Decklid Air Scoop - Help Identify & Source

[Scotty2H]

I ran accross a sale ad for a car with an interesting decklid scoop. I've long wanted something just like this but have never seen anything like it.

Does anyone know anything about these scoops? A search didn't really turn anything up. Anyone make a replica? or have a line on a pile of them in a barn somewhere (a guy can dream right?)

1967 911 S Coupe

[gazzerr]

I have never seen that before so my guess is custom. That is one sweet car.

[rwest]

Very interesting, though I wonder if air passing over the grill helps remove some heat and having the air rammed into the compartment would be more than needed?

[Reiver]

Originally Posted by rwest

Very interesting, though I wonder if air passing over the grill helps remove some heat and having the air rammed into the compartment would be more than needed?

I wonder the same...things that often look 'common sense' when aerodynamics are the subject are often not.

Had Porsche used anything similar on their 911 based racers? If not why not.

It seems (totally guesswork) that the grill underneath would slow air in the inlet creating a pressure that would create an air dam?

[kent olsen]

When you look at it you would think that's a great idea, but. I remember years ago an article from Porsche showing the air flow over the car and effects of all the different tails. As the air comes off the roof it doesn't want to follow the slope of the rear deck. The ducktail helped a little, the whale tail even more and now you see race cars with the rear spoiler way up in the air.

In this race application I think the fan would help pull the air down towards the opening but I don't think you'd get any ram effect. I would think it might cause overheating in a street application

[mickey356]

Maybe there is some custom tin work underneath to assist with air flow/movement?

[Helix8]

It would be interesting to see this in a windtunnel test

[422flat6]

This car was featured in July 2017 Panorama magazine. It's a custom scoop, from this car's racing days in the 60's. Very cool story.

See here: 1967 911 S Coupe

[merlinfe]

I've seen this car race at the Daytona HSR events. It's really quick and this scoop didn't seem to hurt THAT much.

-Steve

[Jack Stands]

They used to be sold back in the day (70’s) by a variety of vendors (Performance Products comes to mind),but must not have worked well or I’m sure we’d see more of them these days.

[Scotty2H]

Thanks all for the information. While I wonder about the performance, I like the aesthetic and would be inclined to give it a go and monitor oil temps. I'd be suprised if it had a noticable impact. I always like the scoops present on the 997GT3/RS and this give a similar look in line with the style of the older cars.

The search continues!

[racer]

This is for cooling, not down force. This would be more important if the car was running minimal or no front oil cooler (no shots of the fenderwells to be sure) but being able to get more cool air into the engine compartment would help the engine run cooler.. Not sure a "ram effect" would be noticed given no signs of routing underside to the carbs or cooling fan, but a nice "period" piece.

[ian c2]

Is it not there to help eliminate dust entering the “top-half” of the engine bay on dusty tracks ?
I think I remember them being used on European 911 rally-stage cars .

[Quicksilver]

It is a cool vintage detail on a cool car but it isn't a good example of smart aero. Airflow won't follow a curve past 11° before the airflow detachs so there won't be any laminar flow going down the back of the window. The airflow at the grill is going to be turbulent and a lot of it is going to flowing forward at the grill surface.

A ram air intake won't work on a 911 unless you build a snorkel just for the intake and extend it up into the airflow. If you had some sort of real ram effect at the grill you would only be improving the cooling and unless you were cooling deficient it wouldn't help. (Actually "over cooling" reduces power output. It will increase longevity though.)
The only possible power increase from ramming cooling air into a 911 is if the "help" reduces the power consumption of the fan. Obviously that would be extremely minimal so no one has ever chased after it.

[stownsen914]

I recall seeing these scoops advertised back in the 70s.

Agreed with what Quicksilver said about the lack of laminar flow over the back of a 911. A small scoop like this wouldn't be able to scoop much air at that height. And consider too that the opening of this scoop is substantially smaller than the area of a 911 decklid grille, so I'd argue that this scoop probably decreases airflow to into the engine bay.

Scott

[msort81]

From the Porsche Parade Monterey in '73 thread over at ESR.

[kent olsen]

I remember racing SCCA and Trans-Am in Portland back in the 70's. Aero was just beginning to show up. Walking around the pits after everyone went to the hotel we found things like, more windshield rake and a skin under the car to smooth out the airflow. Some where deemed illegal but allowed the in following years

The best one was a windshield washer pump that pumped water into the front brakes. We tried that during practice and holly cow what a difference that made!! The concern was what if you ran out of water and didn't realize it, you would go off the end of the straight like a rocket. We took it off also and it was never allowed afterwards.

[msort81]

[racer]

Wouldn't this image show that air does run down the back of a 911? So it would run right down into the scoop?

Again, its not for aero.. and no doubt, subsequent Duck tail/carrera/whale tails were willing to sacrifice cooling for lift management. But a scoop like the OP had might be lighter and just as effective on engine/oil temps vs the weight and complexity of running lines and a cooler to the front of the car. Don't really know.. just speculating..

[midnight911]

on my 84 carrera, i had IROC wing for track use and the presence of the wing cooled the engine a little better than regular deck rid.