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

[Showdown]

Day 32


Well that wasn’t the vacation I was expecting.

The week before leaving, my Mother’s boyfriend bulged a disc, I tore a muscle in my back and oh, Yellowstone closed for the first time since the 80s.

The morning before we hopped on a plane to Salt Lake City and a 4 hour drive to Island Park, Idaho (just south of West Yellowstone and the Western entrance to the park) torrential rains and snowmelt washed away several roads and made the park unsafe for visitors. The damage was extreme and unlike anything before it. Climate change is a real *****.
In any event, we made lemonade as best we could. Aside from not seeing the park we actually did just about everything we wanted to do. I hiked from 6000ft to just over 10,000 to the peak of Sawtell Mountain and then to over Mount Jefferson. It was a long day and part of it was through unexpected snowpack but the views and experience of being alone in the mountains were truly breathtaking. I also saw some Poontang. Literally. The FAA radar station atop Sawtell is named Poontang.

We rode horses into the wilderness, went whitewater rafting, lots of hiking, saw a berserk rodeo, saw bald eagles, bears, moose, tons of deer, and generally reveled in the raw wilderness that’s so far away from Chicago life. When asked what they’re favorite part of the vacation was my 6 and 8-year-old replied; “the bunkbeds”

But I digress, nobody’s here to hear my vacation so I’ll get on to the main course.

When I left the car was tantalizingly close to being put together and ready to start. After spending Wednesday and Thursday scrambling to get back up to speed at work I took Friday afternoon off to do some work on the car including the application of some vinyl.

I know, vinyl!? But hear me out. It’s a $40 way to test out different liveries without committing to anything in paint just yet. Maybe I’ll change it every year, maybe not. Maybe I’ll find one I love and put it into single stage… who knows. Anyhow, I put the vinyl on the hood and rear bumper, took a step back and decided that I quite like it.

In addition to wrapping (haha) up some of the eternal work on the body I spent some time in the engine.

A while back, before I started all the body work, I removed the ITBs (I got really good at this chasing air leaks and making improvements!) and bench sync’d them with a shop vac and synchrometer on advice from Jonny and good lord was it easy. I can’t imagine doing this fully with the engine in and running; the RHD adjustments must have been made for a child’s hands!

I set the static timing, calibrated all the sensors, and said a little prayer to Saint Butzi, the patron saint of idiots who think they should be working on old 911s.

I turned the key and instantly the car started. The RPMs jumped to 2500 and so I had to dive into the engine and work those ITBs some more. After a bit of tinkering (damn those tiny adjustments!) I got them all synched to 4 on the synchrometer which resulted in a smooth idle of about 1000.

I have to set the timing but I’m having a hard time understanding that procedure and am hoping someone can point me to a primer for idiots. My car, a 77 S is set to have +/- 2 degrees TDC @ 950-1000 RPM… Check. At 4000 RPM I think it’s supposed to have 25 degrees BTDC as that's the mark on the pulley wheel but there's nothign in the tech specs about it. My dizzy is bottomed out clockwise so there’s that too. Currently I’m running the car with fixed timing at 0 degrees. If I try to run it any other way, I get blowback through the ITBs and the idle and engine are much rougher. At fixed 0 degrees the engine idles well and there’s no popping through the ITBs.

I started it up, let it warm up, and then put it into gear and backed it out into the waiting sunshine. Feeling good about the way the car was running I decided to take it around the block. It felt so damn good to drive the car again!

I was able to get and keep the idle at around 1000 but the AFR was at 10. Grossly rich and running like gas wasn’t $6 a gallon. I took a look at the tune Al provided and decided to start lowering the entire table until I got an idle somewhere around 13.8-14 at idle. I had to lop off 20 points off the table to get it to not be painfully rich. This tune was bonkers!

I took the car out with the laptop and tried to adjust the fuel table to keep the AFR as close to 13.8 as possible. Very hard while driving, but I was able to get it running smoother and smoother by monitoring the AFR table and pulling over to adjust accordingly. There was some stumbling and hesitation below 2500 RPMs but above the car felt really strong- it was also still filthy rich at 10:1. One odd thing, as I pulled into the garage, the idle surged to 2000, then 2500, then 3000. All the linkages were rock solid and tightened down completely. Hmm. I'll have to see what that's about.

Unfortunately, TunerStudio crashed and I lost the log of that 20 min drive. aargh!

I’m going to have to take an afternoon this week to gather another tune to analyze.

I also I emailed a few Megasquirt tuning shops to make an appointment. I want to get the most out of this car and one really needs a lot of experience and a dyno for that; neither of which I have. Luckily in Chicago we have plenty of shops that specialize in tuning aftermarket EFI and were all too happy and excited to get a vintage Porsche in their shop.

Oh, I just got my Check22 confirmation... so now I really have to get this POS running well!!

Some lousy iPhone sunshine photos to prove it actually left the garage! In the sun, all of the little paint issues totally disappear, which is nice.

[chrisbalich]

This is one of the updates I've been waiting for!

Excellent progress. I'm curious which shop you're using for tuning.
I may need to borrow their expertise to get my car dialed the rest of the way in...

[Showdown]

I found two. I spoke with both quite extensively and they're both really familiar with MegaSquirt and the local racing scene. The work with tons of modified cars and Porsche didn't seem to phase them one bit. It also didn't incur any P tax which was a nice bonus. Time-wise they're about the same from me, distance wise the one in Antioch is much farther so I'm probably going with RC, just in case I don't make it, I'd rather be in the city than out in the country for tows and whatnot...

I'm hoping to get to one of them within 2 weeks, at least before August. I'll update, of course.

RC Autoworks
www.RCautoworks.com
7434 W 90 St
Bridgeview, IL
60455
708-599-5884

And

Dyno Source Performance
20009 W. State Line Rd | Antioch, IL 60002
justyn.bell@dynosourceperformance.com
773.209.9015
www.dynosourceperformance.com

[Jonny042]

Originally Posted by Showdown

Day 32



I have to set the timing but I’m having a hard time understanding that procedure and am hoping someone can point me to a primer for idiots. My car, a 77 S is set to have +/- 2 degrees TDC @ 950-1000 RPM… Check. At 4000 RPM I think it’s supposed to have 25 degrees BTDC as that's the mark on the pulley wheel but there's nothign in the tech specs about it. My dizzy is bottomed out clockwise so there’s that too. Currently I’m running the car with fixed timing at 0 degrees. If I try to run it any other way, I get blowback through the ITBs and the idle and engine are much rougher. At fixed 0 degrees the engine idles well and there’s no popping through the ITBs.

Great update!! Car looks wonderful.

Lets dig into the timing. Do you have a CDI+? I've forgotten. EDIT - Sorry that's a stupid question. You have a megasquirt and you've locked out the distributor?

[chrisbalich]

Originally Posted by Showdown

I found two. I spoke with both quite extensively and they're both really familiar with MegaSquirt and the local racing scene. The work with tons of modified cars and Porsche didn't seem to phase them one bit. It also didn't incur any P tax which was a nice bonus. Time-wise they're about the same from me, distance wise the one in Antioch is much farther so I'm probably going with RC, just in case I don't make it, I'd rather be in the city than out in the country for tows and whatnot...

I'm hoping to get to one of them within 2 weeks, at least before August. I'll update, of course.

RC Autoworks
www.RCautoworks.com
7434 W 90 St
Bridgeview, IL
60455
708-599-5884

And

Dyno Source Performance
20009 W. State Line Rd | Antioch, IL 60002
justyn.bell@dynosourceperformance.com
773.209.9015
www.dynosourceperformance.com

You're a scholar and a gentleman.
Now if I can get everything to run correctly, I'll give them a call to squeeze out the HPs.

[Showdown]

Originally Posted by Jonny042

Great update!! Car looks wonderful.
You have a megasquirt and you've locked out the distributor?

Thanks Jonny!

MegaSquirt with MSD Streetfire and Pertronix, Clewett wires, new plugs.

The dizzy is locked as far clockwise as I can turn it- the lock bolt is all the way on the right side of the slot.

I set the static timing to cylinder 1 and tried to follow Al's instructions on setting and checking the timing with the MegaSquirt and using the trigger wizard but I got stumped. (I'v never timed an engine BTW...)

With the MegaSquirt timing set to use table or fixed and at 10 degrees (the default) I get a choppy engine and blowback through the ITBs. Blue and orange flames are super cool, but not inside the engine bay!

With the MegaSquirt timing set to fixed and at 0 degrees, the engine instantly starts to purr and is super smooth. The blowbacks are gone and it's smooth through the higher RPMs

Per the tech specs my car needs +/- 2 degrees TDC, which I can get with the MS at 0 degrees and the dizzy locked all the way clockwise. My timing light confirms that. So that's a win.

I understand that I need to set the timing at 4000 RPMs and I *think* my car needs 35 degrees BTDC but the tech manual is blank on this. There is a notch and stamp at 35 degrees BTDC so that's where I get that number.

So I need to set the timing at 4000 RPMs but given that my dizzy can only go CCW I'm guessing that may be a problem?

I guess what stumps me is what to do with the MegaSquirt. Leave it at 0 degrees or use the table?

[mepstein]

I think it’s a really cool car but for me, there’s too much going on with the white, gold, grey and black. The wheels look like black holes or almost like it’s on a chassis dolly and the grey doesn’t let the shape of the body flow from front to back. I’m all for trying something different but I’m not feeling it here. I do like the gold accents in the front. It reminds me of the 906. Terrific car though and I sure wouldn’t kick it out of my garage.

[Jonny042]

Originally Posted by Showdown

Thanks Jonny!

MegaSquirt with MSD Streetfire and Pertronix, Clewett wires, new plugs.

The dizzy is locked as far clockwise as I can turn it- the lock bolt is all the way on the right side of the slot.

I set the static timing to cylinder 1 and tried to follow Al's instructions on setting and checking the timing with the MegaSquirt and using the trigger wizard but I got stumped. (I'v never timed an engine BTW...)

With the MegaSquirt timing set to use table or fixed and at 10 degrees (the default) I get a choppy engine and blowback through the ITBs. Blue and orange flames are super cool, but not inside the engine bay!

With the MegaSquirt timing set to fixed and at 0 degrees, the engine instantly starts to purr and is super smooth. The blowbacks are gone and it's smooth through the higher RPMs

Per the tech specs my car needs +/- 2 degrees TDC, which I can get with the MS at 0 degrees and the dizzy locked all the way clockwise. My timing light confirms that. So that's a win.

I understand that I need to set the timing at 4000 RPMs and I *think* my car needs 35 degrees BTDC but the tech manual is blank on this. There is a notch and stamp at 35 degrees BTDC so that's where I get that number.

So I need to set the timing at 4000 RPMs but given that my dizzy can only go CCW I'm guessing that may be a problem?

I guess what stumps me is what to do with the MegaSquirt. Leave it at 0 degrees or use the table?

Ahah! So, when I say "distributor locked", I mean is the advance mechanism disabled.... Has it been? The distributor shaft is split in two parts, and the realtuonship between the is adjusted based on rpm and a set of centrifugal weights indie the distributor.

Do not drive this car until you know what is going on with the timing. You're a smart enough guy to figure it out for yourself based on the information available.

I say that because following someone else's (including mine) directions may get you in trouble. A "tuner" is not necessarily going to be able to help you. And at the end of the day you need to understand what's going on with the motor for yourself.

I suspect the car runs fine at 0 timing because the distributor is doing its job. But only the guy holding the timing light knows for sure.

[Jonny H]

^ What he said.

There was a thread on here recently with people tying themselves up in knots over CDI+ timing. Same thing unfolding again here with MSD. Essentially, the fundamental concepts of ignition timing need to be understood. Whatever ignition unit you have - it is just the tool to facilitate that timing.

You need to learn the rules of the game. Otherwise you're just moving the pieces at random hoping to win.

Start with what is meant by 'locking' a distributor and why we do that when using the electronic ignition.

p.s. I rather like the gold decals!

[Showdown]

Originally Posted by Jonny042

You're a smart enough guy to figure it out for yourself based on the information available.

You are completely wrong.

I don't have the slightest clue as to what I'm doing. Really.

[Jonny042]

Originally Posted by Showdown

You are completely wrong.

I don't have the slightest clue as to what I'm doing. Really.

You've got some catching up to do. I got my first air cooled VW dunebuggy when I was 12 (40 years ago) .... and I've been laying awake at night thinking about this crap every night since!!!

The point is I had to read a book to learn all about this stuff:



You have the World Wide Web!! Start reading!!:

https://www.onallcylinders.com/2020/09/11/timing-is-everything-how-initial-mechanical-and-vacuum-advance-work-together-to-make-power/

[Jonny042]

Originally Posted by Jonny H

You need to learn the rules of the game. Otherwise you're just moving the pieces at random hoping to win.

But it's not a game you are running around in a minefield!!

I think the basic problem is that people don't fully understand that too much ignition timing will put holes in pistons and break ring lands, even on a relatively tame motor.

You don't want to be messing with this stuff if you don't know what you're doing. We have reached a point were a "Car Guy" can get to a ripe old age of XX years without owning a timing light, much less knowing what to do with it and what it all means. It's downright scary.

The good news, it's not rocket science, it's super interesting, and really rewarding to know. It's actually pretty simple. But you need to understand how an internal combustion engine works (suck, squish, bang, blow), that cams turn half the speed of the crank, and the basics of spark timing.

[Jonny042]

PS - I suspect that reading and memorizing the well written Classic Retrofit CDI+ manual (available at their website for free!) will give you a heck of a shove in the right direction.

[Showdown]

Thanks for the hand holding fellas, I suspect if you're not already Fathers, you'd make fine ones.

I have to admit that I'm not as much of an idiot as I profess to be; self-deprecation is a cultural pastime for my people... That said, I wanted an adventure that would push and teach me and this hasn't disappointed.

--

My main confusion was with how to make the dizzy and the MegaSquirt play nice and sync with each other; which one to adjust, which to give priority to, etc... Sometimes the internet, and the overload of information in general just makes a mess of relatively simple things.

Turns out my approach and rational was correct and after a bit of research and emailing Al, I was and am on the right track. His system doesn't use a locked dizzy but does allow for adjusting the timing table if necessary; a hybrid approach, I suppose. It works for Al and that's all I need to know for now.

My engine requires basically 0 TDC @ idle at 35 @ 4000. Setting the MegaSquirt timing at fixed and 0 degrees and verifying that timing with my light was and is correct. And wouldn't ya know, I did it right the first time! Hooray for this idiot.

I still have to check at 4000 RPMs; Working my way up to being that close to a spinning fan of death But barring anything out of the ordinary, I should be good to go.

Then I can start tying to figure out my fuel map and not spewing gas all over the neighborhood.

The good news is that I can pull, clean, and replace all the plugs in about 20 mins. Practice makes perfect...

[Jonny042]

Good for you! Keep that timing light hand and check it often! I wouldn't go past 32 degrees BTW. That $6 a gallon gas isn't what it used to be....

FWIW I fully believe you can tune your car 100% yourself with an AFR gauge, the dyno won't help you with drivability, cold starts, highway cruise, etc. and will be an expensive lesson. I wouldn't think you are quite ready for it yet. Sounds like you're getting the bugs out of it already. Keep up the great work!!

[Showdown]

I do want to learn as much as I can but I think that having a professional tuner look it over (while I’m asking lots of questions) is a totally reasonable approach and will hopefully be a small price to pay for some real masterclass experience.

There’s nothing like watching someone work- I’m learning that lesson on the other side with a new assistant at my work and seeing just how valuable it can be.

Plus, I figure that with gas that expensive, the cost of a tuner tightening up the fuel map will pay for itself toute suite!!

[Jonny042]

Originally Posted by Showdown

I do want to learn as much as I can but I think that having a professional tuner look it over (while I’m asking lots of questions) is a totally reasonable approach and will hopefully be a small price to pay for some real masterclass experience.

There’s nothing like watching someone work- I’m learning that lesson on the other side with a new assistant at my work and seeing just how valuable it can be.

Plus, I figure that with gas that expensive, the cost of a tuner tightening up the fuel map will pay for itself toute suite!!

Fair enough! All good points.

[chrisbalich]

Originally Posted by Showdown

...Working my way up to being that close to a spinning fan of death ...

If you're like me and oft find yourself wearing a hoodie whilst working on the car, I recommend tucking in the hood strings...or designating one hoodie for working on the car and pulling them altogether.

I don't always remember, but the 'tink' of the knarps on the strings hitting the moving fan is a terrifying reminder that I'm in harm's way.

[Showdown]

Good lord that would make me ***** my pants.

I don’t know what I was doing but my knuckle grazed the center of the fan and I nearly jumped out of my shoes; and that was at idle!

[chrisbalich]

Originally Posted by Showdown

Good lord that would make me ***** my pants.

I don’t know what I was doing but my knuckle grazed the center of the fan and I nearly jumped out of my shoes; and that was at idle!

Yeah, back when I had ITBs, I spent an inordinate amount of time leaned over the engine while it was running. One of the best things about changing over to the 964 manifold is that I find myself leaning over the running engine a lot less. (specifically, not at all)