Aero developments on RSR's

[Flunder]

Hugh,

Scholarship and documentation set the bar high for this thread.

Look forward to learning more.

[911T1971]

you may be correct but if you look at how the brake ducts are attached to the original spoiler in that photo they seem to be attached relatively high at the front of the original part of the spoiler with mounting tabs that do not appear to be present in the photo below which has the full deep spoiler

Hugh,
I am by now means on your level of provided infos and did below pic post before, but FYI this is
(supposedly) another brake duct design, not on a factory car but on a private entry 72/73 2.5l Euro GT class.

[HughH]

Karim
that reminds me that we should look at the different designs of the non factory teams.

Kremer did use various front spoiler designs however i suspect that the factory team, with the resources of the university wind tunnel behind them, not to mention years of working on aero design on the prototype racers (think 917 and 908, 910 longtail for example) must have had an edge on most other teams at that stage.

I will try to dig up and post some Kremer photos, I know that the RSR had a couple of different designs although I am not sure what science went into it.

[911T1971]

however i suspect that the factory team, with the resources of the university wind tunnel behind them, not to mention years of working on aero design on the prototype racers (think 917 and 908, 910 longtail for example) must have had an edge on most other teams at that stage.

Hugh, i'm not so shure..

If you read on the 917 development and how the factory 917 prototyp was weak on its aerodynamic stabilty until the british John Wyer team came up with the right aerodynamic solution on their 917KH, one does questions the capacity of their Stuttgart wind tunnel.
It maybe was down to academic knowledge against hands-on race know-how and since Piech goal was always overall speed, the factory 917 initially lost overall stabilty and downforce.

Porsche was known to be a proud factory and they would never admit that actually privateers sometimes had the better ideas...as did May in the fifties on their 550spyder.

I rather assumed they closely watched what privateer like Brumos, Kremer and other did on the track with their 911 and -in exchange of good factory relations- often got first-hands racer know-how on 917&911 aerodynamics.

[911T1971]

that reminds me that we should look at the different designs of the non factory teams.

Some infos, I tried to be as accurate as possible...I'm shure Hugh knows them all.

Brumos Porsche, 1971(?)
Driver Gregg, 911S GT group 3



IMSA Camel GT 1973
Driver Bergstrom, 911S under 2.5l class.



Euro GT Championship 1973
Driver Haldi (Mischler), private entry 2.8l RSR

Different version (see decals) but same year:



Euro GT Championship 1973
Driver Fitzpatrick, Kremer entry 2.8l/3.0l RSR
(Kremer/Schickentanz used first 2.8l RSR and later switched to to 2.94ccm/3.0l engine capacity RSR)
Version 2.8l RSR
Start at Montlhery



Euro GT Championship 1973
Driver Schickentanz, Kremer entry 2.8l/3.0l RSR
(In 1973, Kremer/Schickentanz used first 2.8l RSR and later switched to to 2.94ccm/3.0l engine capacity RSR)
Version 2.8l RSR (before Estoril)
Start of Monthlery

Version 2.94l/3.0l RSR (probably after Estoril and with different decals)

[HughH]

Great photos Karim

I will try to post some more in the next couple of days

[HughH]

Hugh, i'm not so shure..

If you read on the 917 development and how the factory 917 prototyp was weak on its aerodynamic stabilty until the british John Wyer team came up with the right aerodynamic solution on their 917KH, one does questions the capacity of their Stuttgart wind tunnel.
It maybe was down to academic knowledge against hands-on race know-how and since Piech goal was always overall speed, the factory 917 initially lost overall stabilty and downforce.

Porsche was known to be a proud factory and they would never admit that actually privateers sometimes had the better ideas...as did May in the fifties on their 550spyder.

Hi Karim
Yes they made a mess with the first 917's, and a few other cars as well. However my point was that they had been experimenting with aero for a long time, probably not as long as Michael May but still a long time

they also had access to the wind tunnel and as photos in the RS book show had been using it on the 911 since the early 1970's (the RS book on pages 86 and 87 show experiments with tails , front spoilers and covered weather strips on an ST in April 1970). Therefore they had the capacity and obviously the interest to play with the aero. How successful they were (versus some privateers) at the end of the day is hard to tell but they did make major changes especially in 1973.

Just on that they ran 2 prototype cars at Austrian 1000 Kilometres, Österreichring, Zeltweg on 24.6.1973; R7 (car #8) in a similar fat tail that it had at le mans but a different front spoiler and R6 (car#7) with the first of the longtail designs (which evolved more at the next race at Watkins Glen).

Austria was a high speed circuit (although not as fast as Monza or Le Mans) so the comparison between two cars, both with the same engine and wide rear ends but one a longtail must have been interesting.

What is interesting to me was that there was virtually no time gap between the two cars on a track that should have favoured the longtail, The Longtail R6 qualified in 1:54.890 while The other car qualified in 1:56.650 with the top qualifiers the 3 litre V12 Matra-Simca MS670B's qualifying in the mid 1:37's.


here are some photos of both cars at the Österreichring and a close up of the tail of R6