All AutoCross MegaSquirt Performance

DD-EFI Pro Dash Install

I recently purchased DD-EFI’s new 10.3” Pro Dash for my 00 Miata.  Kurtis, the owner of DD-EFI had made a post that they were phasing out the 7” dash they have offered for some time now in favor of the 10.3”.  This prompted me to message Kurtis about getting on the list to be one of the first to get one of these dashes.

In the months leading up to the DD-EFI’s launch of the 10.3” dash I had been researching ways to make my own DIY dash.  What I found is a seemingly easy task got really complicated really quickly.  I had found ways to add a CAN bus, GPS, and even power the dash, but I would still need to learn how to program the hardware to the OS and TunerStudio.  This still didn’t provide me with a screen, with drivers, and functioning with my theoretical dash, nor did it provide things like indicators, or fuel, or any other sensor that wasn’t built into my MS3ProPnP. 

In the end the cost and time and experimentation kept getting larger.  I conceded to the idea that I’d rather spend my time improving the other bits of the car than sorting out all the details.  I decided the best bet was to purchase the 7” dash from DD-EFI and let go of the possibility of a larger screen.

It was very fortuitus that the same day I had been looking at ordering the 7” dash Kurtis’ post appeared in my Facebook thread.  He replied in minutes letting me know that they were still working on fitment and the dash would be available soon.  I couldn’t give him my money fast enough.

Fast forward to today, and I am loving my dash.  I can’t say enough about how well sorted it is.  I have all of the information missing from my various physical gauges in a easy to see display that I can change on a whim, use instead of a bulky laptop to tweak (or retune) the car, and have any information that my car’s ecu has.  When I have ran into issues – all of which have been ID-10T errors on my part- DD-EFI has been able to help me sort my issues.  Kurtis even remoted into my dash at one point.  Amazing!

Bellow is the installation of the dash and the things I did to make everything work as advertised.  The biggest tip I have is trust the instructions.  There were several points I questioned if the instructions were correct, I contacted DD-EFI and found they did mean what they wrote.

The first thing I did, after I admired my new dash, was grab the wiring harnesses that came with the dash, and the wiring instructions from the support page:

The folks at DD-EFI made things very easy.  The instructions have each wire color-coded to the harness they send.  So it is quick to identify which harness you have and what it should connect to.  Looking at the back of the harness with the tab down.  The wire colors should match the diagram in the instructions

I took the time to print labels for my harnesses with some heat shrink.

There is plenty of wire on each harness and about 6 feet of wire for the CAN interface. 

Now that I had everything labled I needed to remove the OE gauge cluster.

There are 3 screws under the steering column that need to be removed so the gauge cluster cover can come forward (toward the steering wheel)

The bottom of the column should come down now.  It will need a little gentile prying but it will come apart.

Once it is separated the top part should lift straight up.  You can then start to remove the cluster cover.  I started by using a nonmarring tool to pry the lower part of the cover forward on both sides.  Then I pulled the top part straight forward – directly to the steering wheel and NOT up.

These clips and the peg hold the cover in place.

There are 4 screws in the corners of the dash that I removed.  Then cluster then would pull forward.  On the back there are 3 connectors that need to be removed by pushing the tabs in and gently wiggling them out.  This is much easier to see if you look from outside the car through the windshield.

With the cluster out it I needed to figure out which wires in the OEM cluster need to be wired up to the new cluster.  DD-EFI provides a great diagram for this: OEM Gauge Cluster Refrence Sheet

I did go abit off script in the way I got some of my power inputs.  It wasn’t explicitly listed where or how to get these, but with a bit of digging on the web and a multi meter you can find what is needed.  I will highlight the things I did that were not explicitly in the instructions with RED text. 

Here is a list of the things that are needed to wire up the harnesses to the new dash and where they go to on the existing harness.  “Switched” will be power that comes on with the ignigition swithch in the on / run position.  For Ground I used a ground block that runs directly to my negative battery terminal.

Main Connector:

I/O Connector:

Digital Connector:

Altenator Excite Connection:

I added a T-Tap to each of the wires above and a male spade terminal to the corrisponding wires on the new dash harness and plugged them in.  I did not remove any of the harness wire DD-EFI provided.  There is plenty of room behind the dash for the extra wire and it leaves room for error.  I did use a velcro wrap to keep each harness togeather.

I also needed to get the CAN connections to the ECU.  My ECU is mounted in the stock location with a Singular Motorsports bracket, so I don’t need much wire to reach it.  If you have your ECU in the glovebox or in the trunk for that matter DD-EFI has left plenty of wire to make this happen. 

The optional rear connector needs to come out of the MS3 to add the CAN connections.  This isn’t the easiest task, but it can be done.

I used a panduit strap as a makeshift fish tape to pull the wire down through the dash.

I marked the connector red and black whre the CAN H and CAN L.  This makes life easier when trying to remember which hole each wire goes in especially when most of them are not filled.

Megasquirt provides pigtails that have the correct connectors on them with the connector, but that would mean I would need to solder or crimp the wire from the DD-EFI dash.  You can debate on which is the best and why, but neither seemed acceptable for a data connection.  I ordered the connectors I needed from Ballenger (Part # CONN-100748).  Hopefully this will provide me with the best possible connecton to the ECU.

With the CAN connections wired I plugged the connector back in to the ECU and ran my USB serial cable to my dash.  I have my serial connection in my glovebox for easy access and this meant I needed to fish it back over to the gague cluster.

The GPS antenna also needs to be run.  This should not go under the dash or anything other than the windshield.  I made a small indention for the wire under my dash cover by heating up a round shank screw driver with a torch.  I then ran it under the cover to create the indent, but not impact the top of the cover.

CUSTOM 12V For Dome Light

There is also an optional 12v connection to the dome light / door switch.  The door switches in the Miata are switched negatives so that will not provide the 12v needed.  To remedy this I added a relay.  The switched leg of the dome light is wired to the dash as a White Wire with a Red Stipe.  When either door is open this wire is grounded.  So I added a negative switched relay

86 and 30 pull power from the unswitched 12v source (Blue w/ Red stripe)

85 is connected to the Door switch (White w/ Red stripe)

87 goes to the blue 12v input on the new dash harness

Now that everything is wired upi tucked the wires back into the open space under the dash. And pushed the dash back into its home.  Using the 4 provided screws.  Putting the cover back is as easy as pushing it back into place.  Then its just adding back the steering wheel column covers and screws.

After things are back togeather all that is left is to turn on the ignition and admire how wonderful it looks.

VSS (Vehicle Speed Sensor)

The GPS gauge does a fine job of tracking the vehicle speed.  It has drawbacks – it can lag at times, it can be sensitive to weather conditions, etc.  I wanted more of an OEM feel when it came to my speedo and the DD-EFI dahs has a plan – the OEM VSS.

With out getting too deep into a subject I’ve only recently learned about, and not fully versed in, I want to lay out what is needed to use the OEM sensor.  The VSS on the 00 Miata is a VR sensor which puts out what is basically an AC current across 2 wires.  The OEM dash had a circuit that converted this to speed on the speedometer. 

To use this information directly in the MS3 this signal needs to be converted to a digital signal (5V DC).  This can be accomplished via a VR conditioner like AMP AXM-120. It also requires the apporpriate Deutsch DT Grey 6 Pin Connector, and everything to be wired up.

Alternatively, and perferably, connecting the speed sensor to the dash directly is free and super easy to do.  The VSS simply wires in to the VR1 +/- or VR2 +/-.  From there there are a few things to test the singnal and set in the dash.  Here is how I connected my dash.

First we need to identify the wires in the OEM harness and where they need to go on the DD-EFI dash.

Just like before I used T-Taps to connect to the OEM harness and the appropriate wires on my new dash.  This time I wanted to test the sensor because I was not 100% sure I had the correct wires. 

To do this I put the rear of the car on jack stands and used my multimeter on AC and connected it to the Orange and Yellow wires to verify I saw AC current and that it increased as the speed of the car increased.  The voltage was low .2 or so V at idle in gear.  It increased a tenth of a V as I slowly increaced speed. If you don’t see this voltage you either have the wrong wires or you have a bad VSS. Now that the VSS wiring was confirmed I could connect it to my DD-EFI harness.

Next I went into TunerStudio and changed Device at the top left from Miata to DDEFI.

Then I clicked Extended Control tab at the top center and clicked Speed and Shaft RPM settings.

On this screen I cahnged the Speed input to PWM1.  Below that you should see Number of teeth – this is the number of teeth on your speed sensor.  Mine has 21; you can pop a Goog and find what yours is.  Then the wheel diameter.  Mine is 23.07”.  To start I’d leave the final ratio at 1.  It is likely worng but this is the easiest thing to change to adjust the speedo to be correct.

This should be what you need to see speed on the speedo.  In the dashboard right click the Speedometer and click ProDash (DDEFI) then click Speed – speedGauge to set your speedometer to the dash PWM imput we set previously.

Now, with the car still on the stands, crank the car and put it in gear.  Don’t worry about the reading as long as it changes with the acelerator.  If it does not you may need to swap VR+ and VR- which can be done live (No need to shut down).  If you still don’t get speed try going back to the previous step and setting the speed input to PWM2.

After you have verified you have speed you can now road test at low speed.  My speedo was pretty far off (compaired to Waze)  It would show 5 mph at almost 12.  To correct this I lowered the Final drive to .5 – the lower the number here the more speed the speedo will show.  At .5 I was still off my a few MPH so I tried .3 which showed me doing 13 when I was doing 11 so I had gone too far.  .4 was really close but just a bit off.  I landed on .42 for my car with a 5 speed and 3.9 rear end.  Once I had that dialed I went for a highway run and all looked perfect compaired to Waze.

I think it is worth closing TS after any changes to your dash.  This way you are prompted to save changes to the dash.  You can also right-click and click Load / Save.

Leave a Reply

Your email address will not be published. Required fields are marked *