MS1 or MS2 on a 90-93?
 

Friend of mine asked me to build a MS for his 90-93. There's a pretty standard begi kit on it, no boost control or anything.
I was thinking of getting a MS1 or would there be advantages on using MS2?

For an NA, and especially a 1.6, the featureset differences are fairly small. The MS2 does offer a higher resolution in the fuel calculation, which can be helpful if you plan to pass an emissions test while running larger-than-stock injectors.

Its mode advances features will not be of much use to you. Running fully-sequential injector drive, for instance, would be great for a '94+ car. On your friend's '90-'93, he'd need to run a whole new fuel injection harness to take advantage of that.

The MS1, while not sexy and new, gets the job done.

I currently have a 90 miata with ms2 up and running. It was alot of extra research for the 90-93 because most people just use the ms1 on those years. I had to take what was already figured out 100% for the ms1 and try to adapt it to the ms2. But if you do need to know how to install a ms2 let me know.

Sorry to disagree wtih Joe, but I feel that MS2 does offer enough differences in featureset and resolution to make it a worthwhile upgrade. I did not feel this way before I played with the software. As a bonus, it is a cheap upgrade (less than $100).

You don't have to run a 'whole new harness' for full sequential fueling; you just need to run 2 additional wires. This is worth 1-2 mpg. And you can still run seq spark too, which is awesome for when you go to better coils.

You should do a little write-up.

you mean like this:

http://www.boostedmiata.com/gallery2...serialNumber=2

http://www.boostedmiata.com/gallery2...serialNumber=2


it can also be found here: http://msextra.com/doc/ms2extra/MS2-Extra_4g63.htm

Yes, like that. Easy enough.

From that I took the DIYPNP basemap for the 1.8L (2.1.1b) and scaled the req_fuel and made other small changes.

I'll have my own MS upgraded by the end of the week, I have a board modded and my MSI msq converted, I just need to acquire the CPU this week. I'm still going to run parallel because I'm too lazy to build a standalone harness...well, i just ran out of 64-pin connectors and don't feel like ordering any. But really, I'm just letting the OEM ECU run idle, so whatever.

If you notice on my pictures I decided to use the traditional 2nd trigger input like we do on the MSI boards, not the optisolator circuit. You will also notice I put the .1uF cap on the daughterboard itself. There is an inline 1K current limiting resistor on the board (D9), so the cap needs to be after it. But both trigger inputs are simply 470ohm pulls-ups for each trigger.

Cool. I tried to attach my .msq here, but I am short on storage space (already 20mb over limit). Think you could increase my limit?

PS, I just gave away (2) extra 64 pin headers that I got from online components to fluff out their minimum order requirements. Sorry, you should have said something a few days ago.

did that work?

It's okay, I'll order some when I build another MS for someone. I just hate to order a min of 5 connectors and spend $40 just to sit on them for a while, I usually order 10 or so when I run out. I really have no problems with my parallel setup otherwise. I do want to mod it to run the fuel pump ground back through the AFM harness through something and then jump the connector back to the relay.

Yes, thank you.

whoops, i need to d/l 3.0a

edit: sweet, i love seeing the 16x16 fuel maps... i plan on keeping the same amount of boost rows i have now, and get the added resolution in the cruising cells where it's finicky now.

I went with MS2 on my '90 for sequential fuel and more I/O. If you're only going to build it like the MS1, it'll still give more resolution in the fuel calculations, but you're not really taking full advantage of the CPU. If he doesn't plan on upgrading anything and not using EBC or PWM idle, then it may not be worth the extra $90, but if you or he adds some of the extra goodies, it is.

What I have is:
sequential injection using the peak and hold driver board
wasted spark
2nd trigger input
closed loop PWM idle with upconverter board
fan control
knock sensing
baro correction
launch control
closed loop EBC
table switching off WI switch

I really don't feel like rewiring the injector harness for sequential injection, maybe down the road if I feel like another project. Otherwise I mainly wanted to upgrade for the EBC code.

Regardless, the CPU speed in itself should prove better on it's own. 16-bit 24Mhz vs. 8-bit 8 Mhz CPU, 100 times more fuel resolution, potential MSIII upgrade, can read up to 257*F, etc...

sorry im an MS noob... can ms1 be made to run sequential or as that a no-go

No, mainly because there are no spare outputs.

Is that my MSII brain?

correct. It's in the mail btw.

what's the cap for? First time I see it mentioned.

Filters the 2nd trigger, needed with particular input, especially when we were running MS-I/HR, I believe the optisolator circuit uses a .01uF filter. The absence of this cap is part of what delayed the MSPNP9697 from getting on the market.