Homologation details 911 T

[mikehump]

I am trying to find out a little more about the homologation of the race engine described in the Sports Purposes manual (the twin plug almost-906 engine). I know that a small number of 911T's were delivered with these engines for racing. Were the engines homologated for Group 3 racing in period or did fitment of these engines move the car into a different class? Any help appreciated.

Cheers, Mike

[Flunder]

Hi Mike:

It looks like the 906 engine would place the car into Group 5 for the 1968 season.

See attached page from Sports Purpose.

Tom

[chris_seven]

I don't think I agree with some of this.

The original homologation of the 911 was into Group 3 on Homologation Form 183.

Group 3 is specifically Grand Touring Cars. This homologation took place on 16-11-1964 and is why most FIA Spec Race cars use Solex carbs as the most common Class is for Period F Cars which is for vehicles up to 31-12-1965

The next Homologation of the 911 took place on 01-01-1966 and is covered by Form No. 503 This again is a Group 3 Grand Touring Car.

The 911S was originally homologated into Group 3 on 01-11-1966 and is again a Grand Touring Car.

The 911T - which we now refer to as the T/R- was homologated into Group 3 on 01-01-1968 using Homologation Form 577 and is again a Grand Touring car. Most of the special parts, 906 engine, fibreglass panels etc used on the 911R were listed in this form many of them being denoted as 'valid only for Group 4'

There is no means for a Group 3 car to transfer into Group 5.

Between 1966 and 1969, Group 5 cars were specially modified Touring Cars (Touring in this context means a Saloon car). Only cars homologated into Group 2 could run in Group 5 during this period.

If you modify a Group 3 Grand Touring cars within certain permitted criteria than it becomes a Group 4 car, which is the category that would have been used for the T/R.

The 911 was also and unusually homologated as a Touring Car into Group 2 using Homologation Form 1451 on 01-01-1966. The 911S and 911L were included as extensions to this basic form. This is why Porsche refer to Group 5 in the context of the 911S and 911L.

It is this homologation that allowed Vic Elford to contest the British Saloon car Championship in a factory 911 much to the disgust of regular saloon competitors using cars such as the Lotus Cortina.

Group 5 was changed significantly in 1970 and was used to redefine many Group 4 cars. It became a Sports Car Homologation with a maximum engine capacity of 5.0 litres and a minimum build of 25 cars - The most famous Group 5 car being the 917.

I hope I haven't made too many errors but if I have please point them out.

[911T1971]

The 911T - which we now refer to as the T/R- was homologated into Group 3 on 01-01-1968 using Homologation Form 577 and is again a Grand Touring car. Most of the special parts, 906 engine, fibreglass panels etc used on the 911R were listed in this form many of them being denoted as 'valid only for Group 4'

Below the original document I own, 14 pages.

[mikehump]

Thanks all, that is very helpful!

Karim, do you know anywhere that I can get a copy of the homologation form?

If the twin plug engine moved a 1968 911 T into Group 4 - was this the prototype class? Does anyone know what this equates to in FIA Appendix K classifications?

Cheers and thanks for all the help,

Mike

[chris_seven]

Prototypes ran in Group 6. This is the category that was used for the 911R entries in the rallies that were contested in 1967.

I am reasonably confident that a T/R with a Twin Plug 901/20 motor was used in Group 4.

The fact that the 911T was homologated into Group 3 on 01/10/1968 means that it is gong to be a Period G1 car and as regards Appendix K it is likley to be a GTS16 Class vehicle.

If you intend to build and run a car in FIA Historic Events, which as you rightly say are governed by Appendix K, then you will need an HTP.

The form that you will need to complete is quite detailed and you would need the relevant Homologation Forms to be able to complete this successfully. (If you need a copy of this form I have one I could e-mail)

An FIA Approved Scrutineer would then need to inspect the vehicle and ensure that it complied with all of the relevant details and the homolgation form.

The Homolgation Form that would be used for this check would need to be copies supplied by the FIA or your ASN and not copies obatined from other sources.

These papers would have to carried with the car to all events so buying them is worthwhile.

In the past I have filled in the forms, copied the papers and sent a preliminary set to the Scrutineer that will appraise the car and made sure that we could obtain a result before we modified the car.... just a thought.

[mikehump]

Thanks Chris - that is very helpful information. I have another car with an HTP but have never looked at the process of getting them issued as it came with the car.

I have got a copy of the homologation forms (thanks Karim!!) and will have a look at them over the weekend.

Cheers, Mike

[mikael]

Great information in this thread!

Does anyone have the 547 homologation papers from 01.11.1966 that puts the 911S in Group 3? I would be very keen to get a copy.

[chris_seven]

I have the following forms.

They cost a significant amount to buy and collate and maybe have some value.

I could scan and put on a DVD if there was any interest.


Homologation Form 183 Porsche 911 1991cm^3 GT Dated 16-11-1964

Homologation Form 204 Porsche 912 1582cm^3 Group 3 Dated 01-08-1965

Homologation Form 207 Porsche 911 2687cm^3 Group B Dated 01-03-1982

Homologation Form 1451 Porsche 911 1991cm^3 Group 2 Dated 01-01-1966

Homologation Form 503 Porsche 911 1991 cm^3 Group 3 Dated 01-01- 1966

Homologation Form 547 Porsche 911S 1991cm^3 Group 3 Dated 01-11-1966

Homologation Form 577 Porsche 911T 1991cm^3 Group 3 Dated 01-01-1968

Homologation Form 607 Porsche 911T 1991cm^3 Group 3 Dated 01-01-1969

Homologation Form 608 Porsche 911S 1991cm^3 Group 3 Dated 01-01-1969

Homologation Form 609 Porsche 911E 1991cm^3 Group 3 Dated 01-01-1969

Homologation Form 637 Porsche Carrera RS 2687 cm^3 Group 4 Dated 01-01-1973

Homologation Form 3005 Porsche 911S 2195cm^3 Group 3 Dated 01-01-1970

Homologation Form 3011 Porsche 911E/T 2195 & 2341cm^3 Group 3 Dated 01-04-1970

Homologation Form 3025 Porsche 911S 2195 & 2341cm^3 Group 3 Dated 01-04-1970

Homologation Form 3053 Porsche Carrera RS 2687cm^3 Group 3 Dated 01-07-1973

Homologation Form 3060 Porsche 911 2687 cm^3 Group 3 Dated 01-02-1974

Homologation Form 3061 Porsche 911S 2687 cm^3 Group 3 Dated 01-02-1974

Homologation Form 3062 Porsche 911SC 2687 cm^3 Group 3 Dated 01-02-1974

[RennTyp]

I'm interested!