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Discussion Starter · #1 ·
Working on piggy back system and have most of the materials needed:

coils from matrix
Innovate 02 sensor
wiring block to be able to add/subtract wires
lots of wires
fuse block
male/female automotive quick connects

plan is to create this piggy back system to learn how to do... and maybe turbo the 4age later on...

so far i've spliced:

air temp sensor
coolant temp sensor
crank position sensor
cam position sensor
coil on plugs x4
injectors x 4
o2 sensor
throttle position sensor
idle (next to tps)

this system runs off the vacuum from intake - manifold absolute pressure... so no maf or afm...

now ready to plug in the 40 pin wire block

any one else do this? any improvements on the driveablility?

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Discussion Starter · #4 ·
I have a Speeduino for my V6 swap. I made up a little PCB so I could keep in in the original ECU case. Honestly the stock ECU still runs better than my Speeduino at this point, but that's just because I haven't been able to really get the tune dialed in. On an NA motor I wouldn't expect to really gain much over the stock computer other than experience with the Speeduino and tuning - which is worth a ton especially if you plan to go FI someday.

View attachment 83328 View attachment 83329
wow, that's a much cleaner look and fits so well! i'm using cookie tin and have decided where to put the ecu...
 

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Discussion Starter · #5 ·
What are you trying to accomplish with it?
Why a piggy-back system instead of a stand-alone?
Why speeduino?
i went with speeduino because it appeared to the 'most' open source. megasquirt, haltech seemed a lot more money and my buddy very capable with arduino, raspberry pi, etc...

piggy back because i'm keeping the stock harness in case i wish to reverse.. i would just need to reconnect (with quick connects) about 13 plugs (air, coolant temp, tps, fuel injectors, coil/spark plug wires, crank, cam, and o2... )
my goal: a couple, to learn how to use a stand alone, coil on plug vs the igniter, coil, points setup, bypass the afm - interesting that my 1991 964 c2 has the very same elements and it'd be cool to bypass same. the option of forced induction or engine swap could be in the future... watched a video on youtube on a k24 swap with 6 speed tsx transmission with slight mods to shorten the drive shafts... oh, and possible to turbo the 4age
 

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Discussion Starter · #7 ·
I strongly suggest against working in a "piggy back" fashion, and instead replacing the OEM ECU. Splicing into the OEM harness, and especially sensors, is problematic. You can, instead, build a patch harness, or a PCB which plugs in place of the OEM ECU.

The Speeduino project is fantastic, as far as a project goes. Their automated hardware-in-the-loop unit testing is really cool.
It is, however, still lacking on some features I've found necessary in other applications. Not sure if the same problems would pop up with the AW11 or not, but I ended up going with a microsquirt module for that application and found it to be very robust.

DIYAutoTune has a product called the DIYPNP. They used to have a version for the AW11, but the connectors are no longer available, so they discontinued it. You can still buy a DIYPNP from DIYAutoTune and make the board for the AW11 by cannibalizing a connector from another ECU, or try to find an older DIYPNP. You can use their base tune as a starting point, too.

You can, of course, build a similar patch harness or PCB for the Speeduino if you wish.

We don't have points on the AW11. The ignition timing is digitally controlled. CoP doesn't really offer much of an advantage for 4A-GEs until you get WAY up in the RPMs or WAY up in the boost. Your efforts would be better spent working on driving behavior, start, idle, acceleration enrichment, etc. Make it work well. Then decide what needs to be improved.
I strongly suggest against working in a "piggy back" fashion, and instead replacing the OEM ECU. Splicing into the OEM harness, and especially sensors, is problematic. You can, instead, build a patch harness, or a PCB which plugs in place of the OEM ECU.

The Speeduino project is fantastic, as far as a project goes. Their automated hardware-in-the-loop unit testing is really cool.
It is, however, still lacking on some features I've found necessary in other applications. Not sure if the same problems would pop up with the AW11 or not, but I ended up going with a microsquirt module for that application and found it to be very robust.

DIYAutoTune has a product called the DIYPNP. They used to have a version for the AW11, but the connectors are no longer available, so they discontinued it. You can still buy a DIYPNP from DIYAutoTune and make the board for the AW11 by cannibalizing a connector from another ECU, or try to find an older DIYPNP. You can use their base tune as a starting point, too.

You can, of course, build a similar patch harness or PCB for the Speeduino if you wish.

We don't have points on the AW11. The ignition timing is digitally controlled. CoP doesn't really offer much of an advantage for 4A-GEs until you get WAY up in the RPMs or WAY up in the boost. Your efforts would be better spent working on driving behavior, start, idle, acceleration enrichment, etc. Make it work well. Then decide what needs to be improved.
Got your message and thanks for reaching out. Good to learn from others experience.

I'm quite well down the road with the existing speeduino setup and hope it works.

One of the main reasons that I didn't explain about my mr2 is that the main harness is quite hard and brittle and i've had issues with several of the pins on the harness connection to the ECU.
My Mr2 was sidelined for months while racking our brains for months with 'cranks, no start - turns over and won't idle'. and ended up being five different issues: igniter died and replaced with a 33 year old igniter. signal wires coming out of the crank and cam very stiff, pins in the harness going to ECU not 'spreading' out and staying in place... and E01/E02 wires would slip out of harness, and required repair.

And someone had been in the harness cutting in and bypass 'something'. This after having the harness spread out on the ping pong table in the basement in the winter going over each and every contact and connection.. so frustrating...
That said I'm hoping the speeduino can run the same as the stock ECU and not expecting any improvements other than perhaps a slightly more responsive throttle due to afm bypass. Then I have real issues to deal with... smoke show which will be engine out rebuild... or head rebuild and replace.
 

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Discussion Starter · #9 ·
Yes, let's not call it a piggy back. I think i could disconnect the ECU and the car would run (fingers crossed). I am leaving main harness in place and as I write the message, I'm thinking, i could remove completely. Only have the oil pressure gauge still connected.

Question about the throttle position sensor: I've run the VTA, E2, IDL to the ECU. Though there is no place for the VCC. From the schematic, It shows the E2 is a BR wire that connects to the coolant temp sensor and then to E21 and ECU? Can i bypass this? And what does it do to the quality of the idle when engine is cold vs operating temp?


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Discussion Starter · #12 ·
Thank you B!

I have the E2 as 'sensor ground'. E21 also called 'sensor' ground... . I have the IDL going into the speeduino idle... vta going into speeduino TPS signal and VCC going into +5V called VDDA in speeduino ...

Getting the correct Ohm readings now. Corresponds with the opening and closing of the Throttle...
 

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Discussion Starter · #14 ·
Better off to get a Megasquirt. The speedduino is still a piggyback.

It would be better, if you have to go piggyback, to get the JDM or Euro MAP eletronics and tap in an e-manage.
don't know what any of that means and will do some research on the jdm/euro MAP and 'e-manage'... is that vs the tuner studio or more about the fuel maps for the jdm vs USA? thanks!
 

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Discussion Starter · #17 ·
I have a feeling that the IDL contact in the TPS and the idle pin in the speeduino aren't related.

The IDL contact in the TPS tells the factory ecu when the throttle is closed so that it knows when to cut fuel on over run. It might have a different operating regime (not sure on that one).

The idle channel in the speeduino is there to drive an idle control valve, which the 4age doesn't have (or need).

Webbixman is mistaken, the current versions on speeduino are stand alone systems. Don't worry about learning about other forms of the factory ecu or e-manage unless you really want to 😉.
I calibrated the throttle position sensor, it is accurate and 'knows' when throttle is 0-100%...

I'll do a little more reading on the idle... some cars have the idle air control valve (like all my german cars have that expensive t-shaped unit made by bosch typically),

thanks for clearing the question about e-manage.
 

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Discussion Starter · #18 ·
i do have question about crank and cam signal. i have cut into the distributor and taken the crank and cam signal - and adjusted the tuner studio to read the distributor (vs trigger with missing tooth etc) and cannot get a engine speed (rpm) on the tuner studio.

also reading the speeduino manual, the ecu fires the coil on plug... 1,2,3,4 so need to adjust the accordingly... firing order is 1,3,4,2

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Discussion Starter · #22 ·
has anyone taken a distributor and converted the signal (balanced signal) to an unbalanced signal. Need reference to ground to get the square wave typical of crank triggers... need crank and might get a way with no cam signal?
 
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