What Motor is in a Porsche Spyder GT? Inside the 4.0L Naturally Aspirated Flat-Six
The moment you press the start button and hear that 4.0-liter flat-six come alive behind your head, you understand why Porsche enthusiasts call this engine a masterpiece.
This is the heart of the Porsche 718 Spyder and Cayman GT4—a naturally aspirated flat-six that represents everything purists love about the brand. No turbos, no hybrid assist, just pure, high-revving mechanical magic.
TL;DR
The Porsche 718 Spyder GT and Cayman GT4 are powered by a specially developed 4.0-liter naturally aspirated flat-six engine (codenamed 9A2 Evo). This high-revving engine produces 414 horsepower and revs to 8,000 rpm, delivering power through a six-speed manual transmission to the rear wheels. It’s based on the same engine family as the 911 Carrera S turbo motor but features unique internals, piezo fuel injection, and adaptive cylinder control. The 718 Spyder RS uses an even more powerful version of this engine, shared with the 911 GT3, producing 493 horsepower and revving to 9,000 rpm.
Key Takeaways
- Engine Family: The 4.0-liter flat-six is codenamed the 9A2 Evo and is based on the turbocharged engine from the 911 Carrera S.
- Power Output: The standard Spyder/GT4 engine produces 414 horsepower and 309 lb-ft of torque, while the Spyder RS version produces 493 horsepower.
- High-Revving Character: The standard engine revs to 8,000 rpm, while the RS version pushes to an incredible 9,000 rpm.
- Transmission: Both the Spyder and Cayman GT4 come exclusively with a six-speed manual transmission with an “Auto Blip” rev-matching function.
- Unique Technologies: Features include piezo direct fuel injection, adaptive cylinder control (which can shut down one cylinder bank under light loads), and VarioCam variable valve timing.
The Evolution of Porsche’s Naturally Aspirated Flat-Six
Porsche’s decision to create this engine was a bold move. At a time when the industry was downsizing and turbocharging everything, Porsche’s GT division, led by Andreas Preuninger, decided to give enthusiasts exactly what they wanted.
The challenge? They couldn’t simply drop the 911 GT3’s engine into the 718—it was too expensive and designed specifically for a rear-engine layout. The solution was clever: create a new 4.0-liter naturally aspirated engine based on the 911 Carrera S’s turbo motor. Around 80 percent of the new engine’s components are unique to the GT4 and Spyder.
Porsche Flat-Six Engines: The 9A2 Evo Family
The engine in the 718 Spyder and Cayman GT4 represents a new engine family called the 9A2 Evo. It shares its 4.0-liter displacement, 81.5mm stroke, and 102mm bore with the GT3’s engine, but that’s where the similarities end.
What makes this engine special is its ability to be built alongside the standard Carrera engine, keeping costs manageable while delivering GT3-like performance.
Here are the key technical highlights of this masterpiece:
- Piezo Direct Fuel Injection: The engine uses piezo injectors—a first for a high-revving naturally aspirated Porsche engine. These injectors open by expanding crystals when voltage is applied, allowing for incredibly precise fuel atomization at up to 200 bar of pressure.
- Adaptive Cylinder Control: Under light loads, the engine can temporarily shut down one cylinder bank, effectively running as a three-cylinder. This reduces fuel consumption and CO2 emissions by approximately 11 grams per kilometer.
- VarioCam Technology: The electronic engine management adjusts the timing of the four camshafts across a 30-degree range, ensuring strong power delivery across the entire rev range.
- Forged Steel Crankshaft: The engine uses an extremely rigid forged-steel crankshaft with a 67mm diameter main bearing to handle the high revs.
From Standard Spyder to RS: The Power Upgrade
There are actually two versions of this 4.0-liter flat-six in the 718 lineup. The standard engine in the 718 Spyder and Cayman GT4 produces 414 horsepower, while the 718 Spyder RS gets a significantly more powerful version borrowed from the 911 GT3.
| Model | Engine | Horsepower | Redline | Transmission |
|---|---|---|---|---|
| 718 Spyder / Cayman GT4 | 4.0L Flat-Six NA | 414 hp | 8,000 rpm | 6-Speed Manual |
| 718 Spyder RS | 4.0L Flat-Six NA | 493 hp | 9,000 rpm | 7-Speed PDK |
The Spyder RS engine is a different beast entirely. It features individual throttle bodies for each cylinder, a central airbox fed by intakes behind the roll-over bars, and dry sump lubrication with seven suction stages to ensure proper oil supply during high-speed cornering.
Real-World Impact: What It Feels Like to Drive
Words can’t fully capture the experience of this engine. The 718 Spyder’s 4.0-liter flat-six is all about immediate responsiveness and linear power delivery. You feel the engine build power smoothly and progressively as the revs climb, with a soundtrack that’s pure Porsche—a rumbling howl that turns into a scream at high rpm.
Most of the noise actually comes from the intake, which sits right behind your head in the Spyder. The sports exhaust system, with its gasoline particulate filters and valve controller, helps deliver that iconic boxer sound while meeting strict emissions standards.
Acceleration is brisk: both the Spyder and GT4 hit 0-60 mph in 4.2 seconds and reach top speeds of 187 and 188 mph respectively. The six-speed manual transmission features an “Auto Blip” function that automatically rev-matches on downshifts, though you can turn it off if you prefer to do it yourself.
Chart: The 4.0L Flat-Six Power Comparison
4.0L Flat-Six Power Output by Model
FAQ
What engine is in the Porsche 718 Spyder?
The Porsche 718 Spyder is powered by a 4.0-liter naturally aspirated flat-six engine producing 414 horsepower and 309 lb-ft of torque.
Is the 718 Spyder engine the same as the 911 GT3?
No, the standard Spyder engine is based on the 911 Carrera S engine family, not the GT3’s engine. However, the 718 Spyder RS does use the 911 GT3’s engine.
Does the 718 Spyder come with a manual transmission?
Yes, the 718 Spyder comes exclusively with a six-speed manual transmission with an “Auto Blip” rev-matching function.
What makes the Spyder RS engine different?
The Spyder RS uses the 911 GT3’s engine, producing 493 horsepower and revving to 9,000 rpm. It also features individual throttle bodies for each cylinder.
How reliable is the 4.0-liter flat-six engine?
Porsche’s naturally aspirated flat-six engines are known for their reliability and durability, with many components derived from motorsport technology.
What is adaptive cylinder control?
It’s a feature that temporarily shuts down one cylinder bank under light loads, allowing the engine to run as a three-cylinder to reduce fuel consumption and emissions.
What’s your favorite naturally aspirated Porsche engine? Share your thoughts in the comments.
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