Project Porsche 987.2 Cayman S: Getting the Suspension Together! Part 2

We fabricated this switch panel to go where the ashtray used to be.  The bottom switch is for the KW HLS pump. The top switch is for the solenoid valve.  You can work it by turning it on when the car is at its low ride height and then activating the HLS pump will only raise and lower the back of the car for the DRS system.

We also installed our Rennline strut tower brace.  It is important because we are running really high spring rates and we don’t want the chassis to flex even the stiff Porsche chassis.

The Rennline strut tower brace bolts to the strut tower in two places.  It would be pretty hard to make it fit three due to the odd shape of the tower as shown here.

We had to trim the stock plastic covers for the battery area to get the strut tower brace to fit under it.

Once we did though it was a nice clean installation for the brace and the HLS system.

At this time we installed the rear Rennline brace with the optional tie-down hooks.  These should be a good thing if we ever have to trailer the car to an event!

10 comments

  1. Great as usual, curious to see how this does on the track. I run the atx-20 on my wrx. At three pounds and change it’s great. My car starts better with this over the factory battery, however it sits on a battery tender. While I haven’t had to use the restart feature, it’s another reason to like this battery.

    Have you thought about this?

    https://www.autoquestcars.com/custom-09

    1. I would be careful and run a battery tender that is for lithum batteries only! A well-known friend of ours blew up his car and almost burned down his shop because he used the wrong trickle charger!

      My opinion of this kit is that the upper links are way too short and you will have too much camber gain for rear-driven wheels. The short links can also contribute to jacking and lots of roll center and instant center migration. The short links will also cause side scrub which can contribute to instability on split mu surfaces and under certain load conditions. Lastly, the anti-squat percentage is really high and that can contribute to a loss of traction under corner exit as well as wheel hop. The Cayman/Boxter chassis has wheel hop as a known issue and they exhibit a high degree of anti.

      I may be working with a well-known Porsche suspension parts company next year to develop my own solution to these issues on the 987 chassis which if it comes to fruition will be much better than this! At least in my own opinion.

      1. Oh yeah, I use a lipo specific one. Not making that mistake. Lipo fires are for Richard Hammond anyways.

        Competition is a wonderful thing, love to see what is born!

  2. I enjoyed the 3 pages on the alignment and all of the other 987.2 Cayman content. Can you write more about setting the anti squat / dive front and rear? Also, about how the team measured the bump steer? All of the specs? Have you run the car on track yet? How did it feel, any adjustments?

    I have a 987.2 will all of the Tarett parts that your car has and have not been able to find a shop around Atlanta that will got to this level of detail.

    Thank you

    1. We are waiting for softer front springs right now. I want to go down to 10 kg and KW is backordered. The balance of the car is ok but there is a minor pitch issue I think is frequency related so I want to go softer spring wise in the front and up in the front bar. As far as bump steer, Porsche is pretty well designed and there isn’t much, but if you mess with the roll center you need to move the tie rods by close to the same about or you will get bumpsteer. Basically, if you want to measure it you take off the springs and move the car up and down and measure toe every inch and plot it. However, we did this and the toe curve on these cars is pretty good. I would talk to my local PCA or POC racers and they probably know a prep shop that can properly align and corner balance your car. The specs we gave in the article were pretty aggressive like what cup cars run so they would kill your tire on the street if your car is a daily. To make it simple to reduce anti we shimmed the front trailing arm pivot down, The 987 has a lot in the rear.

  3. Great looking build! I have a 987.2 I am setting up similarly for HPDE days.

    Any chance you can provide some insight into your recommended ride height and how you came up with it?

    I’ve got Ohlins on mine, and I have lowered it too far. My LCAs are pointed upward on the outside and thus my roll center is super low and my camber curve isn’t great. I’m trying to figure out how high to raise it but I’m a little lost.

    Thanks!

    1. We lowered the outer LCA pivot by putting a spacer on the spherical bearing. We also lowered the tie rod to reduce bump steer.

      1. Okay cool. I have that ability with my front LCAs but I am still stock in the rear. Did you aim to have your LCAs at a certain angle at ride height or at full compression?

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