'67 Fiat 124 Berlina - build and maintain

[grrrdot]

With the Turbo Diesel I have an MSG5 transmission that is also Guibo Free and it has not posed a real problem except for possibly a tad more telegraphing of rode noise through the drive line. May put a little more stress on the pinion and ring gear without the snubbing provided by the silent coupling but I do not push the car with a lot of aggressive hole shot take offs.

Good to know. I've only got a 1608 so even a "hot take-off" isn't that impressive. The car also still has the original torque tube rear which as far as I can tell is known for messing up the pinion, I'll have to keep an eye out for that.

[DieselSpider]

With the Turbo Diesel I have an MSG5 transmission that is also Guibo Free and it has not posed a real problem except for possibly a tad more telegraphing of rode noise through the drive line. May put a little more stress on the pinion and ring gear without the snubbing provided by the silent coupling but I do not push the car with a lot of aggressive hole shot take offs.

Good to know. I've only got a 1608 so even a "hot take-off" isn't that impressive. The car also still has the original torque tube rear which as far as I can tell is known for messing up the pinion, I'll have to keep an eye out for that.

The 1.8 L OHC Turbo Diesel is very torquey and with the 4:30 gearing can start of easily in second gear so like many pickup trucks you are tempted to skip first gear altogether and once the boost is up from a hole shot out of first will chirp the tires in second gear. For a Diesel its a rev'er with a 5,500 rpm redline due to the OHC design but I an fearful of the stress that the extra torque can put on the drive line especially when I tow my boat (small 550 lb sailboat) and its pulling like a tractor.

[Special]

Too bad you are so far away .
I wish I had a friend like you close by - we have a lot in common.

I've seen your build! Very inspirational! You've got much more of an eye for design than I do.

Together we could take over the world

[grrrdot]

Woah been awhile since I updated this. So much has happened! Lets finish off with the transmission then I'll get into the other stuff.

I got around to fully installing the transmission cover for the interior. I'm bummed because I ended up cutting out much more of the transmission tunnel than I needed to. It became one of those things where you cut a little here and then a little more and then its too much! All that said I'm excited about how I attached the cover.

For a few years I have been reading about auto-makers using epoxy to attach non-critical parts to cars. I wanted to try this out as burn through with Mig welding is real and a little stressful. After a bit of reading I found that the epoxy technology has continued to improve and automakers are now using it for structural car components!

So, of course, I picked up a tube
https://www.3m.com/3M/en_US/company-us/ ... 165&rt=rud

If your not familiar this stuff is pretty cool. It covers the entire seam to hold the part on. This helps with NVH and reduces the chance of air and water leaks. (and rust) Depending on the stresses the part will see it can be used with clamps, rivets or even spot welding. Clamps is likely enough for a trans tunnel cover on this car but I decided to used some sealing 3/16 pop rivets as I'm not interested in owning a bunch of weird shaped clamps.

I followed the directions but think I used too much ( as you can see ) this is all covered by sound deadening and carpeting so thats fine




I think this wraps up the T5 install, it works great is quiet and the highway rpms are AWESOME, even for my 1608 and I get better fuel mileage.
If I was going to do this again on a Sedan I would probably just cut the shifter box down, it would mean less trans tunnel work and it would be easier to find an off the shelf shifter.
For any Spider owners I imagine this trans would be an overall easier install. The 124 Spider trans tunnel already has clearance and the Mustang remote shifter would allow specific placement of the stick to match up exactly with the center console. That said if anyone else is interested in trying out a T5 transmissions I've posted the 3D files for the transmission and driveshaft adapters on git hub here:
https://github.com/guerdat/ClassicFiat124Parts

Happy to accept pull requests for any other Fiat related 3D drawings out there!

[grrrdot]

Hi again,
Soooo IDFs sound great and the performance is better than a single carb but I'm a little tired of chasing the flat spot around and me and the garage smelling like gas all the time.

So, I've decided to just go full ITBs. To keep the car down time to a minimum the plan is to substitute a Microsquirt unit in for the Megajolt Lite Jr. This way I could re-use some of the wiring from the MJLJR and the mounting location, get the Microsquirt working just for ignition first and then swap out the IDFs for ITB's.

Last time I messed with this stuff was when I installed Megajolt v1.0 in my now gone '79 124 Spider. That was a crazy experience. It all worked but the tuning software was really rough, I had to solder resistors in all kinds of weird places, one of the capacitors exploded while I was driving on and on.
I have to say Microsquirt is a dream compared to that! I bought the unit with the extended wiring harness. All the wires have clearly printed text on them, it uses a modern connector and the unit is so small! Amazing!

I also picked up another weatherpack bulkhead connector where I'll run all the non-ignition related wires through and wired that all up.


Even with IDF/ITBs there is enough MAP signal to use for ignition timing. MegaJolt has the MAP sensor on-board so I would need to do something about that. From what I've read most people still use the external GM 1 bar map sensor which is this rather large box that's mounted remotely with a vacuum hose. I wanted something a little more discrete so tracked down GM part number 55573248. This unit is used on some LS engines and is the only unit I could find that attaches directly to the manifold with a BOLT and a tab, all the others of this style use only tabs. So I pulled off my vacuum log and drill a few mounting holes for it:


If anyone else is using this style MAP it does not use the same range as the external style so you have to adjust the settings in Microsquirt. Also pay special attention to the pigtail, its a little different from other units.
From what I could find the correct MAP range values are 128.14, -0.31. Using this works great for me and is accurate when compared to what the internet says the baro is for NYC, cause the internet is always right

Microsquirt also supports an expanded ignition map when compared to the MJLJR. I want to take advantage of this and improve the current setup. I had seen Digiplex specs and curves in other posts but they were all for shared plenum setups. Turns out the Ritmo Abarth 130 TC has both dual carbs and a MED408 digiplex ignition! It took me awhile but I managed to find a Czech or Polish set of spec sheets for the Digiplex 401, 402, 406, 408 and 411.
Here is the 408, you have to use the line numbers in the top right to understand the mm/hg and then its advance on the Y axis and RPM on the X.



Last hurdle is that the way Megsquirt and Digiplex view vacuum are different. From what I can tell one measures the vacuum in the manifold and the other the difference to outside, they also use two different units so after a bunch of converting I was able to translate the digiplex map point by point into the Megasquirt map.

[grrrdot]

Decided to pick up this thread again and start cross posting between this forum and other forums. Just to catch this thread up I finished the ITB megasquirt install and have ~5000mi on it now. I get around 30mpg out of the car and it pulls really well for a stock 1608. With ITB mode and megasquirt there is one spot where the map transitions between using the MAP and the TPS for fueling that I can’t exactly optimize so I just leave it a little rich.

Since I always need a project I decided to install a rack and pinion setup.

I picked up a steering rack for an Omni and some tie rod ends from a Lancia Delta (QR1819S M14x1.5 thread) and after some measurements it became clear that wouldn't work. The inside tie rods that came with the rack were 9/16-18 thread and too long.
Moogs site has inner and outer tie rod specifications and after some measuring I’ve landed on EV323 for the inner tie rods which thread a little over half way into the Lancia outer tie rods.

Next obvious issue is that the setup wouldn’t work with my headers. The header I have is the two part tubular type and there was enough room to take a quick 60 deg bend where the upper and lower sections used to connect.

And then I just wandered he two pipes down between the rack and firewall, I think I used a 30 and 15 deg bends to get down to a merge collector under the car.

It took awhile to figure it all out and was great practice. The welds looked horrible so I ended up smoothing things out a bit. Here it is installed, fits really well between the frame rail and trans. While I was at it I also installed a catalytic converter should keep the exhaust stink down. Overall it’s about 1.5” longer than the original headers from what I read that would move the power band down to a lower rpm, doubt I’ll notice!
The whole header is one long piece and its easy to get in and out of the car, I think easier than the previous design!


After taking a bunch of measurements I cooked up a few versions of an adapter plate. The original idea was to mount it using two of the threaded holes in the crossmember. I started with cardboard and move up to more and more dimensionally stable materials. Here is the wood version.



After getting the rack in the car it became obvious that the rack input shaft would need to be shortened, I cut and welded mine but you can buy an Omni rack with a shortened input shaft probably easier.

[grrrdot]

Continuing on with the project I found a little tidbit on t124 about fore / aft placement.

The rack is 42mm from the xmember and 32mm above the bottom of the xmember. all dimensions are from the middle of the rack as the back lip on the bottom of the xmember is curved. Still hoping to post some photos.

oops, my last post has an error. The dimensions are from the centre of the lip on the curved rear bottom side of the xmember. (not the rack as I stated).

That puts the rack just behind straight. I used one of those construction laser lines to line up the wheels and then line up the rack across the steering arms. This is as straight as I can get it. The whole car is a little wonky from previous accident(s) / age so not sure there is a “perfect”.


After that started I working on the steering shaft. This Sedan has a one piece steering column which turned out to be great. I had to drill a new hole in the firewall down and toward the center of the car and I mounted a helical bearing on the firewall. It all fits and turns without interfering with the brake pedal.



There is still a little slop in the whole assembly though. The one piece column only has a single bearing supporting the shaft so I’ll need to address that somehow in the future.

There was just too much flex for me with just a bolt up plate. I toyed with adding more bolt holes, which could have helped. I really wanted to feel confident about this staying put so I decided to create my own mounts modeled after what Fiat did. Then I used the final template I created to hold everything in place for gluing ( Impact Resistant Structural Adhesive ) and welding into place. Lastly I put a coat of paint on. I don’t have a good picture but the mounts wrap around and attach to the cross-member in two places. I’m confident this is not going anywhere.




I’ve put about 500mi on the car with this setup and it works well. Steering is instantaneous, it took awhile to learn not to move the wheel back and forth to go in a straight line.
There is some bump steer at highway speeds when going over very rough pavement. The car toes out on rebound and compression so I think the tie-rods are too short. I also miss the quick ratio when driving around town so I’m thinking I could shorten the steering arms at the spindle. The Lada crowd seems to do this as well. First, I need to figure out exactly how long the lower A-arms are then I can dial in the tie-rod length.