So I'm planning on using an MS3X on my FD with a single turbo. Looking around the internet, I'm not seeing a lot of people who have done the same thing. My initial question is, why not?

There are obviously a few challenges with the FD that aren't difficult on an FC:

- Electric OMP control: Not supported by Megasquirt currently. To get around this, I built an Arduino to control the stepper motor in the OMP, and the MS3X controls the Arduino with a PWM signal.

- Tach output: Since the FD's tach is driven by the ECU instead of the trailing coils, it's one extra thing to do. From reading the Haltech forum, it doesn't seem like it will be too difficult; just have to figure out the proper settings.

- I'm not sure if the stock FD coils are easily controlled, but I'm planning on using IGN-1A's (AEM smart coils).

- The stock trigger wheel + mag sensors seem like they could be read as easy as the FC CAS, but I'll probably use an FFE wheel to simplify things.

Is there anything else I'm missing here? Any other road blocks?

 

fc or fd its basically the same thing.

 

I was wondering the same thing since I out a FMII kit on my miata. It worked real well. And coming to the rx7 less people use ms3 which is quite manageable.

 

Just make sure someone with in driving range can and will tune a megasquirt ecu... Im outta luck closest rotary tuner is 4hours away and he wont touch megasquirt...

 

Where are you located

 

far away lol.... Canada to be e xact

 

Well, one of the reasons I want to stick with Megasquirt is that it's so easy to tune myself. On my FC, it took me all of 2 hours to go from a sputtering, black smoke rolling VE map to a perfect tune (thank god for VE analyzer).

Maybe this is why the typical FD owner shys away from megasquirt? Most people just want to pay someone to tune their Haltech for them.

 

Not sure, i just wanted reassurance from a reputable tuner to make sure im not going to blow my car up. And now im stuck with with learning and tuning as i go.

 

alot of tuners don't want to tune the older self built units as there can be quality issues with the persons ability to solder etc. if you buy a the ms3/ms3x with the 3.57board or the ms3pro there is no reason for them not to tune it. if you know how to tune rotarys and competent with haltecs and links/vipecs you can tune a megasquirt. tuner studio is very comprehensive IMO and is only slightly different layouts as the other ecus.

 

Really no reason not to use a Megasquirt on an FD. Just in the FD world, they seem to only use a specific set of standalones. Probably traditionally because the majority of support, many years back, came from only a few vendors.

 

Alright, I've made good progress. My car is running great; I've got a working tach, good idle control, logging VSS, TPS, etc. I'm currently premixing, I haven't gotten the OMP up and running yet (but it's still not supported by megasquirt). I'll share some info from my build for future reference.

What's needed from the stock FD harness:
This is a good reference, through step 11: Haltech E6K Installation

All you need are the 4 plugs that go to the transmission. Trace the wires from these plugs back to ECU side of the harness (white and blue plugs), keep all of these wires intact. The black wire in step 9 of the above link, on the lower left of the white plug; this is the ground for the dash. Cut this wire out of the stock harness, leaving plenty of length connected to the white plug. All of the other wires on the white and blue plugs that don't go to the transmission can be cut off. Plug the 4 plugs into the transmission and the blue and white plugs back into the passenger footwell. Ground the black wire to the chassis. Your speedo will work now.

Stock Tach
Find the yellow plugs for the stock ECU. On the smaller of these two yellow plugs, there is a yellow wire with a blue stripe. Cut this wire and connect it to the tacho out wire from the Megasquirt. Proper "Tacho output" settings in Tunerstudio are "Fixed" and "Normal" speed. Your tach should work now.

VSS
Conveniently, the stock dash outputs a 0-5V digital signal to the stock ECU for VSS. This wire is on the large yellow stock ECU plug, and it's a green wire with a red stripe. I connected the "datalog in" wire from the Megasquirt to this wire. I read somewhere online that it was an 8202 pulse per mile output, but my speed was cut in half. I changed it to 4101 pulses per mile and it read spot on. I'll eventually use this for launch control and boost by gear.

Idle
The idle valve is similar to the FC BAC. 2-wire PWM, polarity doesn't matter. I have it set at 204hz in "Normal" valve mode, and it works perfectly.

Other notes
- IGN-1A coils are awesome, just make sure they're wired properly. FrontL-A, RearL-B, FrontT-C, RearT-D.
- I'm using the 36-1 FFE trigger wheel with hall sensor. It's been rock solid since the first crank. I think hall is worth the extra price over mag just for the peace of mind.
- I'm using an $18 150psi pressure transducer from ebay for fuel pressure, and it works great.
- The MS3X is mounted in the stock ECU location with a bracket I made. The stock plastic interior panel fits over it.
- I have a speed sensor on my EFR, reading the output of that with the Megasquirt (PT4 wire). # of teeth has to be set to 1.75 (14 blades on the compressor, and the speed sensor divides the input by 8).
- MSdroid is AWESOME! I have a Nexus 7 that I mounted where the stock radio goes. It displays everything you want, and it will log to an MSL just like a laptop will. I rooted the Nexus 7 with Cyanogenmod 10.1 USB ROM (has a hack that allows fast charging with an USB otg y cable). So when I turn the car on, the tablet turns on automatically and charges while displaying. Turn the car off, and it goes into deep sleep.

Overall, I don't see any reason to use a different ECU over the Megasquirt, unless you absolutely need OMP control. What I have is proving to be a really solid setup.

 

Great results!
You've added just about every feature I'm planning on using. Glad to hear everything's working well.
Have you considered adding a second VSS? I've heard great things about MS3s traction control setup. I plan on adding it when I finish my wiring this spring.
MsDroid is so great. I went months without connecting my laptop because it made it so easy to datalog and load new tunes

 

Yeah I've thought about adding a second VSS. It's definitely more difficult though, I don't think there's a "digital" signal anywhere from the front ABS sensors, I'm pretty sure all of the wires I could tap into would be low voltage signals. So, it's still do-able, would just have to build/buy an ADC.

But, yeah, traction control would be awesome.

 

awesome. loving all the ms3 stuff filtering through. I'm just saving for last of my loom materials(dr25 etc is pricey) then will be doing the same with my nexus tablet. I'm running the CAN egt setup, flex fuel and the 4bar map sensor & efr9180.should be good for it
these posts lately help with motivation