MSv3.0 sub-circuit documentation
 

Hey guys,
I'm starting up my assembly of my MS3x, and have been trying to gather as much info as possible.
I understand that the base v3.0 board is only responsible for a few of the basics: +5v/+12v, fuel pump, air/coolant temp sensors, o2 sensor, tps/crank sensors (at least for NB1 applications).

What I was wondering is: Does documentation exist that details the assembly of the individual circuits responsible for these things? I've been looking at Westfield's website for additional guidance, but I understand some of the info is a bit out of date (for example, it has a list of diodes to install which based on this thread aren't necessary: https://www.miataturbo.net/megasquir...-wiring-85654/ ).

I think it'd be most clear for me (and maybe others) to be able to build each individual sub-circuit in a "Step 1: Build TPS circuit which consists of parts X, Y, Z" manner.
Right now most write-ups, while helpful, simply have a list of instructions such as "Install all parts of type A, install all parts of type B, etc" which is probably easiest for speed of assembly, but difficult for actual understanding.

I've read the official doc at: http://www.msextra.com/doc/pdf/MS3XV30_Hardware-1.4.pdf many times now, it does have Appendix C, which is helpful, but of course not Miata specific (it suggests assembling the entire v3.0 board, which is un-necessary for our uses). I thought awhile back I had seen something similar to what I'm looking for (how to assemble just the power circuit for instance), but if it actually exists I can't seem to locate it.

Maybe my thinking is flawed somehow in how the v3.0 board works, if so please set me straight!

Is this what you are looking for, at the bottom of this page?
V3 Main Board

V3 Main Board

I'm not sure if the MS3 V3.0 board is exactly the same as the MS2 V3.0 board, but here's schematics.

Really just follow the Westfield guide, then perform the voltage checks in the Hardware manual. I don't see any reason to assemble each circuit at a time.

Not clear what exactly you're looking for.

Every circuit you need is already pre-populated on the mainboard or Expander board.

if you're building circuits in your MS3x, you're doing it wrong.


In going to quote myself from the linked thread above:

That's the only mods you need to make other than populating the mainboard.

The schematics of the v3 mainboard are all available and somewhat easy to read.

Find component listed in the westfield guide, look in schematic for which circuit it is part of.

All the ms3x schematics were scanned by a potato. And borderline unusable.

Thanks guys,
I guess to say more clearly what I was wondering:
Input 20 (on the attached file) handles the AIT input.
Is there documentation that shows the sub-circuit (with components) that handles the input for pin 20 (or any of the other ones)?

What's driving me to wonder, is it'd be interesting to see the circuits with/without the diodes listed on the Westfield guide. It's mostly for my own understanding of things, than for the actual assembly (which I understand is possible to just follow the provided manual, if you don't mind having all the extra un-used components on the board) other than the handful of mods listed by Brain in the previous post.

Yes. The schematics. As mentioned earlier

MS3baseV30_Hardware-1.4 page 176

AIT is on the second page

Attachment 176902

Okay, I think I'm following. So for the AIT, if I'm reading it correctly here, there's R4, R5, C4, C5, and it feeds into AD1-1?

If that's correct, then it looks like I just didn't do a good enough job reading through the docs.

Yes. Moar reading.

Nice! Okay, I think that's enough to be able to figure out the inputs/outputs. Teach a man to fish & all that.

Thanks for pointing out the obvious guys.

Dont do all the stupid diodes like in his writeup.

He had you add them because the on-board flyback for all PWM driven components via the expander board, because they were flawed. So Frank was adding in a diode back to 12v on each component, you do not need to do this and just add 12v to all the diodes on the expander board through (1) single wire.

Can you use a Nitrous output for the NB alternator control with a 1k pull up to 5V?

Nitrous out is the same kind of output as VVT. See this diagram. They are both medium current outputs.

https://cimg0.ibsrv.net/gimg/www.mia...0b2f1ff2ff.png

Should you have taken to time to actually read my instructions, you would have noticed that they have been updated a while back. Like to be spoon fed?

Yes, The main thing you have to watch for are the two banks of PWM out frequencies. IIRC -- it's been a while -- VVT and Idle are on the same bank, so I never use VVT out for controlling VVT, but use one of the Nitrous Outs, so I can select the more appropriate Hz for it, as well as one for the idle valve.

From my instructions:
"In case you’re wondering why I’m not using VVT but Nitrous2 to control VVT, this is because there’s only two different concurrent frequencies allowed across all PWM outputs. The outputs are grouped like this:

Group A -------------------------- Group B
PP0 – Inj 1 (mainboard) ----- PP2 – Idle
PP1 – Inj 2 (mainboard) ----- PP3 – Boost
PP4 – Nitrous 1 ---------------- PP6 – VVT
PP5 – Nitrous 2 ---------------- PP7 – FIDLE (mainboard)

What this sharing means is that Idle and VVT must use the same frequency. By moving VVT to an output of group A, this allows for a different frequency."

Thanks, Frank!

Thanks for the info. Does the alternator control pin require a frequency that matches better with the Idle frequency or with the VVT frequency? Basically should I put the idle output pin in the group A or group B PWM's

No problems using this combo:
Idle on Idle
VVT on Nitrous (1 or 2) out
Alternator on VVT
Boost on Boost

I dont try to deviate much from that so all the random maps out there are somewhat standardized.