944 MicroSquirt Plug and Play Project

JustinL · 09-06-2007, 05:21 PM

Well after a grueling wait, microsquirt has finally been released and I was lucky enough to get in on the first batch of 10. For those who don't know about microsquirt, it's a miniaturized surface mount version of the Megasquirt 2 hardware. It comes in a sealed water tight case.

This project is an attempt to get a standalone ECU into the 944 market for around 500$. I'm going to be using a scrapped DME box to make a compatible plug for the microsquirt cable and re-use the stock wiring. I'm doing this so I can swap the stock computer back in in case of emergency, and when we do some back to back dyno comparisons.

I'll keep this thread updated with my notes so I can look back and keep a record.

ae1969 · 09-06-2007, 05:39 PM

...the holy grail has arrived.

I can't wait to play with it.

Nice and tiny. Slick.

many944s · 09-06-2007, 05:39 PM

Oooooo, now that is cute!
Definitely keep up with the updates.

fliphkd7 · 09-06-2007, 06:14 PM

YES! Finally!

blown 944 · 09-06-2007, 07:16 PM

I like the idea of the stock plug for comparison..

I tried as long as possible to avoid the standalone but it is looking like a necessity at this point

Thanks for the updates in advance

speedracing944 · speedracing944's Garage

WOW it is so tiny compared to the MSII. It looks to be 1/3 the size.

I would love a plug and play system for my '83.

Team this bad boy up with a plug and play "blown944 M90 supercharger" upgrade kit and us 944 owners will never be embarased by a mommy in a minivan ever again.

Speedy

fast924S · fast924S's Garage

That thing is sweeet. Always wanted a plug and play stand alone, Only thing is I dont have the time or money to dyno tune it

Schumi · 09-07-2007, 02:20 PM

Does the microsquirt have the ability to tune multiple O2 sensors? I have worked with MoTec's that have be able to tune each individual cylinder based on lambda from each of the 4 cyl's. It helps squeeze power from intakes and exhausts that arent perfectly optimized per cylinder.

Also, can it output a datastream or logging data on the fly?

Where do you get them? I haven't found a solid looking dealer online yet.

JustinL · 09-07-2007, 04:36 PM

I don't think the microsquirt can handle tuning 4 cylinders independantly because it only has two injector drivers. It does do logging and burst logging, but you need to have the laptop connected as it doesn't have onboard memmory for logging. I have always delt with DIYautotune.com. They are fantastic and ship stuff amazingly quickly.

Step one for next week will be to get the wideband, MAP, and IAT sensors installed.

Schumi · 09-07-2007, 04:47 PM

What type of MAP sensor are you going to use?

blown 944 · 09-07-2007, 08:31 PM

It looks like the GM 3bar MAP to me in the photo.

Zero10 · 09-07-2007, 11:03 PM

Will that work with the speed/reference sensors?

ae1969 · 09-08-2007, 07:58 AM

Quote:

Originally Posted by Zero10

Will that work with the speed/reference sensors?

That is the plan... It has an M+N trigger. So you have one that reads the flywheel and the other the reference sensor.
There are still a couple of smaller issues (rpm resolution when you do this etc).

You currently can use all the stock sensors, ISV and TPS with MS. All you need is to plumb an IAT.

This will be a plug and play solution for any 944. The possibilities are endless.

mfloren · 09-08-2007, 08:09 AM

id pick it up in a heart beat. call me when it is done. (unless it is about 5 months from now, at that time ill have a Motec880.)

719-534-3639.

JustinL · 09-08-2007, 10:14 AM

Quote:

Originally Posted by Schumi

What type of MAP sensor are you going to use?

Yup, GM 3 Bar is the one that I got. In case I ever want to boost to 30psi

It's actually the one recommended because it has to sit under the hood near the manifold.

The new beta code should be able to handle our speed and reference sensors.

Also our n/a throttle bodies don't have throttle position sensors, so we'll have to use x-tau for accel enrichment. With the MAP sensor so close to the manifold, it should be fast enough to have good throttle response.

Schumi · 09-08-2007, 12:43 PM

If not it couldn't be extremely tough to attach a TPS to the throttle cam...

sounds like a great project and an affordable performance boost for older NA cars. I would definitively install the system for 5-600$ if it had some good dyno numbers. And the tuning possibilities are so great. I really wish the micro had a built in data logger though.

JustinL · 09-10-2007, 09:24 PM

The first step is now complete. I got the wideband installed tonight. It's pretty straight forward; just follow the instructions that are provided and don't burn yourself. I thought that getting the old sensor out was going to be the death of me, but it turns out that it came out pretty easily.

I spliced power from Pin 18 of the DME. This is one of the wires that is switched with the DME relay. If you don't use a wire on an ignition relay, then the heater for the sensor will stay on when the car is not on. The wire is red with a yellow stripe... there are 2, either will do.

I spliced the ground for both the sensor and the lc-1 system (as recommended by the manual) from pin 17, Thick brown wire with a yellow stripe.

The yellow LC-1 wire is the narrowband emulator wire. This outputs a voltage between .1V and 1.1V. This guy gets spliced into pin 24. This is a green wire that comes out of a thicker green wire. To get at this bugger, you have to take the screw out of the plastic DME plug and slide it apart. There you see the green wire split from it's shielding wire and you can attach the new input. I'm only doing this so I can swap the DME back in without swapping o2 sensors.

All the other wires from the lc-1 are taped out of the way until the microsquirt is installed.

Then I turned on the system for calibration (as per manual) for it to do it's open air calibration. The sensor gets freakin hot, so don't try to put it into the exhaust until it's cooled down. While it was cooling I bundled up all the extra wire and found a spot to zip tie the controller.

After sensor and software installation I had a little panic attack when the laptop didn't recognize the lc-1. Turns out that I need to read the manual harder and install the terminator serial plug into the "in" plug. After that, the laptop recognized the wideband and everything on the test drive worked perfectly.

After that, shuffle the silver car back into the garage and go have some tea.

cauzomb · 09-10-2007, 10:52 PM

Has anyone tried to use the teeth on the cam belt sprocket for speed reference?

mfloren · 09-11-2007, 06:01 AM

did you install the LC-1 into the stock O2 bung??

because if you did you will constantly recieve a reading slightly richer then the car acually is.

the best place to mount the LC-1 is about 1.5 feet from the turbo after the down pipe.

this is done for two reasons.

1. heat, the temperature of the cross over pipe can exceed the temperature for the Bosch sensor used by the LC-1

2. pressure, the added pressure of the cross over pipe makes the sensor read ritcher then it acually is.

JustinL · 09-11-2007, 06:35 AM

Cauzomb- The cam gear has the same problem as the ring gear in that it has no missing teeth to detect angle. I guess if you were really adventurous, you could grind off one of your cam teeth

mfloren- Yes you are absolutely right about the sensor. In my silver 951S I have the sensor installed exactly as you described. 9 o'clock about a foot after the down pipe. However, this microsquirt is going into my red 944 n/a, which has about the perfect sensor bung installed from the factory right after the streams all merge into one.