Hank

I am interested in possibly adding a megasquirt with a DIY turbo system to miata. From reading I have gathered that people use the MSI with the 3.0 deal on the miata. Is this correct? Also, what else will I need for the switch the megasquirt. Do I need to buy the wiring harness, or can make the stock harness work? Is the stimulator really helpful when building? What about sensors?

I have a lot more reading to do obviously, but I want to make sure I know what all I will need when the MS goes in, so that I can work out a budget. I am also planning on using the LC-1 wideband with the MS. Thanks for your help.

Aussie Driver

We all seem to be using the MS1 chip on the v3 board with MSnSE.

What you need to get MS running your car depends on what you want MS to do. Fuel is easy, fuel and ignition and idle control is a little more difficult. Check out our success stories for the finer details about what you need to modify on your board and what you need to do it.

If you're building your own MS then the stim is highly recommended. If you're buying a pre-built board then you won't need a stim.

I have spliced my MS into the OEM harness. Others have purchased a pre-built harness and connected it to the OEM connectors. The choice is yours, either option will work.

I would recommend that you get both the GM IAT and coolant sensors to use. You can stay with the OEM sensors but you will need to change the resistors on your board to match the different bias resistance.

Again, I would suggest that you read the different success stories here. You won't find as much info specifically relating to miatas anywhere else.

Good luck with the project and don't be shy about asking more questions.

Steve

Jefe

iTrader: (7)

3.0 board and MS I
Stim
Cable to connect to lap top from MS
GM AIT sensor
GM CLT sensor

One thing about using the Stock sensors and easytherm. The easytherm file does not fit on a 2.0 HD 3 1/2" floppy(@least for me), so if your using a $40.00 laptop, you might be limited...

I pretty much used 18 ga wire everywhere, I had enough left over from an EM install so they're all color coded. I did use 10Ga and some 12ga, but that was for my coil stuff...

You'll also need to consider a WBO2.

If your just going to control fuel you could just use the 2.2 board, Then add a Bipes for timing....

Hank

Well, I was planning on doing spark and fuel, but it seems that spark is major pain. I have a J&S ultrasafeguard, which I guess I could still use for timing and safety and just run fuel on the megasquirt. Does this sound like a good idea or would I be better off runnin spark off the MS as well?

Aussie Driver

I have not had a single problem running spark with my MS. Everything has worked perfectly with both fuel and spark on my new 1.8 engine from the word go.

Spark can be done, it has been done, and it was done with zero problems.

If you want to give it a go then there is no reason why you couldn't get your MS controlling spark too.

Hank

Sounds good. I guess I'll just go ahead go for both fuel and spark as planned. I guess that wasy i could sell the J&S and get a little more budget for the whole DIY system I would like to build

Is there any additional sensors or anything that will be needed to run spark as well as fuel. I am working out a budget for the MS and I need to EVERYTHING that I will need so there is no surprises. I already have soldering equipment and an antistatic ground strap and stuff from when I built our computer last year.

Hank

Also, what is the best way to handle the wiring situation. Do most of you guys buy the harness for like $68 for the MS and use that to wire into the factory harness.

And last questions about fueling. What type of injectors will I need? I am shooting for somewhere close to 200HP with my system. I believe 440's have been recommended, I just want to confirm this and get an estimate on how much I can expect to pay for the injectors. What about fuel pump? What are most of you running, and what will I need to feel the 440's or whatever.

Al Hounos

Do It the way Kags did it in his writeup. I'd do it that way and keep my $70 if i did it again. DSM 450s and rx7 4x0s are known to work well in a miata. expect to spend about $60, plus cleaning if you want. stock fuel pump is fine.

Hank

Great. Thanks again Al. I have a ton of reading to do obviously, but I getting the basics nailed down. Are DSM 450's a plug and play setup with the miata using the MS or will I need different connectors and things from the DSM car as well?

Anything else need for spark and fuel other then the two GM sensors.

Aussie Driver

You will need three 1K 1/4 w resistors and a bit of extra wire to be able to get the CAS input working, you will need some more wire to get the spark outputs working and you will need a TIP122 transistor to get the PWM idle control working. That's probably only another few dollars.

There are no big and expensive surprises unless you break something.

Jefe

iTrader: (7)

450's are not PnP.
But they do fit, @ least mine did...

Don't follow my lead and you won't break the bank(if there is a long or expensive way I will find it-- 2X that way....hahaha..)

A few years ago I went to crapshack and bought either 500 or or a thousand assorted resistors for 10 bucks, everyone I have ever need seems to be in that pile...