Megasquirt 2 in parallel with factory ECU
#16
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resolution is what im after. Im a visual learner. If i cant see something it takes me longer to understand it. dont get me wrong i like my EMU but when it offers options like flex-fuel and the ability to control 2x 1200cc injectors on 2 different maps while also making sure my target A/F is keep in check then yea ill keep it. Right now its good at 361hp. You dont learn anything by playing it safe and if it takes something breaking then ill know how and why it happened and it will never happen again. For me that's MS! I'm just looking to get some help understanding what most likely i already know. The information ive gotten so far from everyone's input has help me out big time and thank you very much for.
If you think there is more to the greddy unit than im seeing then im willing to put MS aside and learn more. Never hurts to learn or be given good advice.
If you think there is more to the greddy unit than im seeing then im willing to put MS aside and learn more. Never hurts to learn or be given good advice.
#17
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JP1=OPEN
JP2=OPEN
JP3=OPEN
JP4=OPEN
JP5=OPEN
JP6=OPEN
JP7=1-2
JP8=2-3
JP9=OPEN
JP10=1-2
JP11=OPEN
JP12=OPEN
JP13=OPEN
JP14=OPEN
JP15=2-3(from coil not ECU)
JP16=OPEN
JP17=1-2
JP18=OPEN
JP19=1-2
JP20=1-2
~Vehicle~
Engine Code: Universal
# of Cylinders: 6
Engine Size: 3000
Airflow Meter Type: Hotwire
Airflow Meter Spec: TY_HM-5
RPM Signal Type: RPM signal
Crank Angle Type: TY_2
Off Set angle: 0 (at the moment)
Vehicle Speed Pulse: 4
Vehicle Speed Adj.: 100%
Thats the EMU settings im using atm.
JP2=OPEN
JP3=OPEN
JP4=OPEN
JP5=OPEN
JP6=OPEN
JP7=1-2
JP8=2-3
JP9=OPEN
JP10=1-2
JP11=OPEN
JP12=OPEN
JP13=OPEN
JP14=OPEN
JP15=2-3(from coil not ECU)
JP16=OPEN
JP17=1-2
JP18=OPEN
JP19=1-2
JP20=1-2
~Vehicle~
Engine Code: Universal
# of Cylinders: 6
Engine Size: 3000
Airflow Meter Type: Hotwire
Airflow Meter Spec: TY_HM-5
RPM Signal Type: RPM signal
Crank Angle Type: TY_2
Off Set angle: 0 (at the moment)
Vehicle Speed Pulse: 4
Vehicle Speed Adj.: 100%
Thats the EMU settings im using atm.
#19
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did you base it off an existing harness? if so which one? i am about a week from wiring in my MS V3. I just finished the board mods last night and am too runing ignition through the factory ECU to control the ATX trans
#20
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I'm interested to see how splitting the CAM and crank position signals will work. From what I have read on the MS forums this can be difficult since these are weak signals, prone to noise--even when going to one board--this is why they have special conditioning circuits. Make sure to run devoted signal and grounds from each sensor to each ECU.
I too am attracted to the advantages of piggybacking onto the factory ECU. The factory likely has done a superb job tuning sequential injection at low load conditions--better than we can do. They also have probably done a fantastic job with cold starting, and idle control. They devote row after row of temperature controlled dyno cells for this task. When I built a MS2 for my subaru these things were very frustrating to sort out--early morning -10 degree cold start enrichment tuning is not fun.
Correct me if I am wrong, but from my MS tuning experience--and I had a decent running setup--the MS does not rely solely on the TPS. I believe it used this sensor mostly for accel and decel enrichment, which are set and forget tables that only correct the main VE table. I would contend that the main tuning parameter is the surface plot of RPM vs MAP vs VE.
I too am attracted to the advantages of piggybacking onto the factory ECU. The factory likely has done a superb job tuning sequential injection at low load conditions--better than we can do. They also have probably done a fantastic job with cold starting, and idle control. They devote row after row of temperature controlled dyno cells for this task. When I built a MS2 for my subaru these things were very frustrating to sort out--early morning -10 degree cold start enrichment tuning is not fun.
Correct me if I am wrong, but from my MS tuning experience--and I had a decent running setup--the MS does not rely solely on the TPS. I believe it used this sensor mostly for accel and decel enrichment, which are set and forget tables that only correct the main VE table. I would contend that the main tuning parameter is the surface plot of RPM vs MAP vs VE.
#21
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This is why I left my standalone for a stock 2jzgte ecu. it cold starts perfect, it idles perfect, it runs perfect, and it boosts perfect but a little on the rich side in full boost compared to a standalone, which is not a bad thing because it allows you to turn up the boost some from stock without a piggyback. Best part is all the piggybacks actually work well with this ecu, unlike the stock ge ecu which starts to "freak out".
have you guys not read my tt ecu mod? Don't waste your time piggybacking the stock ecu, especially with a megasquirt which is supposed to be a standalone really, I am aware you can piggyback it but why you would want to is not really clear, even if you have the MS in parallel, if you want to use the stock ecu for the low load conditions, it will still freak out when that maf sees all that extra air, it wont drive well even in low loads once it sees boost because it instantly fuel corrects and next time you idle it is usually very off.
If you want to run like factory, and have an ecu that understands what to do with boost, tt ecu mod is a good route to go, and only takes a handfull of wires, sensors, coils, and larger injectors.
https://www.clublexus.com/forums/sc-...t-ecu-mod.html
tach signal you should be getting from the ignitor, which you will need to keep for MS. you can also try tapping the IGF signal. all sensor grounds are gounded to the intake.
have you guys not read my tt ecu mod? Don't waste your time piggybacking the stock ecu, especially with a megasquirt which is supposed to be a standalone really, I am aware you can piggyback it but why you would want to is not really clear, even if you have the MS in parallel, if you want to use the stock ecu for the low load conditions, it will still freak out when that maf sees all that extra air, it wont drive well even in low loads once it sees boost because it instantly fuel corrects and next time you idle it is usually very off.
If you want to run like factory, and have an ecu that understands what to do with boost, tt ecu mod is a good route to go, and only takes a handfull of wires, sensors, coils, and larger injectors.
https://www.clublexus.com/forums/sc-...t-ecu-mod.html
tach signal you should be getting from the ignitor, which you will need to keep for MS. you can also try tapping the IGF signal. all sensor grounds are gounded to the intake.
Last edited by Ali SC3; 10-22-12 at 09:41 AM.
#22
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This is why I left my standalone for a stock 2jzgte ecu. it cold starts perfect, it idles perfect, it runs perfect, and it boosts perfect but a little on the rich side in full boost compared to a standalone, which is not a bad thing because it allows you to turn up the boost some from stock without a piggyback. Best part is all the piggybacks actually work well with this ecu, unlike the stock ge ecu which starts to "freak out".
if you want to use the stock ecu for the low load conditions, it will still freak out when that maf sees all that extra air, it wont drive well even in low loads once it sees boost because it instantly fuel corrects and next time you idle it is usually very off.
if you want to use the stock ecu for the low load conditions, it will still freak out when that maf sees all that extra air, it wont drive well even in low loads once it sees boost because it instantly fuel corrects and next time you idle it is usually very off.
Anyway I think you are my long lost brother. I too have an SC, and a 1985 toyota pickup and was born in CO. haha
#23
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Thank you for this information. I sort of overlooked the fact that many factory ECUs "learn". I wonder if there is a way to trick it; low pass filter on the MAF??
Anyway I think you are my long lost brother. I too have an SC, and a 1985 toyota pickup and was born in CO. haha
Anyway I think you are my long lost brother. I too have an SC, and a 1985 toyota pickup and was born in CO. haha
No problem, The 2jzge ecu learns in a really bad way when it sees too much airflow, it starts to react by changing the timing and fuel corrections, but when you stop boosting it doesn't know the corrections are no good anymore and it results in weird things happening all across the board, especially in the low load areas where a small change makes a big difference.
you cannot low pass filter this type of maf easily because it is a Karman type maf which puts out a frequency not a constant voltage. you need a more sophisticated controller like an safc type device and enter lower load values in all the higher load areas, so when the MS takes over in the higher load areas the stock ecu would get low acceptable values. the transition would have to be perfect though, and unfortunately the safc is not a perfect device and the ecu does not always go into open loop at exactly the same times. Im not even sure if the MS does intercept mode, or maybe it could simulate the maf but you could spend all day every day getting this to happen right with 3 different devices, end result will be that the MS alone would do a much better job, which is actually not that bad I hear in regular driving compared to other standalones.
The aem FIC is what you probably should look into it was designed to do intercept if you want to do that it is basically a combination of all of those, all the signals go through it and then to the ecu and vice versa, so it keeps the stock ecu as happy as possible, while taking over at a programmed point. people normally use these on vvti cause keeping the stock ecu is a much easier route to go on those vehicles, but for odb1 non vvti the better route is to swap ecu's.
I Personally like my tt ecu mod, because for the same price as the stuff that can barely do the above right, I have a turbo factory ecu with full coil on plug ignition. the GE ecu will almost always be limited to one coil without alot of complications. basically you get much more by just changing to a turbo ecu, and everything is factory buttery smooth. My car is really a pleasure to drive on the aristo ecu, it never idled and revved so clean on anytthing else I tried and I have tried many.
Last edited by Ali SC3; 10-23-12 at 10:57 AM.
#24
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Sorry i haven't posted anything after getting the system installed. In the end Megasquirt is now a standalone. All sensors but the TSP have been changed to GM's, the TPS is that of the Q45's. I ran in to the issue of to many wires and signal noise clouding out the VR signal for the 24-1 wheel set up i was using.
#25
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I had a feeling you would end up using it as a standalone, it really is much less complicated that way.
sure the stock ecu has great drivability, but that goes out the window when you slap a turbo on it even with tricking.
are you running a custom trigger setup or is it happy now that the stock ecu isn't involved.
sure the stock ecu has great drivability, but that goes out the window when you slap a turbo on it even with tricking.
are you running a custom trigger setup or is it happy now that the stock ecu isn't involved.
#26
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Sorry i haven't posted anything after getting the system installed. In the end Megasquirt is now a standalone. All sensors but the TSP have been changed to GM's, the TPS is that of the Q45's. I ran in to the issue of to many wires and signal noise clouding out the VR signal for the 24-1 wheel set up i was using.
When I do an install for Megasquirt I leave the oem ECU in the car sometimes as a means for the client to save a couple bucks. The stock ECU has a great algorthym for controlling the idle and unless you have MASSIVE injectors or crazy head/cam work it is typically sufficient. It also means wiring the a/c triggers do not need to be done or the EFI relay....granted, not a ton of work, but time is $.
You can run the MS along side the OEM ECU sharing the stock crank/cam sensors but it requires proper filtering and triggering on the right edge of the sensor. In addition, our VR sensors are getting VERY old, so replacing them isn't a bad idea. They are pretty cheap from places like rock auto.....
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