When Well Enough Can't Be Left Alone; Backdate, EFI/ITB, AC, and more!

[Showdown]

Hasn’t been driven in over a week, I somehow convinced myself that now would be the right time to start installing a hand throttle and of course there are a million little checklist things to do.

Sounds about right.

[chrisbalich]

Originally Posted by Showdown

Hasn’t been driven in over a week, I somehow convinced myself that now would be the right time to start installing a hand throttle and of course there are a million little checklist things to do.

Sounds about right.

My dad likes to say, "Ain't nothing but something to do."
I have full confidence you'll get your list sorted in advance of next Saturday.

[Showdown]

For some reason, it always seems like a good idea to add another ball to juggle, or plate to spin when one is already pushed to the limit...

Currently my work is bonkers crazy, I'm off Friday to film for my YouTube channel which has become an all consuming second job (that I love, but it's still exhausting), Saturday is Checked It Out which I'm really excited for as it kind of catalyzed this whole project a year ago, then Sunday I leave for a week in Belgium to once again film for yet another project that I'm putting together. I return on the 1st and take my kids camping for Labor day weekend on the 2nd.

What's the point of me relaying that pandemonium... well, this week I though it was the perfect time to retrofit my car with a hand throttle... because the thought of not being swamped to the point of head spinning seems too easy right now...ha!

Also, keeping busy AF is just about the only way I can move through each day, hour, err, minute...

But I digress.

So, why a hand throttle you ask? After all I did just spend a lot of time installing a new-fangled EFI system complete with a MegaSquirt that's overly capable of handling an IACV. Well, back when I started the project and built the harness I didn't think I'd need an IACV, heck I didn't even know what one was (remember, deep end meet Julian, Julian...godspeed!)

Turns out having one makes starting these cars pretty nice. I have my idle at 1000 rpms and I like it there. I'd like to go a bit lower but after a LOT of adjusting, I have a steady idle, 45 kpa vacuum signal and the car likes it there. Any higher or lower and much like Bartleby, the car seems to not prefer it. So 1000 it is. The thing is, to keep that idle once the car is warmed up, it's going to be lower when the car is cold. Low enough that with the engine at 72 F it's really choppy and can die.

So, abck to by a hand throttle and not a fancy IACV... Well, I didn't want to tear into the harness, I didn't want to add any more stuff to the engine bay, I most certainly didn't want to introduce anything that was going to mess with the strong vacuum signal I tried so hard to get, I've seen others have trouble with IACV's and also, hand throttles are really cool, purely mechanical and did I mention, cool.

So, how hard could it be?

Go buy a hand throttle. Nope. NLA.

Go buy an old parking brake with hand throttle assembly on Pelican. Nope. No answers.

Go buy an old parking brake with hand throttle assembly on eBay. Nope. No way I'm spending $1000

Ok, so I'll build one myself from the PET. Bwahahah!

Turns out, most of the parts are available. It also turns out that the parts that are NLA are the really important ones!

The knob, the lever, the little rubber thing that pushes on the throttle cable, and a few other parts are available.

What's not available is the stop nut that clamps on the throttle cable, the double threaded stud to fit an assembly with two heating levers, and some strange but critical washers. Ugh.

Ok, lts problem solve.

Stop nut: SketchUp and we're good. I designed a replacement wit a modification of two stop bolts instead of one for extra strength. I had 3 versions 3D printed: carbon reinforced plastic, Aluminum, and Steel.

The steel was out of spec and not all that great. The aluminum was really nice but again, a bit out of spec, the plastic was spot on perfect. the tolerances for aluminum and steel printing are still pretty high but plastic is really tight. That said, the aluminum could be worked with a file, so I settled on that.







The next two parts I had to fabricate and didn't take any photos of because I was working hard, pissed that I had to make these parts and just wanted to get it done. The washer was cut from sheet steel and bent to match the existing one on the heater knob side- it's used to isolate the lock nut from the rotation of the lever which would loosen it up and as a stop for the lever so that you can't go to 5000 rpm.

The stud I ordered was about 1cm too short so I cut it down and welded on another threaded nut. It wasn't pretty but nobody will ever see it so I'm ok with that.

Assembly, like everything Porsche was a pain and took more time than I wanted but i made it harder for myself because I left the seats in and didn't disassemble the hand brake assembly.



In the end, I managed to get it all put back together and now I have a working hand throttle. Just in time for me to start another project before Checked It Out... ;P

[chrisbalich]

I really love how we midwesterners absolutely can't be ready ahead of time for any car event. There's always another thing we think we can cram in when a 'sensible' person would just call it good enough.
I made more tweaks to my calibration 20 minutes ago.
You've [literally] built a hand-throttle for your car this week.
MD was working on lights last night.

[shoooo32]

The throttle bell cranks are different for CIS cars vs longhoods - this makes the hand throttle super touchy when adapted to later cars. Unless you've already swapped the bell cranks when moving to ITBs, in which case, I'll see myself out...

[Tom_in_NH]

Shoooo32, are you referring to the bell crank on the transaxle? If so, I'm confused. I'm about to add manual throttle control to my '83 SC. I was fortunate to locate an early e brake with throttle control, albeit in desperate need of restoration. I do remember reading that there is a difference in bell cranks on the transaxle as you have related. However, I just did a search for an early bell crank ('72 for example), to fit to my now carbureted '83 SC. The search results on our hosts site list a part that is described as fitting '72 to '88. So, not really indicating a difference from long hood to short hood era.

[shoooo32]

I'd rather not derail Julian's thread, but this info is a massive time saver. Jack Schroder did the heavy lifting and I've corroborated portions of it on a 2.7 BAE turbo I built for a friend.

Hand throttle part #s

Lever 901 424 037 00

Knob 901 424 323 01

Value lever 901.424.317.00

Accelerator lock nut 901.424.319.00

Washer (x2) 911 424 737 00

Extended main stud to add the hand throttle 901 424 519 00

Lever lock plate 911 424 735 04

Cir-clip (you need 1 m6 washer) N01-243-51-OEM

Washer 911-424-735-02-OEM

You will also need 1 additional M8 lock nut for the new stud that goes through the hand lever, ebrake, and 2 heater controls. New nut goes on the hand throttle side.

Accelerator backdate parts

Bell crank (early style) 901-423-027-03

Bell crank to carbs linkage
901-423-026-02 (early 911 weber) 901-423-026-03 (later 911 zenith)

Accelerator coupler to bell crank extension rod 901-423-223-01-OEM

Gas pedal 901-423-010-01

Pedal stop bracket 901-551-065-20-OEM

Pedal stop nylon SIC-551-671-20

short ‘77 throttle linkage 911 423 043 00

[chrisbalich]

Tom,
I'm 90% certain the bellcrank Tony is referring to is on the engine, not the trans.

[Showdown]

No, I did no adjustments to the bell crank. If it doesn’t work well; angle grinder and full send.

[chrisbalich]

Originally Posted by Showdown

No, I did no adjustments to the bell crank. If it doesn’t work; angle grinder and full send.

I love it.

[Showdown]

Well, it's been a minute so I figured while it's pissing rain all day today I'd get an update in.

Checked It Out was pretty awesome. It was great to finally meet a whole bunch of folks that heretofore I've only known by their screen names and cars. Suffice it to say, nobody disappointed and lots of laughs were had. I took precisely one photo- I was to busy chatting and enjoying myself!!

The day after Check22 I hopped on a plane to Belgium for the week to do some work. It was a bonkers busy trip with 14 hour days. Unfortunately as we were hauling a lot of film gear, we needed an SUV which made driving less fun than, well anything else. It was a BMW X3 and I did get to toss it around some of the tiny and hilly roads around Liege; my passengers were white knuckling the whole time! I was desperately missing both my Colnago and my Porsche...

I returned to the states and immediately had to take my dog to the vet to be euthanized due to cancer. Devastating to say the least.





Just a few hours after saying goodbye to Miko I packed the kids up in the car and headed to Wisconsin for a Labor Day camping trip which was awesome.

Coming back to reality was rough for sure!

I've been sneaking out of work when I can for an hour here and there to do some tuning using Jamie's Left Foot technique in anticipation of my proper dyno appointment on the 21st. I've gotten the car tuned to maybe 85% and it runs really well. The AFRs are getting really close to the map and lots of the stumbling I was experiencing is now gone.

I'm super excited to see what the tuner can do. Unfortunately he won't let me watch or even be present for anything other than the power pulls which is disappointing but I totally understand.

And because everyone likes pictures...

[rwest]

My condolences Julian,

Miko looks like he was a fantastic dog and you treated him like a king.

Car looks great and what a coincidence, I also have a Colnago! Great bikes for sure.

Rutager

[chrisbalich]

Julian,
Sorry to hear about Miko.
Glad to hear about the rest of your update. Sounds like you made the most of Belgium & Labor Day.

[Hulley]

My condolences Julian,

Both my pups are old and I expected to be broken hearted any day now, glad you're back safe.

[Showdown]

This was supposed to be a Monday morning update but I just got too darn busy!



Last week while having a few adult beverages and perusing the great and wild interwebs as one does, I employed the use of my heretofore relatively unscathed credit card and well, scathed it a bit.



I purchased a pair of BF Torino Nurburgring R seats. These are the reclining version of the ever popular throwback 60s and 70s racing seat found, well, everywhere.



My comfort seats are tired and look a bit out of place in the car. Refreshing them would cost more than it's worth so new seats seemed to make a lot of sense. Also, the new seats will be a LOT lighter.



The only problem is that they only come in variants of black and that just won't cut it for my cork colored car. I love the brown/white combo so I'll have to do something about the seats.



Did someone say WINTER PROJECT?!



I have decided that I'm going to take brand new seats and rip off the perfectly good upholstery to recover them to match the car.



Fabric and leather samples arrived and the leather was an easy match. Choosing the fabric for the inserts on the other hand is proving more difficult. Oh, some of the leather will be perforated with the same pattern as the headliner and dash insert that I made.



I present to you the following:



The whole lot







Option 1







Option 2







Option 3







Option 4







Option 5









My favorite is Option 5; a wool boucle that looks to some of the great Mid Century Modern furniture pieces by Knoll, the Saarinen Womb Chair in particular. It's also the most expensive by far. BY FAR.



Options 1 & 2 are also nice and in the running. Please feel free to tell me your favorite and include a cultural, aesthetic and emotional assessment of its merits as well as a critique of the potential shortcomings, while contextualizing it both within the narrow scope of this project and the larger Porsche zeitgeist. What, this isn't how normal people approach decision making?





In addition to playing JoAnn Fabrics all week I took the car out for a 5 hour circuitous drive to clear my cluttered head, gather some data and tune the car a bit. At this point I have the car running just about as good as I can get it without a proper dyno- Jamie's approach was masterful and aside from getting the stink eye from some homeowners along the road I have been using, everything has gone really well.



It just so happens that this Wednesday I'm taking the day off to bring the car to a dyno and Megasquirt tuner to have the final once-over done. I'm excited to see how close I came and where he makes changes.



In addition I made some other purchases for yet another winter project. This one is more experimental and as such I'm not yet ready to share but I'm super excited about it and think that if I can manage to pull it off it will be pretty darn neat.

[chrisbalich]

Julian,

Am I correct that the 5 textile choices are solely for recovering the new seats?

If that is correct, my vote is a contrived mess.

Without having the fabric samples in hand, I vote against 4 & 5 as they look very plush. I associate that plushness with being hot. As we drive these cars the most during the warm/hot months, I always try to be mindful of ways to stay comfortable whilst behind the wheel.

I also associate that plushness with a lack of durability. All those soft, fuzzy fibers (again, to me) look like they'll shed all over you and pill and pull and be otherwise unruly. This probably speaks to my allergenic sensitivities, but fuzz is a non-starter for me.

I will admit that it appears 4 & 5 are zoomed in more than 1-3. (enlarged to show texture?) This may be the source of all my feelings; and if so, I will gladly adjust my 'hot take'. (My gut says they look like grey oatmeal.)

It's worth noting that wool can be sensitive to the combination of heat and moisture. Specifically why we don't dry wool clothing in the dryer during laundry. I'd really hate to see your inserts shrink/distort because your car isn't 100% water-tight and then it gets hot in the summer sun. **I'm thinking road trip here, not day to day living.

#2 looks like the tweed found in my door cards. I've specifically decided to not use it for seats as it's not pleasant to touch. I reckon seats are in constant contact while you're in the car. For these reasons, I'm out.

#1 is my second choice. The more I type this reply, the more I'm realizing that of the five choices presented, I prefer the variegated colors more than the 'solids'.

Based on the info I have at this time, I vote #3. The nap provides a subtle pattern, while the weave stays tight and smooth. A larger sample may prove to look cheap next to the others while #1 may surpass it as my current fave. IDK. It's so hard to get a feel for textiles when you can't actually feel them.

/rambling

[Showdown]

Good food for thought as always, Chris.

These are the seats. The fabric will replace the pepita, and the rest will be brown leather, some perforated, some not.



All of the fabric is industrial grade upholstery so it'll be plenty durable but I do hear you about the fuzzies and how that may be an issue- it may be too textural and plush for a car interior.

Also, of note- I've been eating gray oatmeal for breakfast for the past few weeks so... parapraxis?

The more I look at them the more I think that #2 is the right balance of neutral with a bit of texture to create interest without having a dominant narrative.

Good talk!

[shoooo32]

Two thoughts; 100x yes for dumping the stock comfort seats. They're anything but comfortable and straight trash in the twisties. If you like the look of your samples and want to keep with tradition, maybe take a look at the factory SC berber fabrics. They have a similar look, breathe well and are very durable.

[jac1976]

Originally Posted by chrisbalich

Based on the info I have at this time, I vote #3. The nap provides a subtle pattern, while the weave stays tight and smooth.

Which direction with the cord?

[Hulley]

I'm thinking #2 or #3 for the reason mentioned already, leaning towards #3 if I saw it in person.