JPI 730

Big Ed

Big Ed

N50247 - '79 Super D
Joined
Jul 20, 2020
Messages
1,938
Location
Tampa, FL
In my determination to completely overanalyze my engine monitor decision, I am taking another look at the JPI EDM-730. Starting to think it is the best fit for my needs and wants.

EDM730.webp

Initially I was turned off by the lack of primary capability. The 730 is STC for secondary only, meaning you have to leave all your old instruments and gauges in.

But, am starting to realize the flip side of that is flexibility. With the 730, you can buy the base model for $1550, which gets you EGT/CHT. Then in the future you can add whatever additional sensors you want, all the way up to the full 830 setup. The display automatically configures to the new inputs, so no sending it back to the factory.

So, I don't have to spring for $4K for a full monitor now. But later on, I can add fuel flow, oil temp, and oil press for a few hundred bucks each.

My steam gauges work fine for oil T and P. However, I confess I don't monitor those as closely in flight as I should, like most pilots I suspect. The idea of having an alarm to alert me to problems is appealing.

I don't really see the need for MP and RPM. My tach is new and works fine, and steam MP gauges are easy to replace and cheap to overhaul.

The only big negative is that I would need to rewire my switch panel to add an avionics master. As we have all observed, access to that area is a PITA
 
A few years ago I would have gone along with you and agreed the added capability to supplement the old gauges would be worth the cost and effort. With the new stuff being all inclusive and legal to replace all of the old stuff, I'd say go for the few extra bucks, plan to put in one instrument to replace everything and then start planning the project.

I can see why it would make sense though if you didn't want the added hassle of migrating all of your existing connections and stuff to a new box.

The EDM-900 is a bit of a pain in the arse as they spec the three main sensors need to be firewall or engine mount resident. The factory is doing this now for their EDM-930 installation. It's just a matter of clamping the sensors to the firewall and then running tubing to the engine with firesleeve on it. Fuel pressure, oil pressure, and something else? I forget which three at the moment.
 
I think part of it is related to goals. I bought the plane to meet a short term desire to fly a lot. I am currently leaning away from making the investment to make it my forever plane, because I think I might want to step up in capability in a few years. So, the idea of putting a $4K monitor and $2K of labor into it does not appeal to me right now. I would rather focus on meeting my immediate needs for flying. IMO an EGT/CHT bar graph is my biggest need. The 730 is as cheap as the various 2 1/4" gauge options, but with a larger screen and the option to add more capability later.
 
I can fit the 730 in my panel, but I will have to replace my USB port to do so. The avionics shop installed an Appareo Stratus port. Apparently it will not fit in a 2 1/4" hole, which is idiotic. That's another $300.
 
What won't fit in the 2 1/4" hole? The USB ports? You can make an adapter plate to capture the 2 1/4" hole's four screw holes and a smaller hole in the face for your USB ports. Or is the -730 that needs a bigger hole in the panel?
 
Bartman said:
What won't fit in the 2 1/4" hole? The USB ports? You can make an adapter plate to capture the 2 1/4" hole's four screw holes and a smaller hole in the face for your USB ports. Or is the -730 that needs a bigger hole in the panel?
Click to expand...
Apparently the USB charger case is too large, such that the corners obstruct the 2 1/4" screw holes for the adapter plate. Lots of complaints on the internet about this. It just occurred to me that I could simply rotate it 45 degrees to overcome this issue, so the ports are oriented diagonally on the panel face But definitely a boneheaded design decision.

The other issue is the size of the 730 display. It is 3x4", so it overhangs the 3" gauge hole it is mounted in by 1" in one direction. You can choose the direction. In my panel the only available hole would be to the right of the radio stack, where the USB currently is. The overlap would have to be oriented upwards. By my estimate it would partly cover the 2" gauge hole above, where the factory EGT currently is. I would remove the EGT, so not an issue for that. However, I would have to relocate the USB to the other side of the panel, which isn't great for my ergonomics.

PXL_20210917_025334064.webp
 
Are there any combination gauges you could use to open up some space? Oil temp and pressure maybe? Or manifold and fuel pressure? I wonder if something like this would be legal
www.ebay.com

United Dual Manifold & Fuel Pressure Gauge, P/N: 6331 | eBay

As Removed, Good Condition. Looking for difficult hard to find parts?. We will do our very best to answer them!
www.ebay.com

If you pull the VSI and drop a dual display manifold/fuel pressure gauge in where the current manifold pressure is, a 2 1/4" g-meter would fit where the fuel pressure is then you could pull the VSI and big g-meter for the engine monitor to take both of those spaces.

just spitballing (again!!) but it seems that VSI is where the engine monitor should plug in and then overlap to the right where the g-meter is.
 
Bartman said:
Are there any combination gauges you could use to open up some space? Oil temp and pressure maybe? Or manifold and fuel pressure? I wonder if something like this would be legal
www.ebay.com

United Dual Manifold & Fuel Pressure Gauge, P/N: 6331 | eBay

As Removed, Good Condition. Looking for difficult hard to find parts?. We will do our very best to answer them!
www.ebay.com

If you pull the VSI and drop a dual display manifold/fuel pressure gauge in where the current manifold pressure is, a 2 1/4" g-meter would fit where the fuel pressure is then you could pull the VSI and big g-meter for the engine monitor to take both of those spaces.

just spitballing (again!!) but it seems that VSI is where the engine monitor should plug in and then overlap to the right where the g-meter is.
Click to expand...

MP and FP combined is actually the current factory spec for steam gauges. Gauge is United 6335. That would free up a small hole, but I've got one over there already. It's just on the wrong side of the plane.

If I was going to rearrange things, the quickest path to freeing up a 3" hole would be to install a 2 1/4" MP gauge. But again, I've already got a free small hole over there.

I've been considering rearranging my center 6 pack of 3.125" holes to be more ergonomic for aerobatics. When pulling out of a down line, it is important to monitor airspeed and G. Things are happening fast, and it can be challenging for your eyes to pick up the correct gauge quickly. I'm thinking a more logical arrangement would have the G meter directly under the ASI, and the VSI directly under the Altimeter.
 

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I agree and am doing that with the new panel, g-meter under the airspeed indicator just left of the iPad. no analog VSI though, maybe a digital display on the AV-30.

are there any engine instruments that can be removed with the EDM-730 going in?
 
Just the EGT. That's the big weakness of the 730; it's not primary for anything.

I use the VSI a lot, including during acro. It is useful to verify a level flight path at very slow or fast airspeeds, such as after an Immelman.
 
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I think I have narrowed it down to 2 choices. Both cost $1500.

Aerospace Logic 200
PROS
Fits in 2 1/4" gauge hole
No avionics master required
No change to USB required
CONS
No upgrade capability
Small display

ECT204-a.webp

JPI EDM 730
PROS
Large display
Upgradeable later to display MP, RPM, Fuel Flow, & Oil Temp/Press
CONS
May have to install avionics master
May have to replace USB port

EDM730.webp

The JPI is appealing for future-proofing, but at this point I am in leaning towards the quick and easy ASL.
 
I looked on Ebay a few minutes ago. Several JPI 700 4C 2.25" for sale. People who are upgrading their panels are always selling good parts. A -700 would give you EGT, CHT and voltmeter. When you decide to upgrade it's worth trade in money on newer JPI stuff of just re-Ebay it...

Chris
 
That's an intriguing thought. At the moment I have myself whipped into a frenzy over the EDM 830. Waffling back and forth between that and the ASL 200. Pretty sure I want color regardless.
 
Big Ed said:
That's an intriguing thought. At the moment I have myself whipped into a frenzy over the EDM 830. Waffling back and forth between that and the ASL 200. Pretty sure I want color regardless.
Click to expand...
Now that you've had a week or two for your "whipping frenzy" to die down, have you settled on an EGT display?
😏
Chris
 
Big Ed said:
Lol, nope, waited too long and started imagining my engine needing an overhaul.
Click to expand...
And after you rebuild the engine you're going to want/need an engine moniter. Don't let all this good planning, plotting and scheming go to waste...go for the -730. You know you want it...
Many a good man has been lead astray by his imagination. Don't let the lure of high compression pistons and chrome valve covers do you in...😈👹☠️
Chris
 
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