G1000 % of Power

[Tom F]

Does anyone know if the G1000 has the capability to display the % of power.  Possible software update?  Thanks for the feedback.  BTW I was quoted $10,220 for the SVT unlock recently.

[exM20K]

That sounds high for SVT but serves as a reminder: don’t lose your SVT unlock card!

you have %power via fuel flow multiplier if you’re flying LOP, which of course all the cool kids do. I don’t remember what it is for higher compression engines, but it’s better than the 13.7 we use for the turbos.

 

-dan

[LANCECASPER]

45 minutes ago, Tom F said:

Does anyone know if the G1000 has the capability to display the % of power.  Possible software update?  Thanks for the feedback.  BTW I was quoted $10,220 for the SVT unlock recently.

No none of the Mooney G1000 airplanes display % of power. That's available in the POH. Garmin and Mooney work together on what is displayed. I don't think you'll ever see % power happen. There are way more pressing things they need to update. (support for an FS210 to transfer flight plans, NXi upgrade path, etc)

The SVT unlock for the G1000 has always been +/-$10,000 since it came out in 2007-ish. Mooney's list price on it is over $12,000. Once you've flown with it though you won't go back.

[buddy]

If your going to get the SVT unlock card you might as well get the TAWS-B unlock card also for about $8,000. As far as a software update the newest version is 0401.37. I don’t know all of the new enhancements but one of them is it now allows you to receive FIS-B weather although I haven’t tried it yet because I just recently had it installed by Premier.

[jlunseth]

I have percent power on my JPI. I ignore it. There are two completely different measures, one for ROP and one for LOP. The unit has no way of knowing whether the engine is operating LOP v ROP and in my aircraft it applies the wrong formula most of the time. When I do operate ROP, it appears to me the algorithm is off by about 8%, that is, if it is reporting HP is 75% it is actually around 68-69%.

[PT20J]

George Braly (GAMI) has stated that most engine monitors %power indications are pretty inaccurate. He developed a proprietary algorithm for Cirrus for the Avidyne system that Cirrus shared with Garmin. I think that’s what is in my G3X as it seems pretty reasonable. Without giving away too much detail, George described it to me thus:

The algorithm does a basic check to figure out from MP/RPM/OAT/FF   if the engine is ROP or LOP and then  calculates the HP accordingly.
 

[Tom 4536]

On 1/24/2023 at 8:41 AM, jlunseth said:

I have percent power on my JPI. I ignore it. There are two completely different measures, one for ROP and one for LOP. The unit has no way of knowing whether the engine is operating LOP v ROP and in my aircraft it applies the wrong formula most of the time. When I do operate ROP, it appears to me the algorithm is off by about 8%, that is, if it is reporting HP is 75% it is actually around 68-69%.

On my JPI 900 I can switch between ROP & LOP modes by tapping one button. If the button is labelled LOP, then tapping it once switches the unit to LOP mode; at that time the button label will switch to ROP. My %HP reading is about 8% lower in the JPI LOP mode than in the JPI ROP mode. My LOP %HP readings are within a few percent of the theoretical %HP numbers calculated by the formulas I picked up from MS.

[hais]

On 1/24/2023 at 3:34 PM, PT20J said:

I think that’s what is in my G3X as it seems pretty reasonable

The certified version shows % power? When I read the manuals, I only saw MP/RPM/FF. I've seen photos of the experiential version showing % power, so I concluded it was one of those nice features not available to us. 

Is it a hidden setting?

[PT20J]

16 minutes ago, hais said:

The certified version shows % power? When I read the manuals, I only saw MP/RPM/FF. I've seen photos of the experiential version showing % power, so I concluded it was one of those nice features not available to us. 

Is it a hidden setting?

Should be there if it was properly set up in configuration mode

[0TreeLemur]

On 1/24/2023 at 11:34 PM, PT20J said:

George Braly (GAMI) has stated that most engine monitors %power indications are pretty inaccurate. He developed a proprietary algorithm for Cirrus for the Avidyne system that Cirrus shared with Garmin. I think that’s what is in my G3X as it seems pretty reasonable. Without giving away too much detail, George described it to me thus:

The algorithm does a basic check to figure out from MP/RPM/OAT/FF   if the engine is ROP or LOP and then  calculates the HP accordingly.
 

Wouldn't it be awesome if George Braly published his data?   If not that, work with the engine monitor companies to develop algorithms to keep us out of Busch's "magenta box".  I understand that those data required years and lots of $ to collect.  They would be very useful for making the next generation of engine monitors.

[jlunseth]

3 hours ago, Tom 4536 said:

On my JPI 900 I can switch between ROP & LOP modes by tapping one button. If the button is labelled LOP, then tapping it once switches the unit to LOP mode; at that time the button label will switch to ROP. My %HP reading is about 8% lower in the JPI LOP mode than in the JPI ROP mode. My LOP %HP readings are within a few percent of the theoretical %HP numbers calculated by the formulas I picked up from MS.

I can also switch my 930 from ROP to LOP, but once the lean find process is started it can’t be switched back to ROP. In the 231, if you are Rich of Peak and then you put the 930 in LOP mode and lean over to the LOP side, the readings you get on EGT and when the last cylinder peaks are completely invalid. The reason is that the 231 has an interlink between fuel flow and MP. This is different from most other aircraft. So when you start to lean the fuel out the MP changes with it. The assumption of the LOP mode in the JPI is that when you pull the fuel back, all other things remain equal, meaning especially that the MP does not change as you lean the fuel. Other turbo’d aircraft have wastegate controllers that will keep the MP where you originally set it, so if you set it at 32” and then lean the fuel out in LOP mode on the JPI, the MP will stay at 32”. If the MP and fuel flow are both changing your are completely changing your power setting, you are not changing the air/fuel ratio much if at all, and that is what Lean of Peak is about, changing the air/fuel ratio. You will definitely wind up with a lower power setting, but you have no idea whether you are Lean of Peak, or if you are, how many degrees lean of peak you are. Probably you are still Rich of Peak just at a lower power setting.

If the newer JPIs have been changed so you can switch back and forth between LOP and ROP that would be great, but I kinda don’t think so.

[Tom 4536]

8 minutes ago, jlunseth said:

I can also switch my 930 from ROP to LOP, but once the lean find process is started it can’t be switched back to ROP. In the 231, if you are Rich of Peak and then you put the 930 in LOP mode and lean over to the LOP side, the readings you get on EGT and when the last cylinder peaks are completely invalid. The reason is that the 231 has an interlink between fuel flow and MP. This is different from most other aircraft. So when you start to lean the fuel out the MP changes with it. The assumption of the LOP mode in the JPI is that when you pull the fuel back, all other things remain equal, meaning especially that the MP does not change as you lean the fuel. Other turbo’d aircraft have wastegate controllers that will keep the MP where you originally set it, so if you set it at 32” and then lean the fuel out in LOP mode on the JPI, the MP will stay at 32”. If the MP and fuel flow are both changing your are completely changing your power setting, you are not changing the air/fuel ratio much if at all, and that is what Lean of Peak is about, changing the air/fuel ratio. You will definitely wind up with a lower power setting, but you have no idea whether you are Lean of Peak, or if you are, how many degrees lean of peak you are. Probably you are still Rich of Peak just at a lower power setting.

If the newer JPIs have been changed so you can switch back and forth between LOP and ROP that would be great, but I kinda don’t think so.

My newer JPI CAN change between LOP and ROP. Obviously you feel you know more than JPI. Too bad.

[jlunseth]

No, sorry, I didn’t mean my comments to be critical. However, the JPI does not know if you are LOP or ROP. It has no fuel mixture sensor. It makes assumptions and applies an algorithm based on those assumptions. As I said, those assumptions apply to most aircraft but not to our 231s.

Edited January 31, 2023 by jlunseth

[Pinecone]

12 hours ago, PT20J said:

Should be there if it was properly set up in configuration mode

That is for the G3X/EIS.

The OP was about G1000

[LANCECASPER]

14 hours ago, Tom 4536 said:

My newer JPI CAN change between LOP and ROP. Obviously you feel you know more than JPI. Too bad.

And it looks like you feel you know more about the Mooney 231/JPI 930 combo than @jlunseth. It looks like you've owned your 231 about 3.5 years. Even though I owned a 231 for about the same length of time (May 1993 - September 1996) and flew it almost 400 hours before I bought a Bravo, my knowledge didn't scratch the surface compared to  @jlunseth. On this forum he is the most knowledgable and helpful on the 231, having owned his airplane coming up on 14 years . Most likely he has flown behind the JPI 930 in a 231 more than anyone else on the forum. Personally, if I owned a 231 I would want to be kind to him so I might be able to call on him when needed.

@kortopates is the most knowledgable and helpful on the 252 (or Encore) and @donkaye is the most knowledgable and helpful on the Bravo. 

Even though I have some time in all three of these airframes I defer to them and appreciate all of the help they provide to Mooney owners on the forum. 

[PT20J]

2 hours ago, Pinecone said:

That is for the G3X/EIS.

The OP was about G1000

True, but I was responding to @hais question about the G3X

[Pinecone]

3 hours ago, PT20J said:

True, but I was responding to @hais question about the G3X

Missed that.  Sorry