Buyers + Builders Guide
This guide is intended to help you find the right Porsche 718 Cayman or 718 Boxster and understand the build process. It is also intended to be a living document, where you — and others — can submit tips and tricks to finding and preparing a car. It should be noted, however, that this Buyers and Builders Guide is not a rulebook. It is highly recommended that all Club Spec owners review the Rules before starting their buy or build. If you have any questions, or would like to share your recommendations, contact us at ClubSpec@SCCA.com.
See bottom of the page for a complete parts list.
About the 718 Cayman/718 Boxster
The Cayman/Boxter for Club Spec is the fourth generation, known best by the chassis code 718. These cars were sold in the US from 2017 until 2025. The production run was all based on the same model, with several trims offered. The only Trim level allowed for Club Spec is the Base Model. There are a variety of trim levels, packages, and options, all of which can be studied in detail on the Porsche Cayman Wikipedia page.
Selecting a 718 Cayman/718 Boxster
If you are not already a 718 owner there are some things to look for when shopping. First, you want to find the right engine, which will point you toward a Base Model. Your next consideration will be whether you want the dual clutch PDK transmission or the 6-speed manual transmission. Although this is the Base model, the good news is it has a Turbo, and more importantly its still a Porsche. A final consideration should be looking for a car with the 3rd radiator, to help keep things cool on track.
Important buyers note
If you are looking at a PDK car, you should take care to make sure you are not getting a car with a Sport Chrono (QR5) package or the T trim. Besides having a slightly retro interior, there is some additional features which are not legal in Club Spec Cayman.
Performance Kit
With two exceptions, the Club Spec Cayman Performance Kit is required to participate in the class. The kit consists of wheels, tires, and suspension.
Suspension
The suspension kit for Club Spec Cayman was developed by Porsche for the 981 chassis cars as a sport suspension. Luckily the 981 and 718 chassis are extremely similar, allowing for a complete kit tuned for the chassis to be readily available.
The final piece of the suspension kit is a set of Camber plates, from Vorshlang. These allow for a better feel by giving the front end plenty of negative camber. This not only gives you better handling and feel, it’s also a must-have for increased tire life for both track and autocross. You want to buy the plates for OEM perches and an OEM strut, which you can find here.
The x73 kit is a pretty commonly available kit that was a Dealer installed option on the 981 Cayman/Boxters. You can find used kits on Rennlist.
Wheels and Tires
The front wheel size for the Club Spec Cayman is 18x9, with a minimum offset of +45 (offset number must be 35 or numerically larger, 36 and up) and a minimum weight of 17 pounds. The rear wheel size is 18x10, with a minimum offset of +35, and a minimum weight of 19 pounts. This size was chosen because of its popularity with Cayman owners and support in the aftermarket — there are lots of options to choose from. Of course, we recommend that you reach out to our partners at Tire Rack to help you find the one that is right for you. We expect they may tell you about the O.Z, Alleggerita. That’s the wheel we used to determine the minimum weight requirement.
Alignment
Alignment decisions will come down to how you want the car to feel, and how you plan to most use the car. If it’s primarily a daily driver, you may want to choose more conservatively than you might on a dedicated track and/or autocross car. That said, to get optimal performance, most will go for as much negative camber as possible in the front — generally around 2.5°. There are some tricks that most performance alignment shops will know that can help you get there — like lowering the caster to get a little more camber — but those are concepts best discussed with the shop you choose.
As for toe settings, toe in generally makes the car a little more stable, toe out in the front will give you a bit quicker turn in. Typically, zero toe is a good place to start until you get a feel for the car.
Once you have the suspension kit, wheels and tires installed, you have a Club Spec car and you’re ready to go!
Optional Modifications
Removal of Items
You may also — and you should — remove any loose items in the vehicle. This includes floor mats, but you can also remove the spare tire, jack and tools, and any other items that are intended to be removed such as an emergency kit.
Other Modifications
In addition to the above, you can also add basic, non-performance items to make the car feel like yours. This includes things like gauges, data systems or cameras, an alternate shift knob and upgrades to audio equipment. Especially for track use, it is highly recommended that you add a sturdy tow hook to each end of the car, just in case. If you plan to drive your car to and from events and need to take more gear than it will haul, you can also add a trailer hitch.
Durability Kit
If you plan to put your Club Spec Cayman on track, you may want to invest in some modifications to make it more track ready. None of these modifications will make it faster, but they will all help you and your car get more laps per session and more life out of key components.
Engine/Drivetrain
Especially if you plan to run longer track sessions, you may want to add an oil cooler. You can add any cooler you like, provided it serves no other purpose. You can also add the 3rd radiator option from Porsche, as long as it fits in the stock mounts.
Safety Upgrades
Those who are interested in putting their Club Spec Cayman on track should spend some time reviewing the SCCA Time Trials Safety Levels. The 718 Cayman and Boxster both meet Level 1 requirements with the factory safety equipment installed, however, Level 2 is highly recommended. Level 3 is also allowed.
Level 2 Safety
Level 2 includes a compliant roll bar, fixed back seats and racing harness(es). For Club Spec, you must add the roll bar to substitute seats and belts and, in doing so, you may also substitute the steering wheel or remove the airbag from the factory one.
Roll Bar
There are several reputable roll bar manufacturers out there. In choosing yours you’ll want to make sure that you buy from a brand you’re comfortable with. We recommend reaching out to a Cayman safety expert, a place where Competition Motorsports can help. Ensuring that your roll bar has the proper roll bar padding is also a must.
Racing Seats
Seats not only improve the fit and feel of your car, they’re also an important safety decision and there are lots of great options on the market. For Safety Level 2 compliance, they need to be one piece, fixed back seats with routing for belts through the seat. You may replace both seats or just the driver’s seat. The key to seat selection is fit, so it’s always a good idea to do some test fitting if you can. Good news — lots of common and popular seat models are generally found at an autocross or Track Night near you, and it’s a great way to meet people. We recommend starting your safety gear shopping with our partners at Summit Racing Equipment.
With awareness that some may wish to build their car in phases, you do have the option to keep the stock seat with a roll bar, but it is not recommended.
Harness
The harness you select will depend on several factors including whether you use a head and neck device such as a HANS, preferences in fastening mechanisms, and even color. Again, Summit Racing Equipment is a great place to learn about options and pick the right one for you.
Insurance
Don’t forget!! Whether you’re planning to track it or not, protect the car that you’ve put time, money and love into with the great insurance products from our partners at Hagerty. They can protect it on track, at home and everywhere in between.
Parts List
Download in Excel
| Part Number | Quantity | Description |
|---|---|---|
|
981-044-400-05 |
1 |
Porsche X73 suspension Kit for PDK car (Choose 1) |
|
981-044-400-01 |
1 |
Porsche x73 Sport Suspension kit for Manual Car (Choose 1) |
|
A1-6304-02 |
1 |
Vorshlang Camber plates for OEM Shock |
