Megasquirt DIYPNP

[Tommio RS]

Hmmm i see this megasquirt ecu is not looking to bad! I can run many of things its just comprehending everthing thats difficult....

I guess the easy part is making the ecu! LOL

So what is the hardest part? Building a circuit to control the IAC?

Does the legacy even have that??? I have NO clue where it may be.

Feel free to call me a dumb @$$ i just dont know.

As for tuning. Will freeze frame data help out that? I can get like friggen tons of that if i wish.
I have access to the SSMIII and ill just hook up my car and run it.

[fastwagn]

Well, it's officially alive. A 10k resistor in line with the cam signal fixed my rev issue. We still need to sort out proper fueling. At the moment it will rev to about 6200 RPM, but then runs out of fuel. A base tune will make the car drivable and once we shake out the bugs, I can consider it a complete success and share some of our spreadsheet data!

Amazing how one little 10 cent radioshack piece can change the game. The subaru cam signal had an output voltage that was more than the MS could deal with that got worse at higher RPM. That's why it would drop out at 4K. This brought the signal down to make the magic happen!

Jerry - Good to see you on our boards. Justin Gray has been the brains behind this MS project.

i've been following your build as many have been. your tps signal issue intrigued me most. rather than invert the wires as previously suggested (and countered by your own reasoning), i have a bored ee customer that has already started building you an inverter circuit. i'll pm when it's bench tested. that way the idle switch in the tps still works properly. on a related note, does the ms control the iac via steps or pwm (duty cycle)? nvm, reread the site

yes, there is an iac on your legacy. not to be too harsh, but cover your basics in full detail before you start down the road of building a standalone and installing it. even if you had the guys at diyautotune install it, you need to know how/why it works, so when something goes wrong, you are equipped to fix it.

not sure why you would want a maf (jecs or otherwise), thought ms was speed density, i'm not even sure it knows what to do with a maf signal in the diypnp form...

not sure why you'd need an injector box to run new style 550 injectors, they aren't peak and holds.
although i would love to use the ms to run such injectors, i do like ethanol....

using this system with an auto car will require a bit more work than you are planning as well. you will need the tcm shift signal to the ecm to keep the timing retard during shifting intact. otherwise the engine won't "dip" between shifts and you will eat the clutch packs in very rapid succession. this would require some advanced tuning/wiring/configuring of the megasquirt to work properly.

as for the cel issue. this is full standalone, like hydra, aem, link, motronic, etc. but is a diy ecm rather than a sealed box that you wire in. there is no on board diagnostic function, it requires old school diag. read the sensors via dvom, and some from the logs, have some common sense about what the symptoms suggest, repair accordingly. same applies to tuning. pick the values in the ms tuning software logger, interpret the results, (a/f and knock correction rule all ), make appropriate decisions about your tune.

as far as i know, there is no plug in emissions test for obd1. running the ms you have no cel, so no need to control the canister purge function (it won't set a code), or any other superfluous emissions stuff. and as long as you keep emissions equipment visually intact , you're fine anywhere. as these cars age, they will become easier and easier to pass inspections. as an inspector, we were essentially told, anything obd1 pretty much gets an automatic pass, numbers still on the road are so small, governing agencies just don't care. just don't have a bulb out or missing/rusted exhaust, and all should be well.

as for the ssm3, the newest select monitor won't communicate with the megasquirt, ms uses it's own tuning/logging software to do so.

don't get excited about logging your car with the factory ecm either. even with the correct adapter cable to communicate with the obd1 style plug, the ssm3 doesn't have software to work with anything pre-obd2. the last time i asked a subaru rep, i was told they didn't see the point in paying to have the software installed for a small and dwindling handful of pre-obd2 cars that trickle into dealers. may have changed in the last 6mos., but i haven't seen on any updates. the ssm2 will communicate using the adapter cable and the correct nintendo game-er, cartridge. i think it's tan...

not that that's terribly helpful, since the brick is so useless as far as how much data it can actually handle. when you choose more than 4 pids, it blocks the data horribly, and since you can download to a pc easily, it isn't convenient. (and who wants to use the crappy printer they give you, the cash register at target is faster AND clearer) i use my revtronix cable on my car, and i have a brick (sm2).

all in all, n2x4, you are forging a great path, and as jerry said, subarus are running these, but no one is really taking the time to document. kudos. now hurry up and work out the problems so when i am ready to do this in november i won't have anything to sort!

[n2x4]

i've been following your build as many have been. your tps signal issue intrigued me most. rather than invert the wires as previously suggested (and countered by your own reasoning), i have a bored ee customer that has already started building you an inverter circuit. i'll pm when it's bench tested. that way the idle switch in the tps still works properly.

I appreciate the feedback! It's turned into a much slower project than I anticipated, but that's mostly because the car has been stubborn the whole way. Fix one issue and find another!

Everything has been recorded onto the DIYAutoTune wiring XLS template, so once it's done I'll be able to share the results.

For the TPS, we've gone with MAP based acceleration for the time being. It would be nice to get the TPS to work, and if you figured out a circuit to do the job that would be amazing. Tuning and reliable running are the main priorities.

yes, there is an iac on your legacy. not to be too harsh, but cover your basics in full detail before you start down the road of building a standalone and installing it. even if you had the guys at diyautotune install it, you need to know how/why it works, so when something goes wrong, you are equipped to fix it.

This is the TRUTH. Before the megasquirt install I did a full wiring swap into my car. I became VERY familiar with what everything in the car did, where it went, and how it worked. The experience alone has helped immensely with this project.

all in all, n2x4, you are forging a great path, and as jerry said, subarus are running these, but no one is really taking the time to document. kudos. now hurry up and work out the problems so when i am ready to do this in november i won't have anything to sort!

Thanks for the kind words! It seems like everything is falling into place. Coolant temp readings are accurate, radiator fans are working. Car starts and runs, wideband readings are accurate, etc, etc.

I think we may need to change the resistor we're using on the cam sensor for a larger one. The car does indeed rev to redline, but as we've started to tune at specific RPM points we get some dropping out. The thought at this point is that the current 10k isn't large enough to keep the signal where megasquirt likes it.

[fastwagn]

yeah sorry, the middle of that pos was more for tommio than you. i figured you knew where the iac was, tommio was casting some doubts.

[Matt Cramer]

We've made one of the challenges easier - the V1.5 DIYPNPs now have a 3 wire IAC control circuit installed, by popular demand. You'll just need to add a couple jumpers on the main board to enable it.

The current firmware being used in the DIYPNP does not support a MAF, although you can leave the MAF in place if you're keeping your engine compartment looking stock.

[Tommio RS]

Hmm so it does not use a maf. It uses a IAC i guess then.

What sensors can it all run? Or better question what sensors do you need to make the MS and your motor run happy?

[FoundSoul]

There is an optional firmware that supports MAF (the default B&G MicroSquirt firmware) but it would limit many of your other outputs so most do go that route. The MS2/Extra guys are planning to add MAF back to their code at some point, but to be honest the squeaky wheel often gets the grease, and people are so pleased running speed density that there's not alot of people 'squeaking' for MAF support in this code.

Basically you need a MAP sensor (which is built into the MS/DIYPNP)
An IAT, CLT, Tach input, and it will run on that. TPS is optional but recommended. And if you were dead set on it you could do with the CLT, though cold starts and warmup may suffer.

[trell]

Hi Mate awsome thread i have been searching for a few months for someone else who has done one of these kits for the subaru,

I have a V2 STi and i have 95% of the wiring done for it. Was hopeing you would help me out with the last few wires.

Basically i have the three port boost solinoid and was hoping if you could tell me the pins i need to wire the PCB to, to make it work. Also would you send me your base map? I know that mine is only a 2Ltr but it will be a good start?

Kindest regards Tom, Email = Trell@live.co.uk

[sleepinsuby]

Did you ever get all the bugs worked out? Also have you figured out the right (values ) for keeping as meny stock Subaru sensors?

[n2x4]

Never finished this project. The car is still sitting in the garage, with the ECU on the seat. We never were able to overcome the RPM issue. I've got too much money tied up into the project to give up, but it's probably going to sit for a while.

[FoundSoul]

Hit us up on it n2x4 -- at websales@diyautotune.com

We had a 2002 Legacy here recently that we got it up and running on, they guys can likely help you sort it out....

[BoostedSubie]

I planned on going with MS on my new project but i was gonna dump the Subaru trigger and go with the Ford EDIS 36-1 so i wouldn't have to mess around with cracking the factory 6/7 wheel. Hope you figure it out, can't wait to see your results.

[mazda ej22t]

im about to order a package from them. if i am using a dohc from an impreza what trigger wheel should i be getting?

[BoostedSubie]

What year? I ended up going with Adaptronics and I'm using the newer 36-2-2-2 cuz I will eventually be throwing in my EJ255 motor once I finish rebuilding it and that way I won't have to chage stuff too much when I retune it. I think Subaru switched over to the 36 tooth around 2000, before that it used the 6/7 wheel. So, if your cam gear has 7 teeth on it then you want the 6/7 crank wheel to match. I've heard people having more luck with the 36 setup though.

[Legacy777]

Is there any advantage to the newer crank wheel?

Seeing that I'm running my link on the older crank & cam setup, I'm curious if there would be an advantage to going to the new crank gear, & cam pulley setup.

[mazda ej22t]

here is what they quoted me to be getting

MS230-K $266 Megasquirt-II kit with V3.0 PCB
ZealDB1-K $35 Unassembled Zeal Engineering Dual VR Daughterboard
MK-Boost $7.50 Electronic boost control mod kit
EBC_Sol_kit $45 EBC Electronic Boost Control Solenoid Kit
JimStim-K $59.00 JimStim MegaSquirt Stimulator with Wheel Simulator - Unassembled
StimPower $8.99 Power supply for Stim
MSHarness $67 8' wiring harness
IATwPiggy $22.25 Intake Air Temperature Sensor
38NPT-Bung_A $9 Aluminum bung for IAT sensor (Also available in stainless steel)
TuneCable $5.50 6' DB9 tuning cable
USB-2920 $22.50 (Only needed if your laptop doesn’t have a true DB9 port)
Subtotal without wideband -- $547.74


i have my brothers spare heads from an 01 impreza rs. so that should mean its 36-2-2-2 then? anything i am missing from this package they have set up for me or anything i may not need?

im thinking its going to be ej22t block and internals, dohc heads, delta cams and a td04 with yellow tops and an awic.

[AWD_addict]

Judging by the JimStim and cables you're getting ready for tuning, so get a wideband too.

[BoostedSubie]

I don't know if there are any advantages with the newer style crank trigger, I've just heard it is more compatible with Megasquirt as the Subaru 6/7 is an oddball.

[BoostedSubie]

It would seem that one advantage would it being more accurate as it is looking at the crank's angle 36 times a full rotation instead of 6. That is just a guess though as I am just getting into the world of tuning. After I get more familiar, I'm going to run Megasquirt on my other Legacy and my Corolla.

[mazda ej22t]

boosted so do you think mines a 36 tooth with it being 2001? my set of heads are 45 mins away so i cant see it

[mazda ej22t]

actually....maybe its SOHC

[vrg3]

Josh - The newer cam/crank sensor setup is better in principle; it's more precise so it allows the ECU (whatever ECU that happens to be) to get a more precise idea where the camshafts and crankshaft are at any given time. That means that ignition and even fuel timing when you're accelerating is more accurate as a result.

However -- and this is speculation -- I think the big reason Subaru wanted that increased precision was to make misfire detection work better. OBD-II requires the ECU to detect misfire, so OBD-II ECUs watch for little dips in crankshaft acceleration. That works way better with the new setup than the old one, especially with higher-output engines. I don't think the difference in performance is that significant (because for ultimate performance the tune will end up compensating somewhat anyway).

mazda ej22t - Whether it's SOHC or DOHC doesn't really matter. What car exactly is this engine from? Are you talking about the 01 2.5RS heads? Those use the "36-2-2-2" triggers. But to be clear: the actual 36-2-2-2 wheel is on the crank, not the cam. If you want to use an already-implemented decoder, though, you'll need the crankshaft sprocket that goes with the camshaft pulley.

[mazda ej22t]

the heads will be from my 2000 forester which was sohc. i was talking about the rs heads but i forgot i used them on my engine. im not getting it for some reason my bad lol so to use this sohc heads and the megasquirt will i need to swap any wheel or sprockets?

[vrg3]

I'm pretty sure there is MegaSquirt code to use both Subaru trigger setups. You just need the crank sprocket to be of the the corresponding type. I don't know what kind of trigger 2000 Forester heads have. You might have to remove the left cam sprocket and look at the pips on it. If it has two pips about 90 degrees apart, then they have a "new" or "36-2-2-2" setup. If it has a total of 7 pips, in 4 different sets, every 90 degrees, then they have the "old" or "6/7" setup.

The "new" crank sprocket has lots of teeth all around it; the "old" one has just six pips spread out somewhat unevenly on it.

You just need them to match. If they don't, you have to swap one sprocket or the other.

If you use the "old" setup, I believe you need the dual VR inputs. The "new" one works with just the crank input. Here are the MS2-Extra pages about the two setups: http://www.msextra.com/doc/ms2extra/MS2 ... Subaru.htm and http://www.msextra.com/doc/ms2extra/MS2 ... -2-2-2.htm

[Legacy777]

Vikash,

Thanks for the info. Yeah in principle it sounds better.