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: Fast Response GM Intake Air Temperature Sensor IAT/MAT/ACT Kit 25036751 25037225 | eBay
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: 18 AWG TXL HIGH TEMP AUTOMOTIVE POWER WIRE 16 STRIPE COLORS 5 FT EA PRD | eBay

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.

Google drive with my tune files can be found here: Speeduino Tune Files - Google Drive

This will be updated as I improve on the tune. My main mods are AEM intake, 2.5" j pipe back exhaust, FMIC, and a VICS, VTCS gutted intake manifold. Stock injectors, Stock Fuel Pump, stock turbo at 6 psi boost right now. It already pulls harder than the factory ecu with SSAFC at 9psi.
 

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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
 
that’s very helpful, i’m getting my block back from the shop maybe i’ll try setting up the fuel gauge with my speeduino, im doing a digital dash with an old android tablet
 
Nice, I heard people using those or a raspberry pi and run tuner studio straight from the tablet itself so cool of a feature.
 
I'm still dialing in the tune a little bit at a time, but the Speeduino hasn't skipped a beat. I'm currently running low boost at 6PSI holding a steady 11.8-12AFR in boost and it feels solid. I'm getting ready to bump the boost up to 9psi soon, but have been monitoring for detonation just to be safe as we know how fragile the FS-DET is. I put together a headphone based knock monitor that works very well once you know what detonation sounds like.

Details on how to put it together can be found here: DIY - Independent Knock Feedback (Knock Ears)

Parts list is as follows:
Knock Sensor: https://www.amazon.com/dp/ (commissions earned)

Aux Cord: https://www.amazon.com/dp/ (commissions earned)

Headphone Amp: https://www.amazon.com/dp/ (commissions earned)

Thread adapters: https://www.amazon.com/dp/ (commissions earned) you will need one of these and an 8mmx1.25 appropriate length bolt or stud to fit the Bosch knock sensor in the factory location.

Bosch EV1 Harness Plug: https://www.amazon.com/dp/ (commissions earned) you really only need 1 but it isn't very cost effective to buy 1 vs. an 8 pack.

Add your preferred set of ear plugs or headphones, something that blocks out some environmental noise will obviously work better. Bluetooth is not recommended as there is a lot of latency.

A little tip with Datalogging in Tunerstudio is that you can press the spacebar on the laptop and create a "mark" in your datalog. I'm able to do this in any event where I heard some DET, and was able to successfully back off timing on that cell.
 

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Still running strong on the Speeduino, I've upgraded the injectors to WRX 440's and switched to sequential injection mode (using a 99-02 626 camshaft gear). I'm in the middle of re-tuning my VE table for the new injectors, then the boost is going to get turned up to 9-10 PSI.
 
my speeduino is barely hanging on, i’ve required the car multiple times, still getting misfires and unexpected afrs, maybe i just need a professional tune? i can’t figure it out. it drives but barely and it’ll sometimes just backfire instead of making any power. any ideas? i don’t even know where to look. i’ve replaced everything including the speeduino, wiring harness, ecu, all fuses are good, made new tunes. it won’t stop misfiring and it won’t make enough power to go up a hill without my emergency lights on.
 
my speeduino is barely hanging on, i’ve required the car multiple times, still getting misfires and unexpected afrs, maybe i just need a professional tune? i can’t figure it out. it drives but barely and it’ll sometimes just backfire instead of making any power. any ideas? i don’t even know where to look. i’ve replaced everything including the speeduino, wiring harness, ecu, all fuses are good, made new tunes. it won’t stop misfiring and it won’t make enough power to go up a hill without my emergency lights on.
what does your tune look like? You can send it to me and I can take a glance at it when I have a moment. Also, did you run a datalog and check for sync loss?
 
definitely sync loss, all the sensors are just all over the place, tps,clt,mat,map, rpms are the most stable but theres still sync loss and some spikes. eve 12v is jumping around. but still, why? ive used different speeduino boards, arduinos, i have the ua4c, my temp sensors are shared between the ecu and speeduino. where should i look for this issue? wiring? its almost like the power source for it is all over the place, or a bad ground? ive checked up on my grounds and they all seem okay. if you still want to see my tune its possible it could be that too, but i think its wiring after looking at the log, my tune is pretty crap but it should at least be stable crap, not unpredictable.
 
definitely sync loss, all the sensors are just all over the place, tps,clt,mat,map, rpms are the most stable but theres still sync loss and some spikes. eve 12v is jumping around. but still, why? ive used different speeduino boards, arduinos, i have the ua4c, my temp sensors are shared between the ecu and speeduino. where should i look for this issue? wiring? its almost like the power source for it is all over the place, or a bad ground? ive checked up on my grounds and they all seem okay. if you still want to see my tune its possible it could be that too, but i think its wiring after looking at the log, my tune is pretty crap but it should at least be stable crap, not unpredictable.
Send me the log and the tune, 12v jumping around could happen if your idle is jumping around and the alternator is varying it's charge, but it could also be the ground. I would verify voltage at the battery with a multi meter and see if it's also jumping around there. PM me and I'll send you my email address to send the tune and datalog over. I would also advise against sharing CLT and IAT with the factory ecu, when they're shared the resistance on them is changed and are probably sending inaccurate data to both the factory ECU and the Speeduino. Plus the factory IAT is very slow reacting compared the the proper GM IAT which has near instant response to temp changes.
 
okay, i’ll hop on my computer and grab some of those files, and yeah i think having separate temp sensors is probably pretty smart. i just didn’t want to tap into my thermostat housing. also the battery voltage is jumpy even with the engine off and it seems to be affecting all the sensors too, it’ll vary +-2v over the course of a second or two. i’ll probably order my own temp sensors today.
 
The battery voltage swing is going to have a huge effect on how the car runs, especially if you don't have the injector dead times 100% perfect. The speeduino will be dramatically adjusting the fueling to match the voltage change. Definitely sounds like a ground issue, check the battery terminal ground and run dedicated grounds from the speeduino to the battery ground or the engine block.

For the Coolant temp sensor, I used an inline hose adapter and just drilled and tapped it to accommodate the CLT sensor, I have links to everything you need in the top post of this thread.
 
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