MS3X'd FD

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Dwduc
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MS3X'd FD

Postby Dwduc » Mon Feb 13, 2017 9:14

About a month and a half ago I ordered a DIY MS3X kit from DIY Autotune. I took apart a spare OEM ECU and unpinned the connector to make a PNP pigtail so that I can continue using the OEM computer until I am satisfied with the tune and operation. The ECU assembly was relatively easy, just a BUNCH of soldering and assembling. Once it was together I am unable to do much during the week due to my living situation :rolleyes: . The following weekend I was able to plug it in and start fussing with it, I was very unprepared for how much tinkering and tweaking it was going to take to get the MS to play well with the factory Mazda VR timing system. This weekend I finally got to playing with it some more and finally achieved a clean stable tach and trigger signal to get going. So now the tuning starts! I set up a very basic tune to get started and will be putting around on that for a few days. Once I get it where I trust it to be in a safe running condition I will start configuring the turbo sequencing system. I have also purchased some parts to build a piggyback OMP controller that will be installed once I have a chance to log some data as to the control parameters of the OEM system operate. The prototype controller will be clunky and big but once it is proven to work I will need to find someone that makes circuit boards. I have DIY them in the past but was never happy with the result. Overall I'm very happy with the choice but wouldn't recommend it to anyone who doesn't want to spend crazy amounts of time perfecting it.

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Shadowden
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Re: MS3X'd FD

Postby Shadowden » Mon Feb 13, 2017 9:14

Sweet! Good to hear the new ecu is working out. Will you be puttering around with the oem ecu in hand?

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Dwduc
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Re: MS3X'd FD

Postby Dwduc » Tue Feb 14, 2017 9:14

Actually I made a standoff bracket and mounted the MS to the oem ECU. Still haven't done much tuning wise, just making sure everything is set up right and solid.
ecus.jpg
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Shadowden
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Re: MS3X'd FD

Postby Shadowden » Wed Feb 15, 2017 9:14

Nice arrangement. Standoff bracket bends look nice. What did you use to make them?

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Dwduc
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Re: MS3X'd FD

Postby Dwduc » Tue Feb 21, 2017 9:14

Went over to Shadow's to use his driveway for some tuning. Finished up some work on my pigtail harness and started it up. We got the Idle functions, and the fan control nailed down pretty good, also had it revving out unloaded really nice so we went for a little tuning drive. First 1/3 of the drive went absolutely great, was getting a good, very rich (13:1) base tune set in and then things started going wrong. Car kept cutting out suddenly and then recovering when we were nearly to a stop, wouldn't free rev unloaded and would surge fairly violently during acceleration. we limped it back to his driveway and tinkered with it some with no real solution. I had to get going so I plugged the stock ecu back in and was barely able to get it started with that. Assuming it was flooded and fouled, and that it would get better as I drove it. Which it did somehow, by the time I got where I was going it was running strong and normal. Shut it down there and attended my girlfriends farewell party (she starts a new job tomorrow). And go to leave and the damn thing barely starts, though better than it did at Shadow's. get it going and it will not run in boost, just leans out and sounds like a machine gun. acted like the MAP was unhooked but it was not. at one point I thought I would clutch in, shut the engine off, let the wheels turn it for a bit to clear it out, then key back on. Well the engine did not start firing again when I keyed on and coasted from 65mph to a stop with no sign of life about 3 miles from home. Starter crank with no luck, so I crawl into the passenger floorboard and twist and mess with the harness where it meets the ecu (there are some old unused "scotch splices" there where the car must have had a piggyback at one time. Then she fires right up and runs like a champ. So I'm thinking I have an intermittent short or open in that part of the harness and that is likely what caused the issues when we were trying to tune also, since I have the wires pulled a little to reach the Megasquirt. I'll have some time to mess with it tomorrow, probably pull those splices off and do some wire repair.

vierte
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Re: MS3X'd FD

Postby vierte » Tue Feb 21, 2017 9:14

How do you like the MS3X so far? I decided to upgrade the MS1 V3 to an MS3X for the vert build.

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Dwduc
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Re: MS3X'd FD

Postby Dwduc » Wed Feb 22, 2017 9:14

Well it is my first exposure to Megasquirt. I'll say that it has a very steep learning curve! I have only previously tuned computers that were already designed to operate the engine they were installed on, so when they say "you will learn more than you ever wanted to know about engine management" they mean it!

But all considered I really like it. it's an awesome computer and has more features then you can get anywhere else (if you have the patience to set them all up). All of the problems I have come across so far have been my own fault through not fully understanding how to set it up. And there is very little info on installing one of these on a stock rew that I could find. I am very happy with the product and the education and actually glad that I went this way vs the Adaptronic or Pfc that I was also considering, Once I get all of the silly configuration issues and the new harness issue sorted I think I will be ready to run on it and excited for how it will help on track. I am setting up the sequential turbo switch-over in it which seemed to be working when Shadow was driving and I will be able to control it much more accurately as well as install a simple switch that will allow me to operate it non-sequential on track days.

TL;DR - Two thumbs up, I just need to be smarter.

vierte
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Re: MS3X'd FD

Postby vierte » Wed Feb 22, 2017 9:14

Ha. Yea.. it's definitely a learning experience! I'm pretty familiar with the MS in general but the ms3 chip and the ms3x expansion card are new to me. I do like the easy of getting all the features you want with the combo. We used to have to design and build individual electronics circuits for each input we wanted. If you ever hit an unexpected problem and need a hand, give me a shout. I've built 4 or 5 megasquirts for various applications. (Mostly rotary)

My only complaint is the db37 connectors. They function just fine.. but they really aren't an automotive grade connector and are definitely not moisture resistant. To solve that, I'm building my own enclosure with ampseal connectors.

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Dwduc
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Re: MS3X'd FD

Postby Dwduc » Wed Feb 22, 2017 9:14

Cool, thanks.

It is a cool combo, I get carried away in my mind with what to do with all the extra I/O on this board. I am working on an individual circuit to drive the omp that I might get your opinion on. I need to log the movements it follows with the stock ecu and base the scale off of that. Basically a directional bipollar stepper driver activated by some OP AMP comparitor circuits on the feedback rheostat and the engine load signal. to determine direction and pots for hysteresis.

I agree that the connectors are quite cheesy. I am curious to see your enclosure, problem is the board is set up so well for that connector. Are you gonna run flying leads directly from the board to the AMP connector? I had thought about doing that to my oem connector that I am using as a pigtail but the box isn't shaped for it.

vierte
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Re: MS3X'd FD

Postby vierte » Wed Feb 22, 2017 9:14

I've always been a pre-mixer so I've never attempted to control an OMP. I do have a four channel data logger tho which would be pretty easy to make log the OMP feedback as well as some other signals to approximate load for the stock ECU controlled OMP. Unfortunately I don't know of a simple way to really log actual load. Frankly I don't even know if the OMP is controlled off of load with the stock ecu. S4 rx7's controlled the rate off of throttle position which is a fair indicator of load. S5 and on I have no idea.

Idk how familiar you are with electronics (sounds like you are fairly)... but there may be an easier way to control it. If I'm reading this it sounds like you intend to bring an analog load signal out of the megasquirt. With a simple microcontroller, you could read the load value, drive the stepper motor, read the feedback and apply corrections. You could even do some things like a flow rate curve, pump fail alarms, an on the fly rate adjustment using a pot. Just a thought.

I'll post some photos up soon of the enclosure. This version will still use the DB37's inside of the case but to the outside will be an ampseal connector. If I were building an MS from scratch, I would just run jumper wires from the MS through board holes to the ampseal connector. Then I would de-solder the db37 on the MS3x and do the same. It's just too much of a head ache trying to desolder 2 db37's. There are some nice looking enclosures available for pretty cheep that would fit the stock ECU plug. I think I have $30 for my enclosure.

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Dwduc
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Re: MS3X'd FD

Postby Dwduc » Thu Feb 23, 2017 9:14

The more I look at it, the more I like the micro controller idea. I had originally considered that but dismissed it for being over the top. But looking at how to get an analog signal out of the MS might be very difficult. I can easily configure a PWM signal that is based off of a small map as an ouput that could be read by something like an arduino micro to then signal the stepper driver. Output map could be based off of MAP vs RPM, or fuel load vs RPM. that would get me a more accurate view of engine load then TPS alone. Premixing has always made me nervous but so many people do it with no problems. Do you leave fuel on, on overrun to make sure you still get some oil in there? Seems like more of a flame thrower than I would want.

vierte
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Re: MS3X'd FD

Postby vierte » Thu Feb 23, 2017 9:14

I never have left fuel on. My thought was it's such a brief time and I was already premixing at a higher then necessary ratio that there was enough residual oil to keep things protected. Now here's a crazy thought.. a friend of mine pioneered a mod to the stock omp to use a reservoir of two stroke oil instead of the crank case oil. If that same mod could be applied to the electronic omp, you could use a microcontroller to run the pump and could incorporate a level sensor in the reservoir for low level alarms. That way you get the best of both world.. appropriately meetered oil with clean oil injection and some safety features.

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Dwduc
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Re: MS3X'd FD

Postby Dwduc » Thu Feb 23, 2017 9:14

Rotary aviation sells just such a device. I think Eric has one on his car. It is on my list of things to purchase. I had thought about milling one out but it's one of those things where it would cost me more to make it then they sell it for.
I was thinking about premix only when I did my rebuild, I intentionally started paying attention to time off throttle and there was frequent interstate off ramp situations where the car was coasting and turning the engine at 3k for over 30 seconds which was my internal time limit to start worrying about that stuff.


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