shifty35

Hey everyone! Just some quick questions regarding selecting a flavor of MS for me.

Current setup:

94 1.8L in a 90 shell, running on a 1.6L ECU with 1.8L injectors and an RX7 AFM. Sucks. Big Time.

Throttle response is pitiful at low rpm - I chalk this up to no TPS / batch injection. ECU can't hope to respond to rapid throttle change.

Plans are to ultimately build a CSP engine, probably a VVT engine. Not concerned with controlling VVT at the moment though. I'll probably want to be running sequential injection, and I have a 94 throttle body with a linear TPS I'll be using.

As for my level of experience, I've owned two turbo Hondas and tuned many more on Crome, and even Uberdata back in the day for any familiar.

I also have a Master's in Electrical Engineering, though my focus is more on the side of programming / microcontroller design than actual electronics work.

I've socketed at least a hundred Honda ECUs, so my soldering skills are above average at least. I would definitely be comfortable putting together a full 3.0 board if that was the best option.

That said, trying to decide which MS flavor is the best bet right now. I'm leaning towards a DIYPNP, because it looks like it is the simplest out of the box - all the MS2 / 3.0 board kits seem to need a lot of extra hacking / jumpering to work with the Miata. I'm comfortable doing this, but it just seems like it's all there already in the DIYPNP.

curly

iTrader: (25)

There is a base board for all Megasquirts, with modifications required to run a Miata engine. I wouldn't call it hacking/jumpering.

But yes, the MSPNP (not to be confused with DIYPNP) is the cleanest, easiest method. It is also about $450 more than you need to spend. the DIYPNP is a base megasquirt board that's already soldered together, I think. You'd still need to "hack/jumper" the miata mods onto it. I think.

Everything you need to run MS would cost you ~$300, vs the $750 or whatever the MSPNP costs.

Don't quote me on any of this, do a little more research for yourself.

Braineack

iTrader: (62)

> MS-I or bust.

shifty35

This was definitely my original plan, but I'd like to be able to go to NB sensors at some point. From what I can tell, you need MS2 for that.

Full sequential injection is another "do want", and it looks like some wiring hacks are needed for that on the MS2.

Ben

iTrader: (33)

I think a DIYPNP with a sequential upgrade card would be right up your alley.
Pros:
Inexpensive
Easy
Plug and Play
Powerful
In stock

Cons:
Probably will not get VVT control

Note: We are working on releasing a standalone VVT controller that would interface to this box.

If you're up to some arm twistin', a V3.57 MS3X (v3.57 board, MS3 processor and MS3 Expander) would also be pretty easy. The only circuit you would need to build would be the crank input. The cam input, ignition outputs, idle valve, boost solenoid, tach output, and pretty much anything else you can think of is already taken care of.

Pros:
Easy
Exceptionally powerful

Cons:
A bit more expensive
Limited availability
Not plug and play

Note: You can make this plug and play if you add a pigtail harness and a DIYBOB.

CoralDoc

It's odd that your car isn't running better with the OEM induction. My '93 with '00 engine transplant ran quite well with the 1.6 liter ECU and AFM, though I did swap in some '95 injectors.

That said, the car ran much better when I swapped to a 9093MSPnP. It's still in the car, though I've added forced induction.

shifty35

I don't know that it runs bad - just from my experience tuning cars, I know there is a lot left on the table in the tune alone. That bothers me.

CoralDoc

True, that. I picked up 5-7rwhp and some usable mid-range torque when I went with the Megasquirt. Here's a link to a thread I started on M.net when the car was normally aspirated on tuning the transplant: http://forum.miata.net/vb/showthread...=engine+tuning