Belt tensioner

The belt tensioner had started an occasional squeal and chirp. I found a perfect drop-in replacement on Amazon for about 90% less than the equivalent VW part. Perfect fit, perfect quality. The VW model number was even cast into the housing - the audacity... Oh how the Chinese have mastered the art of reverse engineering on a dime...

Old tensioner on top, replacement at the bottom

Digital dash (finally)

It's been nine years since I started talking about it but it's finally happening. I have purchased the digital dash extension of the MS3 Pro, referred to as DD-EFI. I opted to the 12.3" Pro Dash model. It comes with with all the analog and digital inputs you need to display all parameters you would expect. The display is touchscreen but I purchased the wireless keyboard regardless.
Here is the stock instrument panel before I started taking things apart:

(Note the disjointed plastic surround at the top that I have never been able to get to seat properly since I had the binnacle recovered. Good thing that will be gone.) 

I made a mock-up of the display including the computer to doublecheck that the stock binnacle can be used:

Looking at it from the front. I have a custom, extra-wide bezel on order to fill the entire width of the binnacle. Set me back $50. A steal:

Work is underway:

   

There are basically five separate connectors on the DD-EFI dash: Power, CAN-Bus, USB cable (b/w ECU and dash), Digital In, and the Analog In. There is also a GPS for speedometer and odometer but at this point I think I can trigger the speed input signal from the Crank Shaft Position sensor so the somewhat less accurate GPS is my backup for now. 

For the power you need:

12V always on
12V switched
12V optional switched (for triggering dome lights, door switch etc)
12V dimmed
Ground

I was pleased to find that the plug for the digital clock in the console holds all the above power parameters (check on 12V dimmed) so I made a harness for the clock's power plug. The clock didn't work regardless so I will be more than happy to retire it (for the moment).

(pic of power plug)

Binnacle re-recovered including custom sized Bezel

Here is what the re-recovered binnacle from Shawn Cook Auto & Trim in Murphy, TX looks like. He did a good job smoothing out the sides of the binnacle and also creating a distinct step for the bezel to mount against from the back. He matched the vinyl and stitching from before to make sure it it matches the rest of the interior. 

For the CAN-bus I traced the two wires from the ECU and soldered in an extension between it and the dash. The 6 ft USB cable turned out to be short so a longer, 10 ft d:o, was procured.

Digital In: The following discrete inputs were chosen: (may change)

DI1: Left turn signal            DI5: Oil light

DI2: Right turn signal          DI6: Low fuel  

DI3: High beam                   DI7: Door ajar

DI4: Low beam

Analog In: This is where the confusion started. The so called Pro Dash Complete Manual is indeed detailed and is (almost) accurate (several screenshots with software selections that did not exist in my Tunerstudio) but to my astonishment it only covers the input/output aspects and the settings for such. It completely leaves out how to create a dashboard and how to build your gauges and how to make your input selections. It may sound intuitive but there is myriad of selections that if not completely correct, the gauge wouldn't read right. Also, you need to be clear on which inputs come from the ECU and which ones come from the external sensors, and there is no common sense delineation between the two. I did come across a list of the ECU parameters and once I learned that, then I realized why a given input that resides in the ECU could not be read from the vehicle sensors, and vice versa. An example: I tried to make Battery Voltage as one of the analog inputs to the Digital Dash but the analog in selections only consisted of pressure, temperature and travel - so what about voltage? Once I learned that voltage comes from the ECU then I had a working battery voltage gauge in minutes, and so on. So for posterity, here are the ECU parameters (need to find where I found them):

RPM                                           Boost                                        Voltage

Coolant temp                              Target Air/Fuel Ratio (AFR)    Spark timing

Manifold Air Pressure (MAP)    Actual AFR                              Miles per gallon  

Manifold Air Temp (MAT)        Closed Loop Idle                      Shift light

And here are the Analog In inputs that were chosen:

AI1: tbd                  AI5: Oil temp

AI2: tbd                  AI6: Oil pressure (pre-config)  

ADI3: tbd               AI7: Fuel level (pre-config)

ADI4: tbd

A pic of your truly, working away during the coldest couple of nights of the year, trying to get it ready for the upcoming North Texas Irish Festival: 

Feb 18, 2025. Quite possibly the coldest evening I had ever experienced in Texas. But, hey, gotta carry on... 

The void inside the bezel/behind the digital dash computer was used to house the terminal strips. In this picture you can see three terminal strips:

The two top ones mimic the vehicle's stock instrumentation the way the connected to the stock instrument panel with connection points A1-A16 (ref. Delorean wiring diagram) at the top and B7-B12 below that. The bottom one connects the outputs from the Breakout Board (further down) to the digital dash. I also put heat shrink wire labels for easy identification.

Terminal strips

Terminal strips as seen thru the windshield

work in progress

Another thing I learned was that my stock Delorean oil pressure sensor would not work. It is of the one-wire type so I think it is simply a circuit with a variable resistor. Not that it was explained explicitly in the manual but before long I realized why DIYAutotune sell sensors too, as the Digital Dash is designed for a 0 - 4.5V input signal and those are the types of sensors DIY Autotune offer. I opted for the combo oil pressure/oil temperature sensor by Low Doller Motorsports. It had an 1/8" NPT, just like the stock sensor, and was easily replaced. The cable was routed into the cabin via the (electrical cover) and was just long enough to reach the little cubby under the shelf where the ECU goes. Here I mounted the Breakout Board where I terminated the oil pressure/temperature sensor wires. I also pulled the Fuel level input wire to the breakout board, and from there I connected the three signals to the digital dash up front. That part worked out really well.

open breakout board to the left; cover installed to the right (below ECU)

Once I understood the delineation between data from the ECU and vehicle sensors, another quirk in the manual was it showed that you needed to make that selection (MS-ECU vs DD-EFI) up front. I searched high and low for that selection only to find that, in my software version, it has been changed to a local setting within the parameters you are working on. It may sound simple now but caused unnecessary confusion nevertheless.

Another minor curveball was that the screws that attached the display to the bezel had become too short. Reason being that the upholsterer had wrapped the vinyl around the back of the bezel (as I had expected him to) which resulted in the display being separated by 3-4 mm from the bezel. The solution was M2.5 x 12 mm screws specifically for plastic, from McMaster-Carr. Perfect.

Original (black) screws being replaced with longer (stainless) screws

The dash could now be test fitted in the binnacle:

The entire binnacle assembly installed very nicely in place. There was plenty of space to tuck in the terminal strips and excess wiring.

To facilitate binnacle removal in the future I decided to only use the two rear-most M5 studs to secure the binnacle and to my amazement it held perfectly in place. Instead of the two regular nuts I ordered some 20 mm long nuts - reaching up above the steering column and around the A/C duct is a pain, so the tall nuts will surely help. Another thing I added was a pair of USB extension cables for two of the dash computer's USB ports; basically a 18" cord with male/female ends that extend down under the dash which provides easy access to the little dongle for the wireless mouse as well as inserting a thumb drive.   

Another pic of the almost completed job... only seat and steering wheel left:

   

Improved throttle bracket

 A source of irritation has been that the throttle tends to be s little sticky when you were giving it just a little gas, just off-throttle, so I  decided to do something about it. The issue was that the angle at which the throttle cable lines up with the throttle body was really awkward and caused the stickiness. My solution was a piece of stout 1 x 1/4" aluminum bar stock and a simple pulley that lines everything up.

Throttle cable with pulley (no worries - the cable was not cinched up yet)

Eventually I would like to build a drive-be-wire system to get rid of the old school throttle cable. Looks like the DBWX2 might be a viable option.

Slow starter issue - FIXED!

It’s been a long time coming but I have finally resolved my slow starter issue. Back in 2018 I upsized the positive cable; I also replaced the starter but none of those were really the problem. The real problem was a poor ground.

To address the poor ground I purchased:

• 25 ft of 1/0 AWG Pure Copper Power Ground Wire Cable
• a handful of 1/0 AWG 3/8" Stud Copper Wire Lugs
• a set of crimping tools
• and some dielectric grease

Then I ran one cable from the battery to the transmission:

Grounding point at transmission

... and another cable from the same point on the transmission to the original grounding point i.e. to the reinforcement plate of the right rear trailing arm:

Grounding point at trailing arm

I also ran an additional cable from the same point on the transmission (left cable in the pic below)...:

Added ground cable running to the front (left cable)

... to the common grounding point for all accessories in the front, including the headlights:

Front grounding point

A word of caution, getting the trailing arm bolt back in took a ton of McGuyverism as the alignment of the plate and bushing etc. had shifted ever so slightly and it was a bear to avoid cross-threading the bolt as I was trying to getting it back in. The solution was to get a 5 mm longer bolt than the original (same spec) and grind the first 5 mm to a point so it would align itself. (An even longer bolt with a more pointed tip would have helped but that would have caused it not to screw all the way in as it would interfere with the frame on the backside.) So, the pointed bolt and all kinds of clamps and jacks to help lining things up got the job done. Oh yeah, add the minimal ground clearance with everything just a couple of inches from your face just added to the challenge. In hindsight, I do not see this point as a good grounding point anyway. A better option would have been to modify the ring terminal into a spade terminal and that way only having to loosen the bolt a bit – not pull it out completely.

 So – with all that in place the car cranks like crazy:

And the voltage gauge is showing a healthy 13+ V!

Looking forward to enjoying the (hopefully) brighter head lights at my next evening drive!

New variable displacement A/C compressor

My D uses a variable displacement air-conditioning compressor - a Sanden SD7V16 model #1216 to be exact (yes, Dan!) - which is as the name would indicate a compressor that varies its displacement automatically based on the prevailing conditions, without clutch cycling. Given that I am running a turbo setup, i.e. low torque at idle, the clutch cycling of a fixed displacement compressor would stall the engine at idle so a variable displacement is a MUST.
The heart of the variable displacement feature is the so called Mass Flow Compensation Valve (MFCV), but if it starts to act up the compressor will stop modulating which is what appears to have happened with my compressor - it was stuck in minimum displacement so it was time for a new one. 

Old and new compressor

Old compressor removed

New compressor

I got about 75 cc of clean (no sign of any trash in the system) but darkish looking oil out of the old compressor and after having drained the replacement compressor I added about 100 cc of PAG 46 (equivalent to Sanden SP-10 oil) to it before installing it. The system pulled a good vacuum and after re-charge it was spitting ice cubes again!

Square Wheels!

Another weird aspect of Deloreans are the staggered wheels, i.e. 14" in the front and 15" in the rear. The initiated would tell you that the purpose for that is to supposedly provide more grip in the rear for an already rear-heavy car. While that may be true, finding a matched set for all four corners has become virtually impossible for good reason: 14" tires are all but extinct and look hopelessly dated and 15" aren't far behind. To alleviate this problem, I decided to purchase a set of rear rims and put them in the front. Going from the stock 6" wide front wheels to 8" is perfectly doable - with some modifications.

First of all, I selected a set of Toyo Proxes R1R SL 205/50R-15" ("Extreme Performance Summer" per Tire Rack) tires with a "V" speed rating. Of great significance here is that this tire dimension provides a virtual identical circumference with the stock 195/60-14" tire i.e. the speedometer is not affected. 

Stock front wheel on the left; new front wheel on the right

Same OD!

Secondly, I purchased a new set of Upper Control Arms  from DMC Houston and had them drop shipped to Reid Performance who modified the UCAs with a -3 deg camber angle. This should not only help turn-in but also provide some added fender clearance at the top of the wheel - and of course - it looks cool. In this picture you can see how four new holes for the Upper Ball Joint have been drilled further in to provide the added camber:

Modified UCA

Something I had not expected is that the new UCAs threw the toe-in out of spec but that was easily adjusted. 

Thirdly, the fender lips had to be rolled:

Fender rolling in progress

The front spoiler where it meets the front of the wheel arch also needed to be modified (basically, the plastic was shaved using a Dremel tool) for more clearance.

In the end my new 8" wheel fit like a glove - tight, yes - but no interference from tilt to tilt. And it looks pretty damn good too (at some point I need to re-spray all wheel for a uniform look):

To me it's striking how dated the rear wheels look... so now I'm thinking an identical but customer made rear rim with the diameter increased from 15 to 16" and another 25 mm negative offset ("poke"). I might out put out some feelers with some custom wheel machinists... 

Upper Control Arm bearings

The movement of the Upper Control Arms relative to the frame is to a large extent a function of the amount of torque you put on the Wishbone Pivot Bolt (#43) and Nut (#29). It's a shame considering the fine engineering modifications many of us have done to our suspension, only to have the movement hog-tied by the thru-bolts' arbitrary clamping force. Also, there seems to some confusion within the Delorean community as to what washers, and how many, go where.  

I started researching how to decouple the bolt torque from the UCA movement and found what appeared to be a very good solution from my favorite supplier McMaster-Carr:

• Thrust Bearing p/n 5909K31
• Thrust Bearing Washer p/n 5909K44

Up to this point, this is how my UCAs were arranged:

Bolt head - Large Washer - CONTROL ARM - Two snub washers - FRAME - Two snub washers - CONTROL ARM - Large Washer - Nut

So, replacing the two snub washers with one thrust bearing and two thrust bearing washers on both sides would result in the following: 

Bolt head - Large Washer - CONTROL ARM - One thrust bearing washer - One thrust bearing - One thrust bearing washer - FRAME - One thrust bearing washer - One thrust bearing - One thrust bearing washer - CONTROL ARM - Large Washer - Nut

One thrust bearing and two thrust washers

The thickness of a thrust bearing and two washers is about 0.2 millimeters more than the combined thickness of the two snub washers so the fit is pretty tight and can be a little tricky to get in there, but once it's in there it is as if it was "engineered in".

Some pictures with the thrust bearings/thrust bearing washers in place:

Thrust bearing washer/thrust bearing/thrust bearing washer. Right front wheel; left of UCA. 

Thrust bearing washer/thrust bearing/thrust bearing washer. Right front wheel; right of UCA.

Is it worth it? Hard to quantify but from my personal point of view this modification is definitely working: If you grab the bolt head with one wrench and the nut with another wrench, the Wishbone Pivot Bolt/Nut spin freely about its axis even after they have been fully torqued down. I'd say that it's a testament to its effectiveness!