Guide Run your Mazdaspeed Protege on a Speeduino

I'm going to build out this Thread with details on how to use a Speeduino to run the MSP in a piggyback Configuration. This is a great affordable unit for anyone who is capable of doing minor soldering and crimping of some wiring. The Speeduino will be have full control of Fuel and ignition, and the stock ecu will keep control of idle, AC, alternator charging etc. As of this weekend 3/16/24 I have successfully managed to get my MSP starting and idling with the Speeduino unit installed.

The Speeduino unit I installed was a unit from Openlogic EMS and can be purchased here:

Because our cam and crank sensors are VR style you will also need a VR conditioner for the unit:

If you're not comfortable with some minor soldering of some through hole PCB components, you can get a ready to go unit that contains the VR conditioner and a 2ft pre-crimped harness for approx $300 here: Fishdog (UA4C Seawolf) Speeduino ECU.

The only thing you would need to do on this unit is set the jumpers for VR on the board and do some wiring into the factory ecu harness.

Additional Parts that you will need for install:
GM IAT sensor and pigtail: https://www.ebay.com (commissions earned)
GM Coolant temp sensor and pigtail: https://www.amazon.com/dp/ (commissions earned)
Coolant temp sensor housing: https://www.amazon.com/dp/ (commissions earned) (this comes with 1/8 npt thread, but can easily be drilled and tapped to 12mm x 1.5 thread to accept the GM coolant temp sensor.
A spool of automotive grade wiring for building your harness: https://www.ebay.com (commissions earned)

Attached at the bottom is a PDF of the Pinouts for the Detonation EMSx4 unit and what corresponding pin number of the stock ECU they get wired to. The pin numbers are listed at the beginning and end of each row of the ecu plug, making it very easy to count forward or backward through the rows to find the pin number you need. Once I get a decent startup tune squared away I will post it up here also.
 

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i just finished installing mine into my p5! still trying to figure out some stuff but i’m happy that something so cheap and functional is on the market right now. i have an automatic so i have the ecu controlling the alternator transmission and the abs. everything else i’ve wired through the speeduino
 
i just finished installing mine into my p5! still trying to figure out some stuff but i’m happy that something so cheap and functional is on the market right now. i have an automatic so i have the ecu controlling the alternator transmission and the abs. everything else i’ve wired through the speeduino
Awesome, I have lots of Megasquirt 2 experience with the Turbo Miata I own. I'm thoroughly impressed with speeduino so far. I just got some issues with my wideband squared away, it wouldn't output 0-5v signal to the speeduino. I ended up replacing it with an AEM unit that i just got installed yesterday. I drove around for an hour yesterday tweaking the tune outside of boost. It feels great so far. I'll be adding some more details to this thread (including a decent starter tune for stock injectors) once I get all the kinks worked out.
 
great! there’s no engine in my car yet so i haven’t been able to chase down most of the problems im sure i’ll have, but for about $150 im really excited to be using it. i hope the ecu will still want to shift the transmission, but i cut just about every sensor off of the stock ecu save for tps, ckps, clt, and anything transmission related. the dash is lit up like a christmas tree and i have to pray the speeduino can control my tachometer, i cut the wire coming from the stock ecu and routed it to the speeduino. my fuel gauge isn’t showing anything either. if you have any tips on how you wired everything that would be awesome, like i said i dont know what problems i have yet but it’s about halfway functional from what i can see
 
never mind about the wiring, i didn’t notice the diagram you made. i wish i did it but just cutting and splicing. instead i just took the whole harness out of the car and removed 70% of it. i replaced half of the wires with my own and it took a week of 6 hour days to do the whole thing.
 

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never mind about the wiring, i didn’t notice the diagram you made. i wish i did it but just cutting and splicing. instead i just took the whole harness out of the car and removed 70% of it. i replaced half of the wires with my own and it took a week of 6 hour days to do the whole thing.
The factory ECU will still want to see all the inputs, and probably uses them to calculate shifting patterns. If you keep the ckps, cmps, iat, clt, and tps connected it should function normally. you can also just use the stock ecu output for the Tach. As far as your fuel gauge, I'm not sure. I don't think the factory ecu has any input for that, you may just need to connect the dots on the wiring for that.
 
i think my cluster might be screwed up, at least i have an ecu i can make any screen work as a cluster now!

i have all of those sensors daisy chained through my ecu, the outputs for it should just be the transmission the abs and maybe stuff like the a/c and some other small stuff
 
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