Active cooling air flaps for the Porsche 911 (991.2)

Conditions for opening and closing the radiator shutter

Well, some of you may be wondering why I'm suddenly talking about the 991.2 generation now, when the 992.2 Porsche 911 has already appeared on the market.

However, it bothers me so I can't help it (I'm being stubborn ^^).

My favorite black Carrera is the 991.2 model, and I'd like to talk about the shutter-like parts in front of the left and right radiators on the front of this black Carrera...they are called flaps, and look like they can be opened and closed by flipping them up and down (this has changed from the 992.2 GTS model to a vertical one).

The official name of this part seems to be "Active Cooling Air Flap," and as the name suggests, it is movable rather than fixed.

However, I have never actually seen this flap open or closed, and as far as I can remember, almost all Porsche 911s (991.2 or later generation) parked in parking lots have this flap in the "open" position.

Well, then when exactly do you close your doors?

So I was curious and decided to look into it.

What are the active cooling air flaps in the Porsche 911 Carrera?

Thankfully, someone had put up the 991.2 Carrera's "2017 Service Information Technik" (section 2.8.4) online, so I checked it out. Thank you!

Here it is:

First of all, the explanation of what this active cooling air flap is is as follows:

• It is designed for circuit driving and directs a large amount of cooling air to the left and right radiators.
• Off the track, where there is less need for cooling, air flaps can be used to restrict the airflow, reducing the amount of air passing over the car and therefore reducing drag.
• The cooling air flaps in the 2017 911 Carrera provide electrically controlled cooling at all times, on demand.
• Not only does it improve fuel economy in the NEDC cycle, but the benefits are especially noticeable in everyday driving.
• The cooling air flap is optimized based on the cooling requirements of the engine, transmission and air conditioner, the energy loss caused by the air flowing inside the vehicle, and the operating status of the electric fan.
• A system that calculates the optimal combination of flap opening and radiator fan operation in real time, taking into account the efficiency of the entire vehicle and depending on the driving conditions at the time.
• Flaps can be set to 5 different positions (open, closed and 3 in between) for maximum efficiency

I see, I see.

When to open and when to close

The next thing you may be wondering is when exactly does this flap close and when does it open?

The conditions are as follows:

[When the radiator shutter opens]

• In SPORT PLUS mode, PSM Sport Active, or PSM off
• When the vehicle speed is less than 15km/h or more than 170km/h
• When the outside temperature is over 45°C
• When a mobile device is connected and the vehicle speed is 120km/h or faster

[When the radiator shutter closes]

• Coasting
• When cooling is not required

I see.

So, in normal mode, when you're driving normally around town at speeds between 15 and 170 km/h, the lights are actually closed in most cases!!

Let's take a look at the Porsche passing by next time ... ^^

If we look again at the image in the service information, we can see that there is something called a "Servo motor for cooling-air flaps" near the active cooling air flaps.

This adjusts the flap's opening and closing in five stages (controlling its movement).

And today. It's not a black Carrera (is it different?), but I went for a drive in a 992.1 Carrera T and came back. *The detailed opening and closing conditions may be different between the 991.2 and 992.1.

I happened to stop the car...or rather, right after I stopped it, I checked this flap, and I was like, "Hmm? Oh? This is it!"

I understand?

It's a little hard to see because the lights are still on and it's raining, but I think it's not completely closed, but a little closed, around "the third level out of five?"

"Oh, so it was working properly. I didn't know. I've only ever seen it open."

Thinking that, I was happy to see that the flap seemed to be closed, and with a grin on my face, I parked the car in the parking lot.

Then, after I parked the car completely in the parking space, I looked again and thought, "Oh no, the flap seems a little closed," but nope.

See! It's completely open!!

great.

So that's how it moved. This photo was taken 2 minutes after the first photo.

In other words, I think that since I was just driving leisurely around Tokyo in normal mode this time, the conditions of "coasting/no need for cooling" were met, and so the flaps were "closed" while I was driving to reduce air resistance.

Now it slowed down as it entered the parking lot, and this time it said,Vehicle speed is less than 15km/hSince the car met the conditions of "coasting, or when the car is traveling at a speed of 170km/h or more," when I first saw the photo, the flaps, which had been closed while the car was coasting, were in the process of opening as the car's speed dropped below 15km/h. However, since the car was then simply parked in a parking lot, the speed remained below 15km/h, so the flaps were fully open.

In that state, I parked the car and turned off the engine, so I think the shutter (flap) was left in the open position.

This is why the flaps on all Porsches parked in parking lots are "open."

Wow, I get it, I get it.

Finally, here’s a video (0:18) showing the flaps going up and down:

I'm sorry for telling you this long story now (lol).

However, there is a reason why I wanted to research this, and I hope to write about that reason again soon ^^!

Source:Operation of Air Cooling Flaps 991.2

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