Ultimate ST thread

[Leirbag]

from PORsport on Instagram :

"1971 Werks ST arrives home. Next a trip to the painter where it will get its original Blood Orange color"





https://www.instagram.com/p/C94hdEwpD6m/

[myflat6]

this is a fascinating thread. incredible amount of knowledge being poured into this thread from this community. so i am stepping way outside my understanding and knowledge with a question. it appears that both short stroke and long stroke versions were used.
i am trying to understand how/if this would influence homologation? is it just the displacement capacity that is part of the homologation, and not necessarily how the displacement is achieved?

[HughH]

baudett
I dont have time at present to respond to all of the points you made
however on the ST v SR v S there have been a lot of names thrown around over time
the official name as homologated is 911S Group4 It can only be 911S as if it was called anything else there wound have had to be 500 identical units made for Gp 4 and 1000 for Gp3

so they were homologated as a 911S and that is what they were known as officially. they could also be built in either Gp3 form, or like the 2.5M491 cars in Gp 4 form. Note that M491 Gp4 cars existed in 1970 and 1971 as well (and 1973 and beyond)

As to your comment about a T handwritten on a 2.5M491 build sheet here is an example with 0550's



and on that classic driver quote about the 1970 car being T's that is misinformed
ALL ST's or what ever you want to call them had a vin number that designated them as an S ie in 1970 it was 911 030 xxxx NOT a "T" shell which would be 911 010 xxxx although in practice the major differences in ALL the shells (apart from competition modification) is almost zero. The differences are in the engine fitted and the trim levels. So what was really the case with the 1970 and other cars is that they were based on the spartan trim levels that existed for the T and was homologated for the S in the 1970 MY so they could continue on using the spartan trim and the lower weight that that afforded

[_gonbau]

**By the way: I think I shouldn't skip this step. I will comment on the photo as if I had never seen it before. Sometimes, questions 'educate' knowledge...
Perhaps, a brief explanation when showing a document of this weight will be MORE THAN IMPORTANT, understanding that most forum users have not seen this document. In this document, you can clearly see the T designation next to the S. You can also observe the kommit number with prefix 099 and the subsequent sequence 510001. It is understood that, given the motor versuch it carries, the sticker with its engine number is written in pen... Or did ALL these vehicles have the engine number written by hand? According to an article I read some time ago, this vehicle was cataloged (I think) as the second S/T made. The S/T 550 is understood as a 'low-medium' VIN number, but if we look at its knee number, I think we can understand that this chassis was taken and the numbering was delayed since the stamping was done at the end... correct? And, it was not done by the factory itself but by the sports department with its VIN stamping machine. Was the same practice applied to the Z-program vehicles?
What is interesting about this vehicle is that, according to what we see, Z-program vehicles 471+491 could potentially have the T between Coupe and S. There are other Z-program vehicles that should be published here, and also certain sheets of vehicles PURELY m491 should be published to see if any contain the T annotation. In my thoughts, when I was considering this vehicle, I don’t know why I thought it was made on the 'normal' line and then... transferred to the sports department, but I'm not sure why I thought that.
As an additional note... There is a 'defect' on that sheet that is different from many others. I believe that this lies in an extremely important fact, in a simple detail that seems insignificant but might actually be more significant than it appears.

I mean PURELY m491. One of those vehicles from the list. Not a Z-program.

Regarding what you mentioned about the T, it's what I think, what you're indicating. Therefore, that needs to be clarified out loud, as it's something that continues to be stated from 'A very high place.

rom my point of view, the list of the 'S/T' (which I wouldn't consider to be S/T) should be a bit shorter, excluding the Z-Programm vehicles that include the M471. In my opinion, this is what makes a car an S/T and not an M491.
Therefore, this vehicle you're showing could indeed have the T designation, according to what I think. Other M491 vehicles shouldn't have it. That's why I'm asking. To clear up that doubt.

PD:



I hope you enjoy these documents as much as I have. There are many interesting details, some related to the kommit and its division, etc., etc... I hope the 'expert' eye enjoys them. And as we can see... Pbase is still being written..."

[928cs]

I can only advise to buy this issue, if you are seriously interested by the 911 ST:
https://000magazine.com/shop/010/?_g...MjAxNjU3MTU1OQ..

[_gonbau]

Is that the book where Huhgg participated?

[928cs]

Is that the book where Huhgg participated?

Yes, it is

[HughH]

*
I mean PURELY m491. One of those vehicles from the list. Not a Z-program.

Baudett

To my knowledge the Z option is just another series, like M options, but more specialised (as a group of competition items put together in this case)

The area that did this work, the customer race department, evolved into the sonderwische area, which still exists, and has always used Z codes for special options and groups of options

so all you are looking at with that Z code is a group of specialised options including M491 and M472 and probably a lot of other unrecorded things that form a package of competition items that were included in the 1972 2.5S M491 cars

there are NO pure M491 cars, it is an option that takes the normal M471 competition spec cars up to "race version" cars In almost all cases I believe due to the extensive modifications for racing, none of these cars were eligible or cleared by the factory as able to be registered as road cars (however from time to time people were able to get individual approval for registering the cars)

[928cs]

To my knowledge, Z-Ordnung means zusätzlich Ordnung or additional order, and by definition is used for everythnig that can not be ordered with the usual order guide.

The codes and meaning can change from one car to another, or not.

[_gonbau]

Baudett

To my knowledge the Z option is just another series, like M options, but more specialised (as a group of competition items put together in this case)

The area that did this work, the customer race department, evolved into the sonderwische area, which still exists, and has always used Z codes for special options and groups of options

so all you are looking at with that Z code is a group of specialised options including M491 and M472 and probably a lot of other unrecorded things that form a package of competition items that were included in the 1972 2.5S M491 cars

From my perspective, there are indeed "pure" M491 vehicles, given that there already exists the M471+M491 program, which is what you suggest these vehicles are but noted only with the M491 option without Z-program. If this were the case, why, having the program that should go on each M491 sheet, is only M491 used? It would make sense if vehicles with the Z 471+491 program did not exist. But since they do, why not use the same Z program for those vehicles? The only thing that occurs to me is that they might indicate different things and that "from my perspective" M491 would not necessarily have to include 471. This is what I think.

there are NO pure M491 cars, it is an option that takes the normal M471 competition spec cars up to "race version" cars In almost all cases I believe due to the extensive modifications for racing, none of these cars were eligible or cleared by the factory as able to be registered as road cars (however from time to time people were able to get individual approval for registering the cars)

Where does the information come from that the M491 included the M471? Is it documented in any internal brochure? As I understand it, the M491 was the racing version and the M471 was the sports version according to the documentation. At what point does it state that the M491 should include the M471?

When discussing racing modifications, it should be noted that these vehicles were manufactured in STANDARD with those "racing modifications" as ONLY M491, not subsequently. So, I think they would have known the performance before manufacturing, as indicated in the documentation provided earlier, which says that M491 vehicles cannot be used on circuits, whereas M471 vehicles could be used in all sporting contexts. Have you seen any M491 vehicle documentation that includes the letter T? It would be interesting to resolve this doubt... From my perspective, I believe that each S/T was noted on each vehicle's documentation, like with the Repsol or the 550...
I find it hard to believe that in some documents it was simply forgotten to note it, etc. Therefore, I think the factory knew how to differentiate between an S/T and an M491 2.5L for circuits and thus did not make certain annotations on those vehicles (according to my perspective). I think the factory used some vehicles that were M471 (S/T) and added M491 to them, but that doesn't lead me to believe that vehicles that were "purely M491" followed the same process. Rather, it was different, which is why the 471+491 program was not assigned to them. They were "purely" M491 vehicles and were thus mounted separately (on the assembly line you mentioned in the sports department).
Regarding the M471 and Z-Programm vehicles, do you know if those vehicles started on the normal assembly line? I seem to recall you had mentioned something related to this. I would be happy to be corrected and to see an M491 document with the designation of T.

To my knowledge, Z-Ordnung means zusätzlich Ordnung or additional order, and by definition is used for everythnig that can not be ordered with the usual order guide.

The codes and meaning can change from one car to another, or not.

If this is as you indicate, then it is understood that the M491 vehicles were, as Huhgg suggests, standard... but where is it indicated that this standard, which does not need the Z-programm, includes M471? It seems to me that I've seen it somewhere in the documentation, but I'm not sure if what I'm saying is accurate.

Regarding the variation or lack thereof of the Z number, in Stkarey's book there is a Z program number that is repeated for several (I believe two) vehicles, which leads me to think that some Z programs were reused for certain vehicles.
+

My understanding i that all of the 21 cars in 1972 were built completely from scratch in the customer race department (unlike in previous years and possibly for the 1972 factory "ST's" where they started life on the normal production line) This even extended to the vin stamping of the 21 cars which was done on a totally separate machine to the production line vins). this is another unique feature of these 21 cars