The Porsche Cayman is as close as it gets to a perfect mid-engine sports car. Relatively speaking the “budget Porsche sports car” is the best bang for you buck when looking to live the “P-car” life but not break the bank. If you’re looking to turn a road-legal Porsche into a full-blown race car or simply have some fun on the street, possibly with some occasional track duty, you can do no wrong with picking up and modifying a Porsche Cayman or Boxster.

A stunning and one-of-a-kind blue 987 Cayman modified street car sitting at Regal Autosport in the UK, CSF’s premier dealer in Europe.

Being an official supplier partner to world-renown automotive culture website Speedhunters gives us access and the opportunity to work with some of the world’s unique vehicles. This collaboration is how a CSF 3-piece all-aluminum Porsche radiator system landed up on Ryan Stewart’s extreme 987 Cayman Street legal race car.

Ryan’s Cayman ready to get a full CSF 987 GT3 radiator system installed to keep his Porsche at an optimal temperature at all times… no matter what!

CSF radiators come meticulously packaged to make sure that transport around the world is no problem. Individually cut foam, poly-wrapped bag, and a Plexi-board protecting both sides of the core assure a perfect radiator ready to be installed.

Most people, even Porsche owners, don’t realize how the cooling system works on a water-cooled Porsche. Going all the way back to the 996/986 models and continuing through the most recent 991/981 generation; the Turbo, alongside the GT3, and some S models received three radiators (Left, Right, Center) while the regular Carrera and run-of-the-mill Boxster/Caymans only received the two side radiators. (There are exceptions when talking about newer special edition mid-engine models like the Spyder or GT4, but that’s not what we’re talking about now, so let’s get back to it!).

A lot of Cayman/Boxster owners install an optional auxiliary center radiator to help with overheating, especially on the track. Ryan took it a step further and installed the larger 997 GT3 center radiator for maximum cooling.

The Cayman/Boxster makes a great track car. However, with only two side radiators from the factory, serious track use or spirited driving tends to overheat the vehicle quickly. Dating back to the 986 models, Porsche quickly realized this and developed an optional auxiliary third center radiator retrofit upgrade. Ryan has taken his Cayman cooling capabilities one step further, and has “properly” installed, with correcting radiator brackets, hoses, and ducting (super important!), the larger GT3 center radiator into his vehicle (CSF #7053).

As you can see in the first picture, the center radiator is tilted downwards. This allows proper airflow to enter into the radiator and exit out of the GT3 style top bumper vent.

997/987 factory radiators can range from 5 to 11 years old. 996/986 radiators can be up to 18 years old if you still have the original units installed! That’s a long time, and many issues can cause the radiators to fail or diminish in performance over time. Bent over fins, clogged by debris, and internal corrosion; just some of the issues that Porsche side radiators face. Also, weaker style plastic tanks are prone to fail during track use, especially wheel-to-wheel racing where slight bumper contact or high vibration is possible. Tank problems were especially evident on 996/986 models.

Even with condensers installed in front of both side radiators, you can see how much dirt and debris has clogged up the Cayman’s radiators over the past ~8 years. Time to change them out for a set of stronger and more efficient brand new CSF all-aluminum radiators w/ B-Tube technology.

Watch Michael Essa (@michaelessa) talk about the CSF 996/986 radiators that he originally helped develop and test in his own 996 cup car.

When using just the two new upgraded CSF side radiators, vehicles will typically see temperature drops of ~10 degrees Celsius (~18 degrees Fahrenheit) when pushing the car hard + consistent and stable temperatures at optimal levels lap after lap, even in extreme ambient conditions or racing environments.

CSF worked with F1 level race team Tour-De-Force to collect detailed and accurate data on the performance benefits of CSF Porsche radiators.

So there you have it! A full run-down of how to properly COOL your 987/ 986 Cayman or Boxster. Make sure to check out the links above for help when installing your kit, and head on over to Speedhunters to read the in-depth article by Ryan himself on How to COOL a Cayman!

GT3 Center Radiator Install Instructions

Ryan (@7th.seal) has been kind enough to share his knowledge and instructions for how to properly install a GT3 center radiator into either your Boxster, Cayman, or even your non-S Carrera variant. From what we’ve researched, this might be the only place on the web to find this information. Check it out now!




Order parts as per parts list, also use CSF part numbers: 7047, 7048, 7053.

Points to note on installation:

The GT3 retaining frame will attach to Cayman tub via studs and holes present. No drilling required.

GT3 third radiator hoses mate directly to OEM Cayman radiator hoses, just remove bungs.

GT3 bleed vent ‘adaptor’ must be mated to a small length of radiator hose with a stopper in to create a bleed for the third radiator.

GT3 bleed vent ‘adaptor’ must be mated to a small length of radiator hose with a stopper in to create a bleed for the third radiator.

Cayman center vent ‘blank’ must be modified to fit GT3 front cowling

To do this, cut the frame from the Cayman blank and affix to bumper tabs. Next, trim the ‘ears’ from the GT3 item, this will allow it to sit flush with the Cayman bumper. A small length of weather stripping can then be pushed onto the GT3 front cowling to create a seal with the bumper.

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    I’m doing this conversion right now and to say I’m frustrated is an understatement. Can I get some help with a few points?

    First, can you provide more detail on how to trim the bottom of the GT3 center radiator bracket? Without trimming this bracket hangs about 2 inches below the stock Cayman bumper cover. Once the bracket is trimmed, it removes the lower radiator carbon mounting piece screw hole, how did you mount that bracket to hold in the radiator? Can you show more pictures?

    Second, to use the stock Cayman side radiator air ducts the center GT3 bracket has to be trimmed by a HUGE amount. After that, the center radiator end takes still impact the radiator duct. How did you address that? Can you post pictures with the side and center ducts mounted but without the bumper?

    Lastly – GT3 third radiator hoses mate directly to OEM Cayman radiator hoses, just remove bungs. What bungs are you speaking of? The hoses to connect the center to the side radiators are oriented specifically by two locating points on each radiator. If those don’t “click” in you will likely lose the hose under track conditions.

    Thank you!

    Have you read the Speedhunters article?

    CSF did not do the installation, but was merely a partner to Ryan Stewart from Regal Autosport in the UK – You may want to reach out to him via instagram: @7.nth – he will have the answers you’re looking for.

    I am very interested in installing this GT3 upgrade to my 2009 Carrera C2. I live in Dubai and track my car, where engine temps have limited my track time. Will these part numbers fit my 997.2? I have an upper vent from a body kit, so I would like to have it installed as functional if possible. Thanks for your great work and descriptions with photos, although I will use a shop to perform the install.
    Phil G.

    Is the list of part numbers correct for an ’06 – ’08 Cayman S (987.21 engine)? Or for which model is the list intended? The 7053 radiator listed is, according to CSF, the right choice for some models but not the ’06 – ’08 Cayman S. And so I am wondering whether the other hardware (retaining frame, duct, etc.) should be more along the lines of what Porsche in a model with the 987.21 engine and a Tiptronic.

    It will work with all OEM components. This is a true high performance OEM style replacement. You will not have to change any of the OEM parts to make these radiators work.