Boxster / Cayman Engine Options
Choosing Your Engine: K20 vs. K24
When planning a K-Series swap for your Boxster or Cayman, the first step is choosing the right displacement. While both are world-class powerplants, they deliver power very differently.
The K20 (2.0L)
The K20 is a "high-strung" engine designed for those who love high-RPM excitement.
- Redline: 8,500 – 9,500 RPM.
- Characteristics: Extremely "rev-happy" with impressive peak horsepower at the top of the tachometer.
- Trade-off: Produces significantly less torque than the K24, which can make it feel less "punchy" in a mid-engine Porsche chassis.
The K24 (2.4L) – Our Recommendation
For the majority of Porsche swaps, we recommend the K24.
- Redline: 8,000 – 8,500 RPM.
- Characteristics: It matches the K20’s peak horsepower but achieves it earlier in the rev range. Crucially, it provides significantly more torque across the entire powerband.
- The Advantage: This extra displacement makes the car feel much more responsive in daily driving and corner exits.
K24 Variants: K24A vs. K24Z
If you decide on a K24, you must choose between the "A" series (traditional 4-port exhaust) and the "Z" series (integrated single-port exhaust).
| Feature | K24A (2004–2008) | K24Z (2009–2015) |
|---|---|---|
| Exhaust Design | 4 individual exhaust ports. | Single "integrated" exhaust port. |
| Availability | Harder to find with low mileage. | Abundant; found in 2012–15 Civic Si (K24Z7). |
| Aftermarket | Massive support for cams/headers. | Growing support; excellent for turbocharging. |
Which one is right for your build?
Your choice should depend on your ultimate power goals and how you plan to use the car:
1. Naturally Aspirated (250–300 HP)
Best Choice: K24A
If you want a nimble, responsive, N/A setup, the K24A is the gold standard. The traditional 4-port head allows for a wide variety of aftermarket headers and high-performance camshafts, making it easier to hit your naturally aspirated horsepower targets.
2. Forced Induction (400+ HP Turbo)
Best Choice: K24Z
The Boxster/Cayman engine bay is notoriously tight. The single exhaust port of the K24Z makes turbo manifold packaging much simpler. Because you aren't fighting for space with a bulky 4-to-1 manifold, fitting a turbocharger into the limited mid-engine footprint becomes a much more manageable task.