Duck/NoDuck

[1QuickS]

I can't imagine the intestinal fortitude it took to get a 2.2 S above 130 mph on the autobahn in 1971

Consider the balls to average 130 MPH for 96 hours in a 911R in 1968 including time to replace front suspension.

[1QuickS]

According to Paul Frere in The Porsche 911 Story

• 2.7 RS lift over front axle with air dam at 152 MPH with air dam is 77.3 lb
• 2.7 RS lift over rear axle with ducktail at 152 MPH is 93 lb
• If front dam is used without duck tail then lift over front axle is 70.6 lb and over the rear axle is 320 lb!!!

Also noted was the decrease in side wind sensitivity as center of air pressure moved further behind front axle.

Aerodynamic benefits were noticeable beginning at 60MPH.

[911MRP]

This is repeating what has been said elsewhere, but from reasonably extensive personal experience, above 100 mph, and certainly above 120 mph, you want mit front- und heckspoiler! I have no idea whether the front air dam or ducktail matters more (I have friends that will swear by an even more aggressive front splitter and the tea tray tail), but above three digits the car is frightening to drive without and lovely to drive with. I can't imagine the intestinal fortitude it took to get a 2.2 S above 130 mph on the autobahn in 1971, but then maybe it was normal back then for cars to wonder around at speed (I don't believe anyone had the patience to get a 2.2 T above 130, and I say that as an owner of two of them!).

All of that said, the cars look better without, imho. Plus, the ducktail and license plate panel get soiled promptly, quickly attaining the brownish sheen of a heavy smoker's teeth, who is only casually familiar with a toothbrush never mind the occasional visit to the dentist.

… due to the extra forces generated by the RS front and rear pairing several sunroof components were required to be strengthened — don’t recall the exact date or part numbers of the couple of small (plastic? parts involved offhand.

Following the early work by Porsche such as that well documented development of the aerodynamic parts specified for the road going 73 RS that’s being discussed here, Porsche continued take aerodynamics very seriously. The scary stories from the drivers of the earliest 917 until the aerodynamics were attended to are very well known — these racing specials preceded the 73 RS.

While it is an owners prerogative to do what they wish if they prefer aesthetics over function but it’s probably reasonable to assume that the solution Porsche put on front and rear on the limited edition homologation special for a year at the end of the long-hood era of interest to this forum is not a bad way to go. While a few 73,RS did choose ducktail delete preferring aluminium for example the customer who first bought this example photographed yesterday …
Attachment 603190


…the majority in 73 (eventually) got that RS combination the engineers had worked to develop despite having to wrestle with the German regulators for rear duct aim to be approved and yielding to the French regulators for the front when they required the use of one from the S. If memory serves me well I posted something here before showing the form used in front of RS (with provision for an oil cooler) has some advantages to the S front — can’t recall what it said or if significant.


Steve

[Chris Pomares]

Mini Duck and splitter. I'm not sure how much the mini Duck makes, but the front splitter made a huge difference on my SWB car. 90 to 100 mph with a slight crosswind the car is totally planted. Before it was a hovercraft.

[928cs]

… due to the extra forces generated by the RS front and rear pairing several sunroof components were required to be strengthened — don’t recall the exact date or part numbers of the couple of small (plastic? parts involved offhand.

Following the early work by Porsche such as that well documented development of the aerodynamic parts specified for the road going 73 RS that’s being discussed here, Porsche continued take aerodynamics very seriously. The scary stories from the drivers of the earliest 917 until the aerodynamics were attended to are very well known — these racing specials preceded the 73 RS.

While it is an owners prerogative to do what they wish if they prefer aesthetics over function but it’s probably reasonable to assume that the solution Porsche put on front and rear on the limited edition homologation special for a year at the end of the long-hood era of interest to this forum is not a bad way to go. While a few 73,RS did choose ducktail delete preferring aluminium for example the customer who first bought this example photographed yesterday …
Attachment 603190


…the majority in 73 (eventually) got that RS combination the engineers had worked to develop despite having to wrestle with the German regulators for rear duct aim to be approved and yielding to the French regulators for the front when they required the use of one from the S. If memory serves me well I posted something here before showing the form used in front of RS (with provision for an oil cooler) has some advantages to the S front — can’t recall what it said or if significant.


Steve

The "Beirut" RS! Glad that it is still unrestored.

And an M471 without ducktail must be a unique combination, or very unusual.

[72targa]

The "Beirut" RS! Glad that it is still unrestored.

And an M471 without ducktail must be a unique combination, or very unusual.

Always a great story…

https://www.early911sregistry.org/fo...aces-in-Beirut

[Cliff]

72/73 rear suspension points are different from all the previous versions! afaik

[skinnerd]

Looks great without the duck.
Although I had one on my 73 for the majority of the 35 years I owned it.