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

Unlike Japanese cars that typically use bolted flanges, Porsches use slip joints and clamps like a lot of American cars just executed a little better.  We removed them so we could take the exhaust apart.  There is one bolted flange from the exhaust manifolds to the exhaust.

This tubular bracket holds the rubber hangers for the rear muffler section of the exhaust.  We unbolted the hangers from it and the stock exhaust was now ready to drop from the car.

The heavy stock exhaust out of the car. The huge mufflers are needed due to the short exhaust tract.

Next the exhaust manifolds are removed from the heads.  On a Porsche this is pretty easy and it’s easy to access the bolts.

The manifolds slip out easily since the chassis braces are out of the way.

We will be replacing the manifolds with Fabspeeds long tube race headers. The headers are constructed of polished 304 stainless with beautiful tig welds. The headers have longer primaries than most of the headers for the 987 on the market.  The primaries are equal length and feed into a high velocity true merged collector that is investment cast from stainless steel.  Merge collectors give a good blend of torque and top-end power.


  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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