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Discussion Starter #1
I'm a happy new owner of a 2006 Cayman S....especially happy since I spent three years of my life on the development of the car while I worked at Porsche. 10 years later I finally own one and find that the ride height leaves a lot to be desired. Of course there were good reasons why the car was designed with such a high suspension setup (snow chain clearance, etc) but since I don't plan to go skiing with it in Colorado I'd much rather drop it down.

Now, I realise this question has been asked 1000 times and I've been been trolling the forums for days without finding a "good" answer. Who makes a spring kit that works well with the stock struts and shocks?

So far I found:

Eibach and H&R: Lower by 30mm (1.2") and make a harsh, bouncy ride. Also difficult over speed bumps and angled driveways

Cayman R springs: Lower by 20mm (3/4") and hardly stiffer ride from stock

The R springs seem to be the best compromise to get a decent look and everyday usability. However answer that I could not find was whether R springs would fit on the stock 2006 shocks and struts? Would anybody here know?

PS: The internal project name for the Cayman was always C7 until the final name was chosen in 2003
 

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Welcome to the forum - and to the Cayman, again.

From working on the car I am sure you know that it is the geometry change that creates the harshness, not so much the spring rate. Lowering the car removes the angle, and therefore the force couple, on both the control arm (roll) and trailing arm (dive, squat). Lowering it too much also removes all dynamic camber gain and worsens handling. In addition, it lowers the roll center, increasing the roll couple, which actually makes the car roll more, not less, for a given spring rate - encouraging folks to use even stiffer springs or anti-roll bars.

The Cayman is delivered with about 7 degrees of angle in the control arm (pointed down and out). This decreases by about 1 degree for every 0.2 inch the car is lowered, so lowering the car 1.4 inches removes all angle from the control arm and most of the angle from the trailing arm. The control arm angle reduction increases the roll couple (bad) and kills camber gain (bad), and the loss of trailing arm angle reduces the force couple that compresses the spring (overly limits squat), making the car harsh and prone to a flat slide under throttle (really bad). Think about a motorcycle swing arm and how the force vector is transmitted to the spring/damper.

These issues can only really be corrected with new uprights or altering the pickup points in some other way.

So, all of that said, you are probably better off with the R springs or a set of coil overs that allow you to control the ride height (and limit the drop to 0.8 inch or so).

Cheers,
 

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Discussion Starter #3
Thanks for the welcome and the very thorough response. You are absolutely right in pointing out that suspensions are complex beasts. That is one of the reasons why the stock Cayman R setup is so appealing to me....I know the suspension engineers in Weissach have done their homework and it'll work nicely within the suspension geometry. From what I was able to gather on the internet the spring rate on the R is only about 10% stiffer than on my stock car...that is well within reason to not have to replace the stock dampers. I'll figure out whether there is enough damper travel left on the stock car to support the additional upward travel before it hits the bump stops. If so, then the Cayman R spring rate and amount of lowering would be a perfect compromise between everyday driving and good aesthetics. And at about $450 dollars for a set of springs it would be a very economic way too.

If the R springs don't fit the 2006 shocks, I would even be interested in getting custom springs coiled. There are minimum order quantities involved, but with a group of 5-10 people it would make sense to get dedicated R-spec springs made for the first generation Cayman. If anybody else is interested hit me up via PM
 
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