EDM930 vs MVP-50

[panther1400]

Heard of JP Instruments but not much about EI.  With the rebates JP has the 930 is alittle cheaper than the MVP-50(dont know if one or the other costs more for installation) is the EI worth more for features or is the layout better?

[danb35]

I can't directly compare the two units, but you won't find better customer or technical support than with EI.  I've heard bad things about JPI's service, but I don't have any experience with them myself.

[DaV8or]

I'm struggling with the two options myself. I intend to go to the AOPA meet in Long Beach and demo them both. I like the extra features on the MVP-50, but the 930's display looks a bit nicer. However, the MVP-50 may have a better user interface. I currently have a JPI EDM 700 and I'm not all that impressed with it. It does what it's supposed to, but I don't find it very user friendly. I'm hoping that both companies have made improvements in this area. A live demo is the only way I can tell. I'm also hoping I can get a show special price.

[panther1400]

Let me know what you come up with.

[jlunseth]

I have the 930.  I don't know anything about the EI except what I have read on their website.  I know that the 930 is what you want with an engine instrument panel that is primary, and that is bulletproof and well organized.  I have not had it fail for any reason in the 100 or so hours I have had it in the plane.  It is well laid out.  From what I have read on their website, the EI is a little more customizable.  One needs to consider the practicality of some customizations, however.  For example, I don't see any use for a checklist on the primary engine display.  I have that capability on my 430AW and never use it.  A paper checklist is much handier and allows the use of the instrument for the instrument's primary function, which in the case of the 430 and during pre-flight, is nav set up, and in the case of the engine analyzer is getting engine readouts as you work through the pre-flight checklists.  I don't mean this as a "knock" on the EI instrument at all, it looks like a very good instrument and I have no experience with it, as I said.  I have just found that all the "nifties" just aren't so nifty in a practical, functioning cockpit and you wind up not using them.

So my advice is figure out what you actually need the instrument for, and ignore those things that you don't need it for.  Then compare units.  

[carusoam]

Dave,

You could have the JPI

Or you could have the EI

They both have a lot of functionality.

You may need an associates degree in computers to fly your plane when you are done.

Best regards,

-a-

[jlunseth]

Ain't that the truth.  You already need a law degree to carry the FAR/AIM in your flight bag.  Engineering degree would be handy.

[jezzie]

This is a great advantage having all this experience on this site, so here I go again asking for advice/experience on one analyzer over the other. Main focus is quality and after sales service. I phoned EI and they were very helpful but also higher in price when every thing was considered for a Mooney. JPI's sales manager said that the fuel pressure was included, and I can't remember the specifics from EI. I was at JPI's office yesterday basically to clarify the order and unfortunately some confusion exits. I was happy with my decision to use the 930, but now find that I may have to do some more due diligence and ask more questions.

All of your opinions are important

Thank you

Eldon M20J

[Jeff_S]

Quote: jlunseth

Ain't that the truth.  You already need a law degree to carry the FAR/AIM in your flight bag.  Engineering degree would be handy.

[jlunseth]

The only issues I had with the installation of my 930 were issues relating to the establishment of a couple of redlines, and really not the fault of JPI or my installer for that matter.  JPI sends a questionnaire for you to fill out, and they also want a copy of the engine page from your POH.  They use the engine page to establish the redline limits programmed into the 930.  The problem in my case is that two of the redlines on my JPI are not really valid.  They are not a very big deal either though.

The first issue was the fuel pressure redline.  The POH does not provide a fuel pressure redline, there is none.  I don't know how the redline was picked, but it is too low, so I get an Alert on every takeoff when the engine is at max.  My A&P now has the ability to reprogram the redline, so that will get fixed at the next annual.  I has no consequence, except that I get an Alert during every takeoff and need to hit the button to clear the alert.  Nothing of any consequence happens if I don't clear the Alert either, it is just an annoyance. 

The other issue is the Compressor Discharge Temperature.  My aircraft originally had the TSIO-360-GB and then was converted to the LB.  When the conversion was done an Intercooler was added.  Both the GB and the LB have a redline for the CDT of 280 dF.  However, the question I had was whether that redline is at all valid in an engine that has an intercooler.  There are two possible purposes for the redline if you think about it, one is as a readout of the health of the turbo (how hot is it running), and the other is as a readout for the induction air going in to the induction system.  If it was intended as the latter (induction air temp) it would no longer be valid, because my JPI also reads Induction Air Temperature, which is the temp of the air after the intercooler and just before it goes into the induction system. 

I asked a couple of companies that are authorities on this and the answer was the same, the CDT was meant as a measure of induction air temp, to prevent overly hot air from causing detonation in the engine.   The limit on the turbo is TIT (there is another redline for that).  So I suppose I am going to try to get the A&P to reprogram the unit to show a graph of IAT instead of CDT, and make the 280 dF limit the one for IAT.

Neither of these has any consequence on how the engine operates.  The moral of the story though is to think through your readouts and alarms and figure out what you are really going to need.  JPI wanted or possibly for regulatory reasons needed to stick to the POH limits. 

One of the coolest things about the 930 is the ability to store all the flight data from the engine and graph it out.  It is worth learning to use this, since it allows you to "see" some engine issues when they are just starting, and before they become an issue in flight.  The GAMI course was great on that score.   

[DaV8or]

Just to muddy the waters a bit, there is also the Ultra Electronics AuRACLE CRM2100.

Advantages are,

It is compatible with existing JPI probes, so speeds up install time.

Has patented redundant analog instrument lights in case the display dies.

Used defined bugs for the power settings.

Disadvantages are;

Most expensive.

Limited authorized installers.

Does not do fuel level, so you still need independent fuel gauges.

 

[carusoam]

JL,

Great dissertation on modern engine instrumentation.  I believe this, in combination with your turbo knowledge and previous experience, makes you a subject matter expert on this topic.

By chance, have you asked JPI if they can supply you with an oil level sensor?  Why wait for oil pressure to drop to emergency levels when you may be able to sense a middle level like (4qts).  I am sure "quick drain" issues have been removed from your list, but other things could pull the same mean trick.

Dave,

If you leave the photos attached at the bottom of your post, they will stay in the body of your post.

Best regards,

-a-

[jlunseth]

Would be nice to have oil level yes, I'll vote for that.

I guess it was kind of a dissertation, sorry, but the deal is that there is a little bit of a pucker factor when you get a redline alert.  On both of those, I had to figure out pretty quickly and in the air if it was important or not important.  I guessed right (not important).  You can bet I looked into it when I got on the ground.  Don't want to overreact to the not important.   

[carusoam]

JL,

I meant dissertation in a good way....  I really appreciate the technical discussions.  It gave me something mooney related to think about while spending hours mowing and moving leaves today.

So this is what I thought.  (The FAA may think differently....)

[1] For engine health, you definitely want intake air temperature and manifold pressure as close to the intake as possible. 

[2] For the health of the turbocharger itself.  TIT is important as this is the heat going into the drive side of the turbo (turbine inlet temperature).  Very similar to EGT.  It gets very hot and the turbo has its limit there.

[3] The value of knowing the temperature between the turbo and intercooler is simply to identify how well the cooler is working.

You can now compare OAT to CDT (temperature rise during compression)

You can compare CDT to Intercooler exit temp. (temperature drop provided by the intercooler)

Your real redline for engine health should be based on the air temperature entering the engine.  Ideally the same redline that came from CDT prior to intercooler installation.  Unless there was some correction for instrument error or placement.

Your real redline for turbo health should be exhaust temperature enterting the turbo (TIT).

The temperature exiting the compressor does not create an alarm worthy piece of data that I can think of.

[4] Fuel pressure often has a top limit.  I think it was put there in the event of blockage due to ice or other substances.   It would give you the hint something is not right before destroying the pump.  My M20C would indicate higher pressure on colder days, near its redline.  I am not sure how much the viscosity of fuel increases in winter (I am guessing not much) but something was changing.

On the other hand.  I cannot find a fuel pressure indicator in my M20R.  Excess pressure in the fuel injection system returns fuel back to the tank.  I do have a fuel flow indicator, so I have some indication of pressure.  There is nothing available or valuable to set a red line to in this case.

Best regards,

-a-

[jlunseth]

You have everything exactly right on the temps.  I was concerned about the CDT redline because that is in the POH, and because I see temps over the CDT redline when trying to fly about about FL210.  My theory is that (1) the air is thinner, so cooling is poorer even though ambient temp is very low, and (2) the wastegate is fully shut or nearly so, thus putting the entire exhaust stream into the turbo.  The turbo is working at max.  So the temps were persistently creeping up into the 285 - 290 area.  Normal efforts to cool things down seemed to work inversely, in other words, I would typically make the mixture a little richer and that would cool everything off, EGT, CDT, TIT.  However, making the mixture change at that altitude had the opposite effect, CDT went up. 

I guessed that in my engine set up, CDT was not longer a valid redline, and the engine seemed ok with that.  Have talked to engineers since then who know what that CDT redline was designed for, and they said exactly what you did, CDT redline was to protect the engine from high induction temps causing detonation.  The limiting factor for the turbo operation is TIT, and I was well under that, so everything was ok despite exceeding the redline. 

In my plane (231) you do theoretically need to know CDT-IAT.  Turboplus gives you a table for calculating what MP you need to operate at, to reach a desire % HP using the numbers in the POH.  In other words, it tells you how much of a downward adjustment you need to make in the MP given that the induction air is cooler (therefore denser) than the POH anticipates.

In theory you are right on fuel pressure.  What is going on is that there was no good information to set the FP redline (nothing in the POH), so somebody picked an incorrect number.  The A&P (Willmar) now has the ability to reprogram this limit in the 930, so they are going to adjust the redline at annual.   In the meantime, I ignore it.

The moral of the story for those looking at an engine analyzer, regardless of mfr., is that if the analyzer is going to be STC'd as primary, it will be required to show redlines.  It may take a little study to get those redlines right in light of the fact that many of the Mooneys have been modified from factory, changing how everything relates.

[jezzie]

Anyone who saw the booths at AOPA care to share their impressions/ differences between JPI 930 versus EI's MVP-50

 

Eldon

[DaV8or]

OK, so here's the run down as I saw it-

The EDM 930 and MVP-50 are so close to each other that it's like Ford and Chevy, or Coke and Pepsi. For all intents and purposes they are the same size, same price and same function. Which ever you prefer will come down to your own preferences.

Display

Here I thought the 930 had a tiny little edge. It just seemed a wee tad brighter and maybe a bit crisper. On the other hand, I likeed the MVP-50's side by side tach/MP layout better than the 930 over under. On the other other hand, the 930 breaks EGT and CHT temps into two seperate displays where as the 50 combines them. Both display all other perameters in a linear tape style gauge. You see where this is going...

Functions

Both units replace all the factory engine gauges and have an automated function to help you lean. Both have audio and visual alerts with external annunciators. Both have data tracking. Differences are, the MVP-50 offers vacuum pressure and the 930 does not, so for those with vintage Mooneys with only a high and low annunciator, it may be of value, but it costs extra as does fuel quantity. Fuel quantity is included with the 930. The MVP-50 annunciator is just a red and yellow light that will light when any engine function exceeds programed limits. The 930 has a very cool digital alpha numeric display that reads tach and MP when everything is going normal, but will read out a warning when something is a miss. This little display is very handy for those of us that have to mount the monitor on the far right of our panels. On the other hand, I would think that a red light out of nowhere is more likely to get you attention quickly than a new set of text on unit that is always displaying text.

The MVP-50 can also be configured to lots of other aircraft functions displayed if you wish, like flap position, or de ice fluid level. However, I kind of found this to be like bells and whistles, but I guess could be very meaningful to some. The data wrangling on the JP unit seems to be handled with software they provide where as EI uses a third party software company solution. Both are USB and do their updates this way.

User Interface

Users of the JPI EDM 700 or similar are already familiar with the 930's interface. It's a row of buttons with a "step" button and a certain amount of button combos to get where you want. The MVP-50 works more like a Garmin 430. It has a rotary knob to switch screens, press to select and a menu button. Both units are complex and will take a bit of learning and that's to be expected of a device that does so much, however I found the MVP-50 to have the clear edge here for me. Bottom line for me was when I asked for demonstrations by the very knowledgable people manning the booths, the JP guy stumbled and got lost more than once on his machine. The EI guy always knew where he was and where I was when I flailed at first. In the end I found the EI machine and it's Garmin style interface to be much more to my liking.

Intallation

Both units are physically about the same size in all directions. The EI unit includes a sort of hub that is independent of the display that mounts on the inside of the firewall. This allows all the various cables and wires from the engine compartment to stay on that side and a single cable to run from it to the display. Kind of nice for cleaning up behind the panel. I beleive that the JP unit has multiple cables running to the display. Both comapanies will credit you for probes and sensors that you don't need because you already have them installed. People with say a EDM 700 can use all their probes and sensors over on either unit if they wish. JP probes do work on EI units. This can save you a little bit of purchase price and install time, however, probes and sensors do age, so you might want to change them all anyways. I probably will.

Bells and Whistles

The MVP-50 offers a lot more bells and whistles than the 930. It can do weight and balance calculations, check lists, timer and clock and I think even more. All the extra stuff is kind of neat, but I didn't put too much value on it because I already have devices that give me this info. Still, we shall see...

Conclusion

In the end I chose the MVP-50. I ordered it and got a little show special price. It was actually a tough choice. I really liked the remote tach and MP display that came with the 930, but in the end it came down to user the interface for me. The MVP-50 felt more intuitive too me and I figured that if a guy that works for JPI for a long time and demos the unit all day long at trade shows can get lost, I don't stand a chance bouncing around in the cockpit. I also liked the vacuum option as well. Hopefully I chose well, only time will tell.

Oh, and of course, YMMV.

[jlunseth]

Great report!  The only thing I would add is that it doesn't take much practice to learn the JPI controls.  JPI needs a new sales guy it sounds like.  Also, alot of the "bells and whistles" aren't worth having and don't get used.  You better have your w & b worked out before you get in the plane.  You don't want to be in a position of climbing in and starting the engine (to power the analyzer), before you check to see if you can fly.  I have too much of that stuff on my 430AW.  A paper checklist is alot faster than paging through an electronic device also, and you want to move smartly through your runup so as not to pick up a lot of rocks going through the prop, so better not to be punching too many buttons during that part.  Some of the other stuff on the EI would be cool though, flaps for example.  Just remember, for each one of those there is a sensor, and the installation of a sensor, and some weight added to the aircraft, so the bill goes up and the useful load goes down.

[fantom]

What I like about JPI is that they have been around for a long time, and all they do are engine analyzers.

[danb35]

Quote: fantom

What I like about JPI is that they have been around for a long time, and all they do are engine analyzers.

[jlunseth]

Yes, I may have said it earlier, but I have their Superclock and it is the best timer and clock I have used.  Their customer support is really great, frankly better than JPI.  I have dealt with customer support at both companies.  The EI people sound like they actually like to talk to you, the JPI people would just as soon do something else. 

[fantom]

Interesting, because I've never had an issue with JPI customer service, and I've had one since 1994. They've even given me several extra probes and a SW upgrade at no charge at Sun N Fun.

[jezzie]

Thanks DaV8or, good report. I also went with the MVP-50 mainly cause of what my avionics shop said, ease of installation. I won't use all that it does but did add the fuel level. Vacuum and airspeed optionsI am still considering. EI people were very helpful, and the AOPA discount helped. Plus they could have it made in a week versus 2 weeks.

 

Eldon

 

Eldon

[jlunseth]

Give us a PIREP when you have had a chance to use it a little bit.  We would all find it really helpful. 

[flight2000]

Does the EMD or MVP come with all of the cables/probes required or are they sold separately?

Brian