Howdy folks my accocunt that I made like forever years ago got deactivated from not being used so I am chained to the newcomers forums for a while.

Long time rotary owner starting with an RX3 back in 1985 and continuing to every rotary powered car except these models: late 60's cosmo sports, 70's rotary familia, and the RX-8. I considered getting one but ended up keeping my FD at the time.

I have been wrangled into a project by a friend, or an idiot depending upon how you look at him as he knows nothing about rotaries. he does have me available for abuse though (so who is the actual idiot here?)

so i am trying to research stand alone ECU... the engine/manual trans will go into a mid 80's 3 series BMW so none of the drive by wire for the engine is needed (or wanted) we can change out throttle body if needed other wise we will just modify the stock throttle body. would be nice if it could output the basics like temps and possibly turn the cooling fans on and off but not required.

any suggestions on a good ECU that is well suited to the 13b MSP? hopefully it is laptop programmable and would come with a base tune for a stock engine to begin with. Price is not so much a concern with my special needs friend.

thanks

Ken

@Jedi54 please move to whatever forum you think is best suited for this question, Onegai Shimasu!

 

Kenn, this sounds like a super interesting project.
hopefully some of our members will come along with some advice for an EMS.

 

Honestly, my first thought is a Haltech rotary-friendly ECU. Something basic and not car specific like how the MightyCarMod guys like to use in some of their car builds.

The question is which would be better for OP's goal, a generic rotary one (havent looked into those, might be tricky to make work with some 13b-MSP things like the auxiliary port valves and secondary shutter valve, can premix to ignore OMP)

or a Rx8 specific one (for sure has everything needed for the motor and all its valves and everything, probably would work without worrying about the ABS or power steering, not sure if you could use something besides a Rx8 instrument cluster or throttle body/pedal for DBW.)

 

was hoping to be able to use the aux ports and the shutter valve and the OMP. it seemed like 10 years ago or so there were a bunch of ECu's that folks were using but I fell away from rotaries for a while and i finished my tuning on my seven over a decade ago and have not touched it since then (currently parked awaiting restoration) My friend is a bit of a knuckle head and sprang this on me out of the blue, no offense but the first words out fo my mouth were that a 13bT would be much mcuh simpler but he had already bought the engine, transmission and the ECU. but without the rest of the modules and the go pedal I knew it was going to be a PITA.

well thats why we play with things I guess. if the MSP engine had more value here in Japan I would still tell him to sell it, keep the tranny and just go with a 13bt or REW as those I am fairly competent on.

Ken

 

The stock ecu is fine to use in another chassis for as long as you keep the keyless unit and ignition switch/coil along with it. But most won't even bother to consider this...

 

so if he had the wiring harness, the pushbutton start and fob it oculd be run without the modules for all the other things? it would still need the acel pedal though for actuation of the throttle body.

i guess if thats the best option, what all parts are absolutely required?
engine
ECU
entire wireing harness
push button and fob
acell pedal assembly
clutch switch (or does the RX-8 have a neutral switch?
?
?
?