Project Minerva: You restomod the Porsche you have, to be the one you want it to be

[evan9eleven]

Back to the metalwork: the reflector panel has to go, now it gets serious! This is a pretty straightforward job with a spot weld drilling kit. I’ll be welding up the holes and corners here later to more closely resemble the way pre-74 cars were in this area.










I decided to test fit the rear number plate panel kit, which also includes mounting for the rear bumper corners. You’ll recall I went with FG corners; I would definitely have preferred steel, but the kit with the adjustable brackets came with these in FG. Initial fit doesn’t look too bad. Famous last words.






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[evan9eleven]

The gap you see in the photo above is the space where the bumper corner to body gasket goes-- unfortunately a part too often omitted from backdates. One challenge is that the gasket has a slot in it, which mates up with a metal rail on an early car, to hold it in place. I opted to weld in some tabs along the back edge for this purpose, as well as fabricating a rail that runs along the rear quarter to keep the gasket tightly parked following the curvature of the fender:










Gotta say I'm really happy with how this looks!





While I was at it, I got a pair of OEM-style bumper support brackets. The bumper corner kit I bought didn't include these, instead relying on being fixed to the fender at the front of the corner, and to the adjustable bracket at the back. This would probably have been more than adequate, but I'm really not good at settling for adequate, so I figured these could only be a good idea.




In the process of getting the bumper corners aligned, I also ran into a challenge. The corners can be adjusted left or right as can the number plate panel; and the whole assembly can be adjusted fore and aft. However, the corners cannot be adjusted fore and aft independent of the number plate panel. Long story short, this means things don't line up as they should. So what to do... hack up the mounting bracket and add some rivnuts, so the part that the bumper corner itself mounts to can now be adjusted separately. Problem solved. All told getting the rear of the car sorted and looking right... a week of what used to be my spare time!




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[Jonny042]

Great work! Nice to see someone sweating the details, and doing it right.

[evan9eleven]

Originally Posted by Jonny042

Great work! Nice to see someone sweating the details, and doing it right.

There has definitely been sweating involved!

Thanks Jonny, that is a huge compliment coming from you.

[LukasM]

Sweet looking car already, Minerva blue is one of my favourite 911 colors as well and I also love the backdated look.

Are you going with green faces on the gauges? I would consider having John add a voltmeter to the tach, and ideally change the clock to a dual WBO2 while he is at it. Well you said you care about details and it's not my money...

Looking forward to following along this build, as I have a similar project ahead of me.

Cheers from Austria,
Lukas

[asandiego]

Hard rewarding work you’ve put in on this project. I just redid interior on my 78 targa. Had a very hard time finding the leather to even do this job, but over a years time completed it. Just wondering if you’ve considered an arrow blue interior, didn’t like it at first, but it has grown on me. Seems like it may be a good fit for your car color.

[evan9eleven]

Originally Posted by LukasM

Sweet looking car already, Minerva blue is one of my favourite 911 colors as well and I also love the backdated look.

Are you going with green faces on the gauges? I would consider having John add a voltmeter to the tach, and ideally change the clock to a dual WBO2 while he is at it. Well you said you care about details and it's not my money...

Looking forward to following along this build, as I have a similar project ahead of me.

Cheers from Austria,
Lukas

Hi and thanks for the nice words! Don’t worry, I’m doing a VERY good job of spending money on the details

I would classify this build as “Classic” in terms of things like gauges. They will have black faces and silver dots as in a pre-74 car, but in cooperation with John I’ve made a few modern tweaks. I can spill the beans with the image below. Even the clock is getting a new quartz movement and silver dot.

A dual AFR meter would have been nice, but John explained to me that the small meters used for this (re-purposed from old gauges, like fuel or others) don’t give much resolution. In other words, cool to look at but not near enough “swing” to really be useful for tuning. As I currently only have a single wideband meter, I’ll stick with this for now. I probably drove John nuts with all my details and questions, but he is fantastic to work with.

So the clock is staying, because I’m unusual and I like the clock. To make space for the AFR gauge on the left I went with a custom quad gauge that covers volts, oil pressure and temperature, and fuel level. That meant losing the mostly useless oil level gauge. Note that there is an oil can icon with light— though not yet operable, I’ve asked John to look at making a box that checks if the engine is fully warm and at idle, and that the car is stationary before checking the oil level and returning a light on/light off.

The tach is a nod to Spinal Tap, “goes to eleven” as I’m also a guitar player. The redline lamp is programmable to light wherever I want it to, meaning I can just set it to match the bada$$ engine I have planned after my wallet recovers from the restomod!




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[evan9eleven]

Originally Posted by asandiego

Hard rewarding work you’ve put in on this project. I just redid interior on my 78 targa. Had a very hard time finding the leather to even do this job, but over a years time completed it. Just wondering if you’ve considered an arrow blue interior, didn’t like it at first, but it has grown on me. Seems like it may be a good fit for your car color.

That looks great, nice work! Not sure what color the exterior of your car is, but looks like it could be champagne beige or something like that? I’ll bet the contrast with the arrow blue leather really works! Post a pic of the outside if you get a sec.

In my case I really didn’t want another blue-on-blue combo as the car was originally, but rather to have some contrast between the Minerva blue on the outside and something complimentary on the inside. So it will be in the two-tone combo I posted a page back, mostly in Bentley New Market Tan (a shade lighter than terracotta) combined with black accents.


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[evan9eleven]

I got the B-pillar rust hole welded up. This may not seem like a big deal, but it was a tricky area to patch for someone who doesn’t do this for a living, so it took some doing. I’ll work it over a bit more before spraying epoxy primer on the area. I also wire-brushed and sandblasted in the area in the rear fenderwell that backs up this repair. It will get primer, paint and undercoating. I got a bit obsessed with this job while I was doing it and didn’t take any in-progress pics, but to deal with the area properly I ended up cutting out a little more and making a patch panel that went in the door seal slot and 90 degrees out into the door jamb area.




Meanwhile the trimmer has started in on the interior. My original leather dash was thrashed, and I wanted to eliminate the center AC vent. I decided against a center dash speaker. While the interior details are of paramount importance, as you’ll recall I’m not duplicating an F-model. I find that those center speaker grilles often look wonky, so I’m going with a clean and simple look. Apparently he has reinforced the dash top with metal and fiberglass to get the desired shape and strength. Can’t wait to see this with leather!




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[TastyReuben]

Originally Posted by evan9eleven

Another thing to consider for anyone who lands here in the future curious about the dash backdate from Rennline: to install this, all the old dash padding must be removed. If you want to keep your cigarette lighter outlet, or the rear defrost switch for example, you will have to drill some holes for those in the Rennline part. However, the threaded part that holds these items in the dash is spaced for the old padding that you will remove. As a result, you can't really flush mount these items. I'm amazed that Rennline didn't think of this; I contacted them and they don't offer any solution. So I'll have my machine shop custom make this part without the spacer:

have you come up with a reasonable solution for this? Im looking for a low profile flat bolt to mount my headlight and defrost switch more flush to the dash kit, any guess' on the size or thread?

I'm also considering swapping out the switches for basic toggles if I cant figure out how to mount these properly, but the wiring on these is a serious puzzle.

[Jonny042]

You mean to tell me Rennline is selling a dash backdate kit and they don't even know the difference? I don't even have words for that...

The ironic thing is that my post that goes into this detail for the very purpose of illuminating this mystery is basically an advert for their part!

Anyway, like everything else Porsche did to "federalize" the cars, the switch mounting was a kludge more than a solution and is easy to fix, just order the mounting hardware and knobs for the early car (including the ignition surround).

Originally Posted by Jonny042

Not much backdate content lately, but here's some - the same light switch was used for years, but the mounting hardware was a little different to allow for the padded dash on later models.

Late style, with padded dash. Note spacer washer and plastic retainer, and impact absorbing rubber knob.



Early style, with chrome retaining collar.



Note the cool rennline billet headlight knob. Now normally billet and backdates don't really go hand in hand but the black anodizing looks really great, and they make an ignition switch surround and a glove box knob in the same finish, to match. I also picked up a "911" emblem for the glove box that matches the one on the decklid - no T, E, or S designation for this car.

[Jonny042]

The heater controls are another difficulty. I did it the hard (and very, very, expensive way):

Originally Posted by Jonny042

I managed to score a NOS, new, never used, heater control assembly from a fellow board member.... 73 and earlier used a cast aluminum (or pot metal?) assembly with quite a bit less writing on it!! It will also fit flush to the early dash trim the way it should.

Just like the turn signal and wiper switches, it is a direct plug and play with the rest of the wiring in the car, with the exception of a few of the small illumination bulbs which will no longer have a home.

The longhood version of the heater controls also has a few extra wires that terminate in spade connectors but it's not obvious what they are for. If you've spent enough time studying the current flow diagram for the SC and later you may have found the power supply to the fresh air blower indicator lamp to be a bit odd (as in, why is it run from the same fuse that powers the cigarette lighter?) - it all makes more sense if you look at the 1973 wiring diagram and see that these extra wires are for the Zusatzheizng. Well of course they are!

I had to use google to translate for me..... that's "auxiliary heater". I was able to remove these extra wires and also connected the + supply for the indicator light to the interior lighting circuit black wire, which conveniently runs right by. Which in turn allowed me to get rid of the blue wire that basically now does nothing.

Again, Rennline has you covered:

[Cairo94507]

Wow, love that new heater control unit.

[Jonny042]

Originally Posted by Cairo94507

Wow, love that new heater control unit.

It's actually just the billet faceplate and the chrome surround, for $325.00 Which is a lot cheaper than my solution, at least.

They also have a billet version of the later model surround which perfectly illustrates the different, deeper, bezel required to allow for the thickness of the dash padding:

[Jonny042]

Personally I'd go for the new controls included with the new/latest Classic Retrofit system... They'll let you get rid of the heat levers between the seats, too

[TastyReuben]

I opted to delete the slider box, and fresh air blower assembly. Heat is now dumped into the cabin just by control levers.



Dash is a work in progress, but is made from 2 rennline pieces instead of the backdate kit.

[evan9eleven]

Originally Posted by TastyReuben

have you come up with a reasonable solution for this? Im looking for a low profile flat bolt to mount my headlight and defrost switch more flush to the dash kit, any guess' on the size or thread?

I'm also considering swapping out the switches for basic toggles if I cant figure out how to mount these properly, but the wiring on these is a serious puzzle.

My local machine shop is making me a version of this fastener this week, but without the spacer portion. I've asked them to figure out the thread pitch and let me know-- if we know the thread then you should also be able to have something made as well. You could potentially find a bolt, but you'd still have to grind the head down and drill a hole down the center. Might be better to get some made. I'll report back.

[evan9eleven]

Just saw all the new posts. Jonny, great input here. I must admit that it didn't dawn on me to source the actual part from an early car, so I did it the hard way. Duh...

[evan9eleven]

Originally Posted by Jonny042

Personally I'd go for the new controls included with the new/latest Classic Retrofit system... They'll let you get rid of the heat levers between the seats, too

I went for the Rennline controls, as the new system from Classic Retrofit wasn't announced yet when I ordered. Also, it appears that it won't be available for a while yet. That reminds me, I need to check in with them-- I'd love to avoid installing this stuff twice!

[TastyReuben]

Originally Posted by evan9eleven

My local machine shop is making me a version of this fastener this week, but without the spacer portion. I've asked them to figure out the thread pitch and let me know-- if we know the thread then you should also be able to have something made as well. You could potentially find a bolt, but you'd still have to grind the head down and drill a hole down the center. Might be better to get some made. I'll report back.

thanks, that'd be awesome. looking at something like this but unsure of fit:

https://www.summitracing.com/parts/edm-tsb-mb?rrec=true

EDIT:
according to this thread the bolt required is M10 x 1, extra fine
https://forums.pelicanparts.com/porsche-911-technical-forum/1062761-thread-size-headlight-switch.html