The air-cooled Porsche restomod scene has turned into an arms race, and Oxfordshire’s Theon Design keeps entering it with a different strategy. Instead of chasing the biggest horsepower number, the British shop fixates on weight, balance, and a level of personalization that certainly rivals their counterparts on Singer.
Its newest commission is a 964-generation 911 rebuilt almost entirely in carbon fiber. This old air-cooled coupe makes less power than a current 911 GT3, yet still walks away from it when it comes to power-to-weight.
Carbon Everywhere But the Doors
That carbon body drops the wet weight to a featherweight 2,526 pounds (1,146 kg), a few hundred pounds under the modern 911.
Theon could have shaved off even more by swapping the doors for carbon, but it deliberately kept the original steel units. The logic is pure enthusiast: a classic 911 door has a specific feel and sound when it shuts, and the company refused to trade that away to save a couple of kilos.
An Air-Cooled Flat-Six Worth 421 HP
Hung out behind the rear axle is a naturally aspirated 4.0-liter air-cooled flat-six making 421 horsepower and 324 lb-ft of torque, sent to the rear wheels through a six-speed manual. No turbos, no hybrid hardware, no paddles. It’s the exact recipe purists keep begging modern Porsche to revisit.
A MoTeC ECU runs everything, with a drive-by-wire throttle feeding six carbon intake trumpets and a set of drive modes. Most of them are civil, and expected, but then there’s the oddly spelled “Raucus” mode, which unleashes full power, raises the spoiler, and turns the exhaust into a barrage of pops and bangs.
Tuned to a Single Owner
The car was developed alongside its owner, who set the steering weight, throttle response, and suspension behavior to personal taste before the build was signed off. None of this was “off the shelf.”
Underpinning it all is TracTive semi-active suspension with five selectable settings, plus a front-axle lift system so the low-slung coupe can clear a driveway without scraping its chin. It’s daily-driver friendly, in theory at least.
Analog Cabin, Sneaky Tech
Inside, the carbon panels are wrapped in hand-trimmed Liquorice leather with Lizard Green stitching and paired with Recaro RS bucket seats. There are period-correct machined aluminum details throughout, and the gauges have been color-matched to the exterior.
The carbon center console packs a wireless charging pad and a phone mount, while a vintage Becker Mexico head unit secretly powers a Hertz amp and six Focal speakers. The analog illusion stays intact, but thre’s also plenty of modern tech to boot.
Spec Sheet
Model: Theon Design Porsche 911 (964) Commission
Engine: Naturally aspirated 4.0L air-cooled flat-six
Power: 421 HP and 324 lb-ft of torque
Transmission: 6-speed manual
Drivetrain: Rear-wheel drive
Weight: 2,526 lbs (1,146 kg)
Body: Full carbon fiber (steel doors retained)
Suspension: TracTive semi-active, 5 settings
Wheels: 17-inch, Anthracite and Black
Production: 6 commissions worldwide for 2026
Pricing & Availability
Theon will hand over just six of these commissions worldwide in 2026, with each build swallowing roughly 6,000 hours of labor. Pricing starts at £430,000 (around $577,000), and that figure pointedly excludes the donor 964, shipping, and taxes. A clean donor car runs anywhere from $90,000 to $150,000, so budget accordingly.
Recap
Theon Design Porsche 911 (964) Restomod
Theon Design rebuilds the air-cooled 964 with a full carbon body and a 421-HP flat-six, landing a better power-to-weight ratio than a current GT3.
