Early production volume calculations - 1977-78
08-24-2011, 11:24 PM
#16
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Thanks for all the info, guys. I updated my first post to reflect some of this, most notably. Aug. '78 production changeover.
I read you Erkka about PET x-referencing RoW vs. US. Hard to say whether the change happened at the same time for each. But the numbers are close anyway.
More that likely, the difference is between linear math estimate, and non-linear actual production.
To your point Landseer, we would need a pretty broad VIN/build date sampling to plot a proportional curve. Across the whole 15 months. This is doable for US cars.
Biggest issue I see is the difficulty in plotting a curve for RoW, since no build dates were marked on the cars. And RoW made up a majority of total sample required.
I read you Erkka about PET x-referencing RoW vs. US. Hard to say whether the change happened at the same time for each. But the numbers are close anyway.
More that likely, the difference is between linear math estimate, and non-linear actual production.
To your point Landseer, we would need a pretty broad VIN/build date sampling to plot a proportional curve. Across the whole 15 months. This is doable for US cars.
Biggest issue I see is the difficulty in plotting a curve for RoW, since no build dates were marked on the cars. And RoW made up a majority of total sample required.
08-25-2011, 01:24 AM
#18
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AFAIK '79 MY production started in 08/78. Model year did almost always change in late summer of previous calendar year. Only exceptions were M718 option US GTS.
Austen book tries to give true model year info but it has many mistakes. Long book and few other sources have calendar year info which is really not useful in determing how many cars were made each model year.
PET information for part changes can be possibly used to give timeline what cars were on production line at same time. For example clutch center shaft and torque tube changed in middle of '78 MY some time in fall of 1977.
92881 00753
92882 00054
92882 09522
Above were last VIN's to use early style setup. If change was done at same time for all markets it can give pretty good idea how many ROW cars were made at the time. Some other part changes have clearly been done at different times for different markets. For example fuel pump and hose related changes do no make sense if they were done at same time.
Austen book tries to give true model year info but it has many mistakes. Long book and few other sources have calendar year info which is really not useful in determing how many cars were made each model year.
PET information for part changes can be possibly used to give timeline what cars were on production line at same time. For example clutch center shaft and torque tube changed in middle of '78 MY some time in fall of 1977.
92881 00753
92882 00054
92882 09522
Above were last VIN's to use early style setup. If change was done at same time for all markets it can give pretty good idea how many ROW cars were made at the time. Some other part changes have clearly been done at different times for different markets. For example fuel pump and hose related changes do no make sense if they were done at same time.
08-25-2011, 09:26 AM
#19
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BTW Rich`s black VIN sticker is part no. 928 701 112 07 so they were going thru versions very quickly. Mind you my `88 is ... 20. I have no idea why or even if it is remotely significant.
08-25-2011, 09:33 AM
#20
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I think plotting everything we know along a timeline, from 76 through 79, would be an interesting excercise.
That type of triangulation is something that is core to research in all fields, and its being done in a way now by Jim.
Getting it into a more standard and comprehensive format would engage more people.
Gotta believe that Porsche or exPorsche folks could then add to it and fill / correct more aspects.
Knowing when a clutch shaft change was made by trans# may be the key to something else. Plot it all, especially this type of stuff. I like the idea of mining all our vin numbers, as well as mining PET and TSB,s and WSM. Its out there.
Fun stuff.
That type of triangulation is something that is core to research in all fields, and its being done in a way now by Jim.
Getting it into a more standard and comprehensive format would engage more people.
Gotta believe that Porsche or exPorsche folks could then add to it and fill / correct more aspects.
Knowing when a clutch shaft change was made by trans# may be the key to something else. Plot it all, especially this type of stuff. I like the idea of mining all our vin numbers, as well as mining PET and TSB,s and WSM. Its out there.
Fun stuff.
Last edited by Landseer; 08-25-2011 at 01:44 PM.
08-25-2011, 10:40 AM
#21
Instructor
Sorry, no pics of my tag, they're not there anymore...but my MY79 is 9289101062...it appears after an early repaint all of the factory tags except for the one up front in the engine compartment were removed.
08-25-2011, 01:32 PM
#22
Been selling Twinkies on Ebay,
have some extra cash right now.
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have some extra cash right now.
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I edited my original post (#9) to include sticker info... more clues?
I will delete this message in a couple of days.
I will delete this message in a couple of days.
08-25-2011, 01:48 PM
#23
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Thread Starter
Not sure how relevant that sticker's p/n may be though. Let me know if you guys who've expressed interest figure it out.
08-25-2011, 03:00 PM
#25
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Generally speaking it was finished being built on February 22, 1977.
That was the build date used for all the pre-production press cars. Some may have been finished sooner than that, although it all came down to the wire and interior was rushed to completion. They didn't even get the seats from Recaro until Feb. 12th!
And you're right, it's doesn't have an OE build sticker in the door jam.
That was the build date used for all the pre-production press cars. Some may have been finished sooner than that, although it all came down to the wire and interior was rushed to completion. They didn't even get the seats from Recaro until Feb. 12th!
And you're right, it's doesn't have an OE build sticker in the door jam.
Last edited by Jadz928; 08-25-2011 at 04:13 PM.
08-25-2011, 03:21 PM
#26
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Here's one for you....
Did you know later a prototypes (W12), done at stage 2 construktion (almost all production mfg.) was still being built, while the 12 press car were being built and readied? Finished March 1977.
Oh you know it! Recently, Porsche was kind enough to let me know the earliest 928 fitted with an Automatic Transmission was 928 810 0035.
08-25-2011, 11:03 PM
#27
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Hey Jim,
I'll be happy to put it all in a spreadsheet to produce a timeline. Just post or pm me a list with all of the build dates and vin's. We can also add things like tranny, color or just about anything else.
Eddie
I'll be happy to put it all in a spreadsheet to produce a timeline. Just post or pm me a list with all of the build dates and vin's. We can also add things like tranny, color or just about anything else.
Eddie
01-17-2012, 08:56 AM
#30
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Another data point.
Pulled the seats on 78 RoW #579, VIN 928 810 0579
Seat mfg date of Sept. 30 1977. So my guess is #579 was built in early Oct. 77.
This is interesting me, and will have to look a little closer as to how this fits/affects my original estimate.
Seat mfg date of Sept. 30 1977. So my guess is #579 was built in early Oct. 77.
This is interesting me, and will have to look a little closer as to how this fits/affects my original estimate.