Project Cayman T: Part 1 – Intro and Must-Do Mods

For those auto-crossing and doing track days, removing the tire goop, tools, air compressor, and plastic cover shaves 10lbs. I forgot to take out the owners manual, but I would ballpark that at 5lbs.

Speaking of shaving weight, I started off the year logging a few miles on the bicycle and I took off about 6lbs from ‘working-too-much and not-exercising’ peak weight. Then I got a puppy, so I have barely touched the bike in After Puppy time. I really need to rack up some miles like I did back in the day. I would say I am still about 6lbs above where I was when I was in peak shape.

I fit inside the frunk with room to spare, though I am facing away from the emergency interior opening handle. So, I would die if the hood were closed. Please do not transport live people or animals in the frunk.

The T comes with these dark colored wheels stock. I would not recommend going with a silver or other light colored wheel on a performance car. I had about 250 miles on the car in this picture and the wheels are already turning a nice shade of brake dust. It is hard to make it out, but the rear wheels have roughly double the level of brake dust hue.

In the name of reducing rear brake pad wear, I had to figure out a way to deactivate the PTV system. It seems if one were to disable PSM, which does disable the auto-rev matching feature, PTV would still stay on. A quick search in the forums and I was able to find the PTV system located under PSM in the Launch X431. I shutdown the PTV. The purpose of PTV was to improve turn-in. I will do that through suspension adjustments which are also required to keep from destroying the tires on track. The stock components can only get about -1.5deg of camber. I am targeting -3.0 which requires new suspension bits. Something interesting about the ‘outdated’ entertainment center of the 718 Cayman, you can watch DVDs on it while you are parked.

Here is a random bit of neat engineering: the gas cap holder. The fancy origami cup holders that fold out from the dash are worthless though. Note the sticker on the gas door calling for 93 octane. We only get 91 octane in Cali, so… yeah.

The picture of the grill set from the Radiator Grill Store gave away this future mod which are GT4 side scoops. I got them from with the GT4 filled-in and everything painted in black-trim color. They came excellently packaged to avoid damage.


    1. I auto-x’d a C6 when it first came out way back when. I didn’t care for it; it felt bigger than it was whereas the Cayman feels smaller.

      1. I hear you. I cycled through an AP2 S2000, C6 Z06, F80 M3, and now TTRS daily and 991.1 GT3 track car. between these cars and rentals and driving friends’ cars, realized I valued a smaller lighter car and mid/ rear engine feel over other factors. There’s always someone richer/ smarter/ faster, go the route that makes you happy.

    2. Except Khiem has a car he can drive to and from the track comfortably and also drive on a daily basis. A Cayman is far more comfortable than a C6 on a day to day basis. More interior and trunk space as well. Plus he doesn’t have to put up with a god awful early 2000s GM interior.

      More money, but you get what you pay for.

  1. I have solid trans mounts in my base 718. I think I bought the 981 models from tarett engineering. With the standard mounts a floor jack under the back end of the trans could move it 1.75 inches before the car moved. That was with 20k miles. Didn’t notice much change in nvh. Improved shifting a lot.

    1. Good to know on the compatibility! I was hoping Porsche would carry over parts as OEMs do to save money. I still need to figure out how to disable any potential error codes because of the active mounts. I hopefully can code out the active mounts as they are an optional feature.

    1. It’s a digital tach. But at least one of the display options is round like an analog tach. Other options include a bar…. graph, I guess you could call it. Which I did not particularly care for on the S2000.

  2. Thank you for the explanations of how the switched water pump works to reduce temp in sport mode! I do have the same idea of leaving it open all the time for cooler operations. I like the idea of plugging the control vacuum line. Do you know where that pump is? I have a 23′ CGTS 4.0. It has the same enhanced cooling feature, and I’d think it has the similar cooling components. Thanks!

    1. I don’t know where it is on the 4.0L 6-cyl, but on the 4-cyl turbo, it’s on the side of the engine next to the passenger compartment bulkhead. I’ve found pictures of where the vacuum line goes and it’s not easy to get to.

      For now, I’m content with just running the car in Sport + mode all of the time. I need to ask someone to see if the water pump still stays closed for faster warm-up from a cold-start even in Sport + mode. I imagine it would in order to reduce emissions. In Sport +, even during track use, I only saw the coolant temp get up to 87C max. I’ll see it fluctuate between 82-86C during everyday driving.

      EPDM rubber is very commonly used in cars for gaskets, o-rings, and coolant tubes. Anything related to the coolant system, EPDM is typical. It commonly comes in two grades, cheaper that is good for 120C and more expensive that is good for 150C. Having worked for a long time in the auto industry and also observing the frequency of water pump failures on modern Porsches, I have it a very high likelyhood the cheaper rubber is used in the water pump. I mean, there’s even a plastic impeller instead of metal. OEMs are looking to save a dollar anywhere they can.

      In Normal mode, it seems the coolant runs between 100-105C. Which is a lot closer to that 120C limit. So my hypothesis is running in Normal degrades the seals and gaskets in the water pump much faster. Plus the engine runs much warmer oil. So after a drive and doing a shutdown, everything is just going to be hotter. But running in Sport + with the coolant only around 85C and oil around 90-95C, the seals should last much longer. Fingers crossed.

  3. Thanks again for sharing your knowledge! I’d think the thermostat should take care of the faster warming up mostly, as it opens up typically at 180-195F (not sure about Porsche cars)? The open water pump will circulate the coolant continuously, but might not affect the oil warm-up much…at least, that’s my theory :).
    Aside from the vacuum controlled water pump you mentioned, there looks to be a vacuum control valve for the coolant going into the engine oil cooler. I don’t know how to add picture here, but if you google ‘718 BOXSTER ENGINE OIL COOLER INLET LINE OEM 98130707500’, you will likely find used parts that show the picture. It looks to be controlling the amount of coolant, or maybe just on/off, going into the engine oil/water exchanger (located on top of the engine, driver side, by the oil filter in the 4.0L)
    I’ll make a spring project to play with vacuum lines and see what happens 🙂

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