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!

Virtual Delorean Weekend 2020 - a tour of my D

I participated in the Virtual Delorean Weekend 2020 by giving a video tour of my D:

Unfortunately, the audio is terrible... also, I did the whole thing in one take and since I don't know the first thing about video editing you will have to put up with the "seven... uuhh... seven... uuuh..." stuff.

New starter

My efforts to find the lazy starter issue continues. My local O'Riley's tested my starter and concluded that it was bad. Not that they gave me any results or anything; they just took it out back and came back and said "it's bad" so I ordered a new one. It's a Nissan starter. Why you ask? Well, SEO Motorsports' original Delorean conversion project used a Nissan 2JZ engine so the adapter plate between the engine and bell housing was really developed for it. Consequently, the VR6 adaptation is a revised version of it - presumably just a change of bolt pattern on the engine side; there really was no reason to change the design to accommodate a different starter, which is why I have a Nissan starter; model# 17904N, 23300-AM600 to be exact.

Adapter plate with starter recess

Old Hitachi starter with model number

For good measure I also replaced my Optima battery. O'Riley actually deemed it good but I've had it since 2011 so it was probably just a matter of time.

The result? Well it definitely cranks better but it's still not as peppy as I would like. The other day my buddy Marc suggested I run a jumper cable directly from the battery's (-) post to the engine block to see if I may have a grounding issue and it really made a difference. Next up: Improve the ground!

Oil return line

The oil return that runs from the turbo outlet back down to the oil pan had developed a small leak resulting in an occasional drop of oil hitting the exhaust with lots of smoke and smell as a result. The notion of an engine fire is scary stuff so it had to be addressed quickly.

The old hose, taken apart

As I examined the hose I concluded that the O-ring in the upper AN fitting may have taken a beating given how close it sits to the exhaust. I took the hose over to my buddies Brandon and Ryan at BSP Motorsports who agreed. They fabricated a new hose with O-rings rated for the extreme temps. We also added a high temp sleeve to ensure this is addressed once and for all. Here is the result after I installed it:

New oil return hose, upper end

New oil return hose, lower end