Project 987.2 Cayman S: Getting More Out of the Engine to Chase the GT4 Part 2

Compared to the stock exhaust manifold, the Fabspeed headers have longer, uncrimped primaries with a smoother merged collector. Look how crimped the runner for the first cylinder is. Look how different in length the primaries are. The Headers should be good for a lot more power.  The Fabspeed headers are 10 lbs lighter than stock.

The Fabspeed headers bolt in place easily.  They have a thick CNC machined stainless flange for leak free sealing to the head.

The Fabspeed headers are in place.  Now it’s time to install the exhaust.

You can see the difference between the stock exhaust and the Fabspeed Valvetronic exhaust.

The Valvetronic exhaust is 13 lbs lighter than stock.  When combined with the headers the Fabspeed system loses 26 lbs from stock! The Valvetronic system uses the vacuum actuators you can see here to open and close a valve that can divert the exhaust gasses through the mufflers or run straight out the back of the car with minimal backpressure. The Valvetronic system is compatible with the OEM Porsche PSE sports exhaust system with the center console switch or you could use the Fabspeed Valve Controller kit and use their remote control to operate the valve.

The Fabspeed exhaust bolts back in in the reverse order as stock.


  1. I’m sure there’s a reason, I’m just curious why the vacuum actuators weren’t placed closer to the muffler bypass T-section.

    1. That is about the only place they could be to divert the flow to either though the mufflers or the bypass.

      1. The length of pipe leading up to the bypass valve probably works as a Helmholtz resonator to additionally reduce drone. Or not.

        1. This is my thought as well, I wish I had time to experiment with Helmholtz resonators on my own cars, but seeing little stubs like this absolutely makes me think that’s at least part of the reason for their placement.
          I’d imagine with the length being so short (12-18″?), it might help cut out rasp more than drone, but it should provide some effect without hurting exhaust flow (and power) too much at lower loads….

          1. The thing is the bypass is open on both ends so it’s not a Helmholtz resonator. Having two exhaust paths of different lengths does change the frequency and possibly cancels out some frequencies though and the exhaust isnt as loud as you would think when its open

  2. Curious question, so, when you are performing the modifications to your Cayman, is this a road legal car? Or is this track use only? I would like to think it’s a track only car not to be used on the road?Iif not, the removal of the catalytic converter would be a big EPA issue?

    1. It is a track car. It says so in the articles about this project and twice in the first paragraph in this article.

      1. But you’ll be comparing it to the GT4 power-wise…which still has full emissions?

        A bit of apples to oranges comparison, no?

        1. This is a track car, not a street car. Plus a GT4 is tens of thousands of dollars more. A GT4 Clubsport is over a hundred thirty thousand more and we think we can come very close to this, perhaps exceed it in some aspects.

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