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Which analogs instruments to leave in panel. GRT Sport EX install

N333M

Active Member
I am considering which of the old instruments to leave in the panel. Airspeed of course, turn and bank, maybe altimeter..maybe not, if there is room. But I would also like to have a few engine gauges.
My question is, can one run the single signal wire to a resistive element analog gauge, like the fuel levels, or the oil pressure, and to the GRT EIS 4000 together? Will they read correctly?
thanks,
Don
 
What to leave would be determined by your mission and trust in the GRT system. As for engine gauges, I have never tried to run two systems off of one sender, but I am sure some would work and others wouldn?t. The GRT system sometimes uses pull-up voltage to convert a resistance sender into a voltage input, which would likely cause the standard gauges to be unreliable. Having the other instrument connected to the sensor should not change the GRT usability, because you can calibrate the GRT to work with just about any voltage input by adjusting the scale factor and offset to get the accurate value to display on the screen.
 
What to leave would be determined by your mission and trust in the GRT system. As for engine gauges, I have never tried to run two systems off of one sender, but I am sure some would work and others wouldn?t. The GRT system sometimes uses pull-up voltage to convert a resistance sender into a voltage input, which would likely cause the standard gauges to be unreliable. Having the other instrument connected to the sensor should not change the GRT usability, because you can calibrate the GRT to work with just about any voltage input by adjusting the scale factor and offset to get the accurate value to display on the screen.

With the exception of the oil pressure. They have this hard coded to work with the VDO sensor that they spec/supply. No scale factor/offset available.

Larry
 
As Jesse said, you can calibrate the GRT to read accurately if, say, the fuel level sensor is loaded by an analog gauge. But, if the analog gauge fails, then the GRT won?t read correctly either. I?d use the panel space for independent, back up flight instruments.
 
I am considering which of the old instruments to leave in the panel. Airspeed of course, turn and bank, maybe altimeter..maybe not, if there is room. But I would also like to have a few engine gauges.
thanks,
Don

I left the oil pressure gauge and sender as a back-up...... That's the one gauge that would make me get on the ground asap. The senders do have a high failure rate.
 
oil press

Gasman,
thats kinda what I was thinking, oil pressure would be nice to have backed up with analog. Did you run the single signal wire from the VDO sender to both you analog gauge AND the EIS? or leave it out of the EIS ?
Don
 
Gasman,
thats kinda what I was thinking, oil pressure would be nice to have backed up with analog. Did you run the single signal wire from the VDO sender to both you analog gauge AND the EIS? or leave it out of the EIS ?
Don

Already had Van's OP gauge and sender mounted on top brace. Just installed a "T" and added VDO sender for MGL Xtreme.

The only sender that worked double was Van's tach sending unit works his tach and the Xtreme tach with no problem.

The back-up oil pressure gauge is not for EMS failure...... it is for sender failure which is way more common, and could cause you a lot of stress as you fly along looking for a place to land before the motor fails. A look at the back-up oil gauge would tell you the severity of the problem.
 
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I built mine with backup airspeed and altimeter (early dual dynon glass) and I also wired the oil pressure sensor to a master caution light in the panel.

I have had one instance where the glass went dark due to overheating on the way to Vettermans in South Dakota and the analogue instruments with the 796 worked out fine.

It took me a while to get used to looking at the glass as primary but I do like having the backups and I do try to keep the analogue altimeter in sync.

Some of my buddies decided on no backup analogue instruments so that they had to concentrate on the glass display and were not distracted, just different philosophies.

I do have to say that other than the one overheat situation (I now blow air around the back of the panel, RV-7 slider) the dynons have been rock solid since 2008 so reliability does not seem to be a big issue with glass cockpits.

Your call really.
 
I have zero analog engine instruments to duplicate EIS 4000 data. My thinking is that an electrical failure and loss of EIS data is one of two things: not critical since my engine is not electrically dependant or critical because I have lost other functions unrelated to engine indication. In neither case do I need analog engine instruments.

In regards to analog backup flight instruments, that is a personal choice. For VFR, none. For IFR it depends on your skill at flying partial panel. It can be done with as little as airspeed, altimeter and turn and bank. In my case, I chose airspeed, altimeter, Trutrac horizon, whiskey compass. And the answer is that they DID save my bacon once when the EFIS went TU in the soup. The event was almost a non-issue with the backups.
 
For my IFR panel, I went the same route as Figs, only because I had the space for Airspeed and Altitude so what the heck, and I am an Idiot, so I need an Idiot light for some things, to include oil pressure. Admittedly, that light does require electricity. So as an IFR panel, I spent a lot of time making sure all things requiring electricity had a graceful degradation to multiple backup sources of ship's power. If I fry all the wiring on the plane, I have an attitude and navigation source driven off a standalone battery, but would lose all engine monitoring, to include oil pressure.
 
I have a large red lamp wired to an oil pressure switch but mine is primarily a "Turn Off the Master You Idiot" light...... :(

It also has a loud audio transducer in the circuit (with a kill switch for maintenance chores).
 
Something like this makes much more sense to me than a bunch of "steam" gages.
cf-lg.jpg
 
One of my aircraft has a Dynon panel (VFR mission) while the other has GRT (IFR mission). The Dynon-equipped ship has ASI, ALT, VSI, T&B steam gauges. The GRT ship has no steam gauges. I'm comfortable in either airplane.

As for engine instruments, I'm in the "keep it simple" camp. The engine monitor runs on the main electrical bus. I have an oil pressure switch and red LED annunciator lamp on the panel, powered by the essential bus. In the event of a failure of the main bus, the only engine instrument I have is the oil pressure idiot light. Works a charm for me (and I like seeing the light extinguish within a second or two of the engine firing, while the engine monitor indication takes a few more seconds).
 
geez I love this place!

Gents
I am truly enjoying all this discussion, and Walt, I got one a those!
so far the panel is from left to right..Garmin G5, GRT sport EX, 3 1/8 pitot airspeed and below it either T&B, or altimeter. So theres triple redundance in flight insturments.
Above the radio stack, (King76 and garmin SL40) is the GRT EIS 4000. And the 2 1/4 Vans transducer tach . I will wire my tach function on the EIS to the mags, so theres RPM redundancy.
Still have room for a couple more of those original 2 1/4 engine gauges. so oil pressure will probably be one..I like the dual sender unit idea Gasman, hadnt thought of that! , one more 2 1/4 hole avail, not sure which other to put there..but its alot of fun thinking thru the possibilities.
Plenty of room on the right for the Ifly 740 or the ipad mini, which i have both and have been flying with trying to decide which is best. After 80 hours on the plane this summer, I like the Ifly 740 because I can read it so much better, and it never overheats and quits like the ipad does..but I do like the Foreflight program alot on the Ipad.
 
I started with an AS, altimeter, and slip ball. Then when I replaced my Dynon D100 and D10 with a Skyview I left them out. However, I did put a Pocket Panel in at that time.
 
Seems to me the days of those instruments are gone with the rotary phone. Not that long ago many people had a analog backup instruments. They have been replaced with smaller efis units like the G5 or the GRT Mini. Not that analog instruments don't have some utility but they are dated technology that will just devalue your investment. An oil pressure switch and indicator take care of the low oil pressure warning condition if you want an independent check. That is what I'm planning. I'm sure I'll hear about these comments. Each to his own.
 
I've got a GRT Sport SX, but put a steam ASI and altimeter alongside the display. I like to cross-check the EFIS with the steam gauges. I'll admit that part of the reason is aesthetics....I like a couple of round dials to break up the rectangular monotony.
 
Backup instruments

I bought a very inexpensive MGL 2" Infinity instrument which allows 4 temps and one pressure input. Mine is set up to give me oil pressure and CHT's. I also have analog fuel level and fuel pressure gauges. My EFIS is backed up with a G5.

My sending unit manifold is kind of crowded, and I had to wire in a switch to switch the fuel level senders between the EFIS and gauges, but if my EFIS goes out in the soup, I should be OK.

John
 
I've got a GRT Sport SX, but put a steam ASI and altimeter alongside the display. I like to cross-check the EFIS with the steam gauges. I'll admit that part of the reason is aesthetics....I like a couple of round dials to break up the rectangular monotony.

Exactly....... Nothing more boring than walking up to a nice RV at Oshkosh and looking at the panel to see nothing.... nothing but black shut off screens and a few switches..............:(
 
Exactly....... Nothing more boring than walking up to a nice RV at Oshkosh and looking at the panel to see nothing.... nothing but black shut off screens and a few switches..............:(

In that case I see lots of dollar$$$....and huge technological capabilities....

Those round clock dials look exactly the same as they did sixty years ago.....kinda boring, eh?

To each his own. :)
 
Exactly....... Nothing more boring than walking up to a nice RV at Oshkosh and looking at the panel to see nothing.... nothing but black shut off screens and a few switches..............:(

.....and like looking into the cockpits of new turbo-props, corporate jets, Boeings, Airbuses......, all with glass screens and a few switches.

From my years of experience flying glass panels since the mid 90s, I felt very comfortable equipping my RV with only glass displays. My experience is that the glass has been a lot more reliable than the iron gages I used to fly with back in the 60s, 70s, 80s, and 90s.
 
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