitude range set up so it will show all targets at the way up to 51000ft. The G3x is setup to probably show targets within 2000ft of your altitude. Pretty sure that can be adjusted in the settings, which is why in this case the target 1000ft above you showed up but not the 2 targets 4000ft and 4800ft below you.