924Board.org

[Cedric]

Good work with all the upgrades, nice that the pinto bolt fit well!

Whats the plans for this season, just drive around, or try something more advanced like autocross (with the wheel on this time maybe ) Will the car stay here or in the south?
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1980 924 Turbo
www.instagram.com/garagecedric/

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[Raize]

Not sure if it was posted but is the gearbox in this one the snail or the Audi box?

What brake issues are you having? I did my own brake upgrades with the inspiration of yours which are now just finished so might be interesting to compare notes.

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Inspection done!
Clear for another 24 months

Putting the turbo-stuff back on tonight!
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/Magnus, Stockholm Sweden
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Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

[morghen]

nice! enjoy!
Hope i can say the same soon.
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Supercharger and EFI kits
https://www.the924.com

[Beartooth]

Very good, it's got to be a relief! I'm so glad I don't have to deal with any of that; obviously there are people who either have no clue mechanically or no ability to think through consequences, and that's why vehicle inspections are mandatory in many places. But for us, we all probably have a good idea of what's a real hazard and what's just nitnoid stuff. I can register any old heap and be legal, but I won't take a car on the highway until I'm confident in the tires, brakes, steering, and suspension - which is a large part of the reason my 931 didn't see the road until over a year's work (intermittently) had been done to it. Anyway, I bet the car feels like a slug without the turbo! Any idea what went wrong with the brakes? It sounds like the pads didn't bed in and glazed over instead, but I have no idea what could cause that. Hopefully the new pads do the trick!
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1980 931 diamond in the rough

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Winter fun, fixing nagging things that is really annoying.

There is an exhaust drone around 3000 rpm. Trying to fix that with a better quality rear muffler, also bigger. Its not a loud exhaust otherwise, just makes it unpleasant on longer drives.



Looks the same.


Hopefully that will make the issue smaller.

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/Magnus, Stockholm Sweden
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Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

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I've been slowly working on a G31 gearbox for the ratrod.
I had a 911/915 LSD I could fit to it also.





Had to rearrange the disks inside the diff and change the direction of the ramps to fit the 924, or a front engine car really.
A 911s diff is set up to lock up more on engine braking to stabilize the cor into a corner, while most other cars lock up on power to grip up under acceleration.
Its the ramp that puts pressure on the clutch disks making them lock up. I also moved around the individual disk to decrease the lockup from 80% to 40%, you essentially takes one of the friction disks out of play... Its all in the set up manual for the diff (Kaaz diff, Japan)





Decided to strip down the gearbox to to install a one piece bearing retainer and have a look at stuff.




Here I found trouble...
The dog teeth on 1st gear was compleatly worn down.
Not only that you can basically call them hens teeth because you can't find replacements... So here it stopped for quite a while until Cedric mentioned that he had replaced his long ago an still had the old ones and they were in much better shape than mine! Lacking pictures of that...



Hopefully it will soon be ready for installation. Torque tube gear linkages are ready.
I just need to get the fly wheel balanced and machined. Only unknown is how the clutch release bearing will interact with the new twindisk clutch.
I need to get some time on a lift in my other workshop.
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/Magnus, Stockholm Sweden
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Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

[Cedric]

One mans trash is another mans treasure Especially when it comes to G31 parts

How did you do with the ramps, just swapped around acceleration and braking side? What will the end result be on this diff do you think for the ramps, how much lock on braking? Since its mostly a road car i think its good to not have so much locking i general, it did grip up surprisingly well without the diff.

that poor G31 has no clue what its going to have to suffer through
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1980 924 Turbo
www.instagram.com/garagecedric/

[924RACR]

Now that you're prying into the details... how do you go about changing the ramp angles, looks to me like you'd need to remachine that housing or replace it with one with the desired angles?

How about spring rates, do those want changing too?

Very interested since a certain one of my projects (day job) is pursuing some changes in that area, the design is virtually the same I believe, and I don't usually get to get my eyes on those details..
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Vaughan Scott
Webmeister
'79 924 #77 SCCA H Prod racecar
'82 931 Plat. Silver
#25 Hidari Firefly P2 sports prototype

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You just flip around the piece with the ramps and it will work in the other way.
It switches from 1.5 reverse to a 1.5 standard.

It could be set up as hard 100% locking (as it came), medium 65% or soft 35%.

I set it up to 65% as that was the recommended setting for street and auto-x.

I actually don't know how the diff locks up. if its 65% on acceleration and something less on breaking. Or if its 65 on braking and more like 100% on the ramps. The original ZF diff with 40% lockup didn't really have any ramps.

The Kaaz USA guy was very interested in how I fit a 915 diff in a 924, he didn't realize the 931 had a special gearbox using 915 pars

The Kaaz diff is pretty high quality with 6 (3 disks) friction surfaces per side, more than the original ZF.
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/Magnus, Stockholm Sweden
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Porsche 924 -79 NA, EFI and Turbo.
Porsche 931 -79
Porsche 911 -77, 3.2 Targa
Porsche 911 -69, 3.6, Coupe

[Beartooth]

Very interesting to see the guts of the G31! I'll be there with you sooner or later... I still can't believe how well mine has held up, and how well I've adapted to driving it, despite seemingly no 1st gear syncro left (and probably dog teeth as bad as yours), and 2nd not much better, and shifter bushings that may no longer even exist. When the car does come apart, the transmission will probably be the first thing I'll go into, because finding some of those parts could be a long-term process. One or two pieces (1st/rev slider, I think, is one) may have to be sent to a specialist who welds and re-machines the teeth - and I'm not sure I want to know what that will cost! Someone worth reaching out to if you haven't already is CMS (cms@californiamotorsports.net).

I've got a quote saved, and it includes the 1sst gear dog ring, so they may have them. 2nd and 3rd as well - $250 each a couple years ago... The other things on the quote were 2nd/3rd slider ($470), 1st syncro ($160), 2nd and 3rd syncro ($210 each), and another $100 for a lock nut and seals. Total was about $1900, and that doesn't include the 1st/rev slider that I'll almost certainly need too... I wish it were like the transmission for my Explorer that I just went through, on which I replaced a cluster gear, input shaft, bearings, syncros, 5th/rev slider, 5th gear, reverse gear, and some shims and seals and such, for a grand total around $500. If wishes were horses, beggars would ride though, as I remember hearing back when. Just one of the joys of working on something built by the thousands versus millions.

Looks like I need to start saving up - or sell a car - before I start on that one! Anyway, hopefully you can find some good enough pieces to make it work ok without spending a pile on it! I'm also interested in what you're doing with the LSD, although I'm lucky and my car came with one. I might want to play with making it more aggressive though. I've never even worked on a differential, so tinkering with an LSD would be all new to me.
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1980 931 diamond in the rough

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