- Porsche Cayman GT4, credits to Porsche

Porsche is holding back its Cayman for the 911, but not in the way you think

Respect the family hierarchy, little guy.

5d ago

17.5K

It had long been speculated that Cayman isn't nearly as good as it could be because Porsche needs to save face for the 911.

On the face of it, this conspiracy theory isn't without the backing in fundamental physics. However, it is not quite as simple as it looks. Let me explain.

50:50 Weight Distribution

As many car manufacturers like to boast about the 50:50 weight distribution of their vehicles, the fundamental way a car behaves near its limits is dictated by its weight bias.

Mazda MX-5 "Balance" Ad

Mazda MX-5 "Balance" Ad

What is 50:50 weight distribution, exactly? Well, it means that the front and rear axles bear the same amount of weight, thereby making it possible for the Miata in the picture above balanced.

Below is Motortrend's Dimension data for 2017 Cayman S and 2020 992 Carrera S:

End of story, right? Cayman's 44:56 weight distribution is clearly superior to the 36:64 of the 911's. Well, almost, but not quite.

Your 50:50 is not the same as my 50:50

Audi RS3, credits to Audi USA

Audi RS3, credits to Audi USA

Let's take a little detour out of Porsche and talk about Audi. For ages, Audi's performance RS cars have been criticized for their tendency to understeer. Let's take the RS3 for example. The commonly blamed factor is its 58:42 weight distribution, which means that it's overwhelmingly nose-heavy. But what if I load up its trunk with, say, manure?

Theoretically this could yield a 50:50 weight distribution, and that it would be the easiest fix to a fundamentally handicapped vehicle dynamic characteristic. So why hasn't this been implemented? Well, it's because the weight is hanging way off to the front of the front axle.

My beautiful 1-minute creation

My beautiful 1-minute creation

By doing so, it will increase the rotational inertia, making the vehicle less prone to turn. In a way, Porsche's 911 is like the Audi RS3, but with its engine hanging over the back. You can't simply load up the 911's frunk to make it handle better because you can "achieve 50:50 weight distribution".

To help you visualize this, here's a high school physics lesson that you are probably familiar with:

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As you can see, as the instructor pulls the masses in, his angular velocity (the rate at which he spins) increases, which is analogous to how a car is more eager to turn with its mass closer to the center of the vehicle.

Unlike the 911, Cayman has its engine in front of the rear axle, reducing its rotational inertia and thereby making it more eager to turn. Even Porsche's 911 RSR racer, albeit being a 911, has its engine in front of the rear axle, just like the Cayman.

911 RSR, credits to Porsche

911 RSR, credits to Porsche

And the racing drivers in Japan, including Keiichi Tsuchiya himself, took a Cayman and 911 to the Gunsai Touge for a face-off. They also mentioned how Cayman felt more nimble in the winding mountain roads. [P.S. English caption available]

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So, is Porsche deliberately holding back the Cayman for the 911? Very likely. But we should still give Porsche much credit for persevering for the past half a decade to make such an unconventional engine layout work, along with the unique driving experience that results from it.

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Comments (10)

  • yea... except that cars do not rotate around their center mass in a turn. Cars effectively turn around their rear wheels. Unless they have rear wheel steering, but that's a different story, and doesn't change this effect at any speeds higher than parking lot maneuvering.

    As such, front heavy is bad for agility, but rear heavy is not. Which is why 1911s used to overturn aggressively - aka spin out of control and crash into a tree - hardly lacking turning ability, wouldn't you say?

    50/50 distribution is still good, all things considered, but depending on how other things are tuned, 44:56 is not necessarily superior to 36:64. For example, wider/stance'd rear tires can adjust for the imbalance of grip limit, and you get a very agile and yet controllable car.

      4 days ago
    • My model is highly simplified and may not account for all cases. However, if cars indeed rotate with respect to the rear wheels, you'd expect the rears wheels to barely move because everything is rotating around them. Also, it would be the...

      Read more
        4 days ago
    • "you'd expect the rears wheels to barely move" which is exactly what happens.

      "it would be the front wheels that are very prone to lose control" which is also what happens, but that is dependent on a lot - and I mean a LOT - of other things that...

      Read more
        4 days ago
  • Great write up and whilst a fair number of people have experienced it they don know the physics behind it.

    The cayman is indeed brilliant and yes they could make it better still but this is that hierarchy within Porsche where the 911 is still at the top of their sports car tree so the only way to keep hierarch is to make the cayman slower as even post high can’t defy physics. The cayman will always handle better and if Porsche ever stopped making a 911, guess what you think the cayman could be with all Porsche’s know how.

      5 days ago
  • A couple episodes ago on Matt Farah's the Smoking Tire Podcast, it may have been the one with Demuro on, but towards the beginning, he talks about his time in the new Cayman GT4 and how the transmission, along with this topic, is another factor holding it back from the 911 performance wise. Says the first 2 gears are far too long, and with a quick $20k modification (ha!) this can be solved. He'll explain it much better than I.

      4 days ago
  • Such a great car that usually gets the comment of ‘you bought the wrong Porsche’ whenever you want to upset a Cayman owner.

      4 days ago
  • I just think of the Cayman as a hardtop Boxster.

      4 days ago
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