Ultimate ST thread

[HughH]

Baudett
i dont think I have any build sheets for an early M491 car there were not very many made only a handful in 1970
However when a well known 1970 M491 car was offered for sale this was the description

You can see that the process in 1970 is to start with a "normal" M471 ST and then send it to the race shop to have it upgraded to a group 4 or special GT M491 car
This explains some of the detail and interestingly the price differential between a normal car (in 1970 that would have been a "lightweight homologation S") and a ST with the M471 options and then a M491 track car


"According to accompanying Porsche certificates, this car offered here was delivered through MAHAG/Munich on 01. March, 1970 with the following features in the original color blood orange:
ST sports equipment M491
Locking differential with locking factor 80 M220
Roll-over bar M420
Immediately after delivery and before approval for road service, the first owner, Mr Hans Braun from Nuremberg, had the car modified to “Group IV Special GT“ by the Porsche racing department at factory 1 and equipped with following features:
230 hp racing engine 2.3 l (911/22) with Weber carburetor 46 IDA
Widened plastic fenders and bumper bar in front
Widened fenders in rear
Plexiglass screens
Multi-part transmission ratio
110 liter fuel tank
7‘‘ and 9‘‘ racing wheel rims

With this specification, the 911 ST group IV special GT with a curb weight of only 930 kg reached a power/weight ratio of only 4.04kg/hp (in comparison: Porsche 911 2.7 RS 1973: 5.1kg/hp; Porsche 911/991 Carrera 2014: 4.94 kg/hp), remarkable even for today's standards.

The extra price for the “normal“ 911 ST sports equipment M471 was DM 1.250 back then. Accordingly, a 911 ST in sports equipment had a catalog price of DM 31,230. According to its first owner, the vehicle offered here had a price of ca. DM 50,000 in 1970. The price also shows the difference between the 911 ST models from serial production and the models of the group IV special GT, modified by the racing department."

[davep]

Hugh, did you determine the VIN of this car? I note it is one of the special 930 kg cars.

[HughH]

Yes Dave. I will send it to you separately. I am not sure the owner would it known

[_gonbau]

Is there any Porsche documentation that states that an M471 vehicle must be used to create an M491? Information that says this exactly. From my point of view, a 471 vehicle for the circuit is not the same as one for rally, so it seems strange to me to add the same modifications for either. From my perspective, vehicles that were for the circuit and (if it's true, which I don't know) were based on an M471, would not have been raised in height, for example, for rally performance. From what I understand from the comments, the same M471 that was used in rallies was used in circuits by adding the 2.5L engine (M491) with the same rally modifications that the M491 would include? For me, it needs a closer look because I don't quite see the use of M471 (as such) in circuits along with M491.
I think the Z program vehicles from 1972 fit better on a list of M471 chassis.
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"Is there any Porsche documentation that states that an M471 vehicle must be used to create an M491? Information that says this exactly"
I think the answer to this is in the 1970 document where they mention that there is a 911 S/T prepared in the factory AND THAT IN ADDITION it could be prepared for... I think that when it says "in addition" it is as you indicate, an over-equipment on a 911 S/T, I suppose it will be related to M471 although it is not entirely clear to me that when naming the S/T in that circular, it is being named "m471"
*If it is clear to me, looking at the title SportausFurung


Even so... I still wonder if there are M491 vehicles with the inscription T on their sheet (I think not) except for the Z-programm 471+491. So from my point of view I still think that if that annotation does not exist, perhaps this list of 21 - Z-programm should be called something else.

Regarding the car you mention, I seemed to understand that for 1970 m471 meant something totally different from a sports package?

I believe that in 1972 compared to 1970, m471 and m491 definitely existed. Hence the document where it only mentions those two packages separately, perhaps in 1970 the s/T could be equipped for the circuit but I think that in 1972 where the sports equipment 471 and the racing equipment 491 are mentioned it should not include 471, and those that include it are marked with program Z, that's what that program was made for, I understand that to mix the two characteristics something that is not done according to my thinking in the famous client/career
+
Is the dead pedal on the 550 spot-welded or seam-welded? From my understanding, if the vehicle is as I believe (taken from the assembly line), it should be seam-welded rather than spot-welded. Does anyone have a detailed photo of this?
+

https://www.porsche-st.com/

A really great video

[Nimba]

Is there any Porsche documentation that states that an M471 vehicle must be used to create an M491? Information that says this exactly. From my point of view, a 471 vehicle for the circuit is not the same as one for rally, so it seems strange to me to add the same modifications for either. From my perspective, vehicles that were for the circuit and (if it's true, which I don't know) were based on an M471, would not have been raised in height, for example, for rally performance. From what I understand from the comments, the same M471 that was used in rallies was used in circuits by adding the 2.5L engine (M491) with the same rally modifications that the M491 would include? For me, it needs a closer look because I don't quite see the use of M471 (as such) in circuits along with M491.
I think the Z program vehicles from 1972 fit better on a list of M471 chassis.
+
"Is there any Porsche documentation that states that an M471 vehicle must be used to create an M491? Information that says this exactly"
I think the answer to this is in the 1970 document where they mention that there is a 911 S/T prepared in the factory AND THAT IN ADDITION it could be prepared for... I think that when it says "in addition" it is as you indicate, an over-equipment on a 911 S/T, I suppose it will be related to M471 although it is not entirely clear to me that when naming the S/T in that circular, it is being named "m471"
*If it is clear to me, looking at the title [B]SportausFurung

Even so... I still wonder if there are M491 vehicles with the inscription T on their sheet (I think not) except for the Z-programm 471+491. So from my point of view I still think that if that annotation does not exist, perhaps this list of 21 - Z-programm should be called something else.

Regarding the car you mention, I seemed to understand that for 1970 m471 meant something totally different from a sports package?

I believe that in 1972 compared to 1970, m471 and m491 definitely existed. Hence the document where it only mentions those two packages separately, perhaps in 1970 the s/T could be equipped for the circuit but I think that in 1972 where the sports equipment 471 and the racing equipment 491 are mentioned it should not include 471, and those that include it are marked with program Z, that's what that program was made for, I understand that to mix the two characteristics something that is not done according to my thinking in the famous client/career
+
Is the dead pedal on the 550 spot-welded or seam-welded? From my understanding, if the vehicle is as I believe (taken from the assembly line), it should be seam-welded rather than spot-welded. Does anyone have a detailed photo of this?
+

[B]

I think it´s the opposite. Early ST cars was based on empty T shells from Karmann that the sports department modified, therefore having lots of seam welds added.
M471/491 cars from 1972 where built with an specific built sheet already from the beginning. I think I´ve shown a picture of the dead pedal on my
-72 M491 before. It´s spot-welded and welded on before another panel is attached. You can clearly see that the panels are overlapping
on a small section, and the dead pedal is underneath, ie welded on prior to the other panel.
The same is with other detalis, like the brackets for the breather bottle in the engine compartment. It´s spotwelded and that´s only possible when the
fire wall is being built up and the roof is not attached yet. Brackets for the safety harness is also mounted inside the center tunnel and in the frame with
the reinforcements attached with spotwelds. It´s the same on Carrera RS and RSR. Early ST´s had these brackets seam welded on the outside.
That is what I seen on various pictures. Exception is 911R (it has a spot-welded dead pedal)
This is from my -72 M491 car. Note the highlighted part

[recarno]

@gonbau: Thank you very much for the interesting letter from January 19, 1970. Have you also shown page 2 or perhaps here in the forum? thank you very much for the answer. regards uwe

[_gonbau]

Attachment 600781Attachment 600782
"re 911 (sports version)Dear all,
Porsche's sports department has the aforementioned design vehicle available for test drives in order to provide interested parties with optimal technical-sports advice. Anyone seriously interested in this vehicle can contact the responsible employees, Mr. Staudenmater and Mr. Barth, at the Stuttgart-Zuffenhausen plant for such a test drive and sports advice (Tel. 0711-8203 330 or 319).
We recommend that the respective specialized salesperson actively participate in these contacts and, if possible, accompany the potential customer on their visit to Stuttgart. It must be expressly noted that the sports department cannot provide any information regarding the delivery dates of these vehicles.
The basic equipment of the 911 S sports version can be found in the general brochure. Subject to approval by F.I.A., the vehicle can be additionally prepared for Wattbeverb as follows:

1. 2.2 litersThe engine is approximately 2.3 liters bored, with special pistons and cylinders, Carrara 6 rocker arms, a special Sprite valve, special exhaust, and a special clutch, delivering approximately 230 horsepower.

As with previous Westbevecbeautes, all wheel pasta can be replaced, and different transmission ratios are possible for each gear and .com, as well as different internal transmission ratios, and a special differential.
"
In this text, they are referring to the "911 S-T" model, which seems to be a sports version of the Porsche 911.
Regarding the statement about having a "design" vehicle available for test drives, it likely means that the factory has a specially prepared vehicle for potential buyers to experience and "sample" what they would be paying for. In any case, it is referring to the "911 S-T" (sports version).
¿The circular mentions modifications for lightweight on the chassis.??
As for the unclear delivery dates of "those vehicles," Porsche might be referring to the vehicles that the prospective buyers will test and purchase ("S-T" version). The uncertainty in delivery dates could be due to production schedules or other factors.
When mentioning the equipment for these sports version cars, it's likely that they are using a brochure, possibly the one often seen for sport-purpose vehicles.??
+
on the other hand, 013 was built on a T chassis as far as I understand, VIN numbering etc match an S, how do you know that a T chassis was used to make the prototype vehicle?
Attachment 600786
https://www.bonhams.com/auction/2272...ne-no-6320023/

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Attachment 600796Attachment 600797

Hereee post

[matteo68]

Hugh

I’d say your post #963 is the definitive statement on the 911 S competition versions from ‘70 through ‘72, and whether M471 or M491 and hopefully clears up any lingering confusion for all of us.

Thank you for that.

[matteo68]

I have the fzgs for all of the 21 and all of them except 0495 and 0550 do NOT have a handwritten T after 911 S…

[matteo68]

Is there any Porsche documentation that states that an M471 vehicle must be used to create an M491? Information that says this exactly. From my point of view, a 471 vehicle for the circuit is not the same as one for rally, so it seems strange to me to add the same modifications for either. From my perspective, vehicles that were for the circuit and (if it's true, which I don't know) were based on an M471, would not have been raised in height, for example, for rally performance. From what I understand from the comments, the same M471 that was used in rallies was used in circuits by adding the 2.5L engine (M491) with the same rally modifications that the M491 would include? For me, it needs a closer look because I don't quite see the use of M471 (as such) in circuits along with M491.
I think the Z program vehicles from 1972 fit better on a list of M471 chassis.
+
"Is there any Porsche documentation that states that an M471 vehicle must be used to create an M491? Information that says this exactly"
I think the answer to this is in the 1970 document where they mention that there is a 911 S/T prepared in the factory AND THAT IN ADDITION it could be prepared for... I think that when it says "in addition" it is as you indicate, an over-equipment on a 911 S/T, I suppose it will be related to M471 although it is not entirely clear to me that when naming the S/T in that circular, it is being named "m471"
*If it is clear to me, looking at the title SportausFurung


Even so... I still wonder if there are M491 vehicles with the inscription T on their sheet (I think not) except for the Z-programm 471+491. So from my point of view I still think that if that annotation does not exist, perhaps this list of 21 - Z-programm should be called something else.

Regarding the car you mention, I seemed to understand that for 1970 m471 meant something totally different from a sports package?

I believe that in 1972 compared to 1970, m471 and m491 definitely existed. Hence the document where it only mentions those two packages separately, perhaps in 1970 the s/T could be equipped for the circuit but I think that in 1972 where the sports equipment 471 and the racing equipment 491 are mentioned it should not include 471, and those that include it are marked with program Z, that's what that program was made for, I understand that to mix the two characteristics something that is not done according to my thinking in the famous client/career
+
Is the dead pedal on the 550 spot-welded or seam-welded? From my understanding, if the vehicle is as I believe (taken from the assembly line), it should be seam-welded rather than spot-welded. Does anyone have a detailed photo of this?
+

https://www.porsche-st.com/

A really great video

The website seems to require a password? Is that correct?