gap analysis between hellen72 and mazda speed miata

[rusefillc]

looks like mazdaspeed miata uses 72 pin connector and we kind of forgot about it?

https://github.com/rusefi/rusefi/wiki/Mazdaspeed-Miata-2005

[stefanst]

MSM (Mazdaspeed Miata) is a very small base. And they are the highest value ones, so not as many people mod them with aftermarket ECUs. Keeping them stock-ish is quite common. Demand will be very low. I am aware of, have seen and have built ECUs for dozens of NA/NB Miatas using aftermarket ECUs. But not a single MSM.
Not a lot of cars out there. Imho all other NA/NB Miatas should have higher priority.

I'll check on differences though.

[rusefillc]

I agree with you 200% but BeerMoneyRacing new miata guy of forum/slack gsays he has a MSM customer local to him @stefanst

[stefanst]

I see.

Quick difference report, based not on going through wiring diagrams pin-by-pin, but using other connection tables for MSM assembly yiel;d the following differences:

J2 - no differences
J3 - no differences
J4:
4D: STD: VVT 12V | MSM: n.c.
4N: STD: AIT | MSM: n.c.
4R: STD: VVT | MSM: AIT

So, first quick approximation seems to indicate a VERY simple mod, just moving AIT, might work. We have to confirm all the pins NOT used by MS3 before moving forward though.

[stefanst]

The above pinout seems correct. There is some indication that 4D may be boost control, but publicly available schematics are incorrect. Leaving 4D disconnected would be the safe thing to do until more information is available.
If we have an MSM car for testing, I recommend locating the boost control valve and testing if one pin from the valve goes to pin 4D and the other one to either GND or +12V. It may be getting +12V from the ECU, just like the VVT valve on the standard car.

[mck1117]

IIRC there's a boost control solenoid somewhere in lieu of VVT.

[BeerMoneyMotorsports]

we can make 4d vvt power OR boost control configurable as needed. it can also be isolated.

[BeerMoneyMotorsports]

https://docs.google.com/spreadsheets/d/1raHTEK5JAHUCpqOJ4ms5ALVBcwi8FxiH_gkN7S6F6c4/edit#gid=0