This is a Birkin S3 that’s powered by a Suzuki GSX1300R Hayabusa inline-four, an engine that produces 175 bhp at a screaming 9,800 rpm. Power is sent back through a 6-speed manual gearbox, to a limited slip diff rear end.
Given that the average Birkin S3 has a curb weight of around 1,200 lbs (544 kgs), this car has something like 322 bhp per metric ton, putting it into a league only usually occupied by supercars, hypercars, and dedicated race cars.
Fast Facts: A Hayabusa-Powered Birkin S3
- This Birkin S3 is an unusually extreme Lotus Seven-style build, using a Suzuki GSX1300R Hayabusa 1,298 cc inline-four rated at 175 bhp at 9,800 rpm. With an average Birkin curb weight around 544 kgs (1,200 lbs), the car works out at roughly 322 bhp per metric ton, giving it performance well into supercar territory.
- Birkin Cars was founded in South Africa in 1982 by John Watson, who began building Seven-style cars after political upheaval forced him to leave Rhodesia and abandon his own Lotus Seven project. Unable to import a Caterham affordably, he built his own version, which quickly grew from a personal hobby into a manufacturing business as other people requested kits.
- Early Birkin success was helped by a contract with a South African Lotus dealer, leading to a public debut at the 1983 South African Grand Prix at Kyalami. The company expanded through the 1980s, building lightweight aluminum-bodied S3 models in both turnkey and kit form, later adding wider, longer, and more track-focused variants.
- The Birkin S3 shown here was bought as a kit in 2004 and assembled by Hamlin Fabrication in California, with the build completed in 2008. It has a 6-speed sequential gearbox, adjustable coilovers, four-wheel disc brakes, and a live rear axle later upgraded with a Speedway Engineering quick-change limited-slip setup installed in 2021.
History Speedrun: Birkin Cars
The Lotus Seven is one of the most replicated car designs in automotive history, and among the best-regarded reproductions are those built by Birkin Cars, a small South African manufacturer that has been turning out lightweight, aluminum-bodied Sevens from its base near Durban since the early 1980s.
Given that the average Birkin S3 has a curb weight of around 1,200 lbs (544 kgs), this car has around 322 bhp per metric ton, putting it into a league only usually occupied by supercars.
Birkin was founded in 1982 by John Watson, a Welsh-born engineer who grew up in Rhodesia (now Zimbabwe) and had been besotted with the Lotus Seven since childhood. Watson’s middle name was Birkin, given to him by his father in honor of a distant relative – Sir Henry “Tim” Birkin, the legendary British racing driver who was one of the original Bentley Boys in the late 1920s.
Tim Birkin was instrumental in the development of the supercharged 4½ liter “Blower” Bentley and won the 24 Hours of Le Mans in 1929. He died tragically in 1933 at the age of 36 after a minor burn sustained during the Tripoli Grand Prix turned septic.
Watson’s path into the world of car manufacturing was born out of frustration more than any other single factor. In 1978, political upheaval in Rhodesia forced him to relocate to South Africa, but emigration laws limited him to only being allowed to import a single vehicle, this meant his Lotus Seven project car had to be left behind.
Attempts to import a Caterham Seven were crushed by prohibitive South African import duties of 110%, and a direct approach to Caterham’s Graham Nearn about building them under license in South Africa was politely declined. Watson decided to build his own, and it seems likely that Caterham would come to regret their refusal, as Watson’s high-quality Sevens soon became a key sales competitor for them.
Working from a tiny workshop in Pinetown just inland from Durban, Watson constructed his first car armed with every Lotus Seven reference book he could find and an engineering background from his studies at the Technicon in Salisbury.
There was no grand business plan, as Watson later recalled in an interview with Birkin Australia, the project was simply a hobby that spiraled – one car became two, then three, then four, as friends and fellow enthusiasts lined up to commission their own.
This Birkin S3 is powered by a Suzuki GSX1300R Hayabusa-sourced 1,298cc inline-four mated to a 6-speed sequential transmission. This engine is good for 175 bhp at 9,800 rpm and 104 lb ft of torque at 7,000 rpm.
The Birkin-Lotus Link
The local South African Lotus dealer caught wind of the project, inspected the car, and offered Watson a manufacturing contract. It was an incredible coup for Watson, and it would help set his fledgling company onto the path of becoming known internationally.
The result of this Lotus dealership contract was a high-profile public debut at the 1983 South African Grand Prix at Kyalami, an event attended by Hazel Chapman, widow of Lotus founder Colin Chapman, and Lotus Formula One drivers Nigel Mansell and Elio de Angelis.
Interestingly, the launch coincided with the 50th anniversary of Tim Birkin’s death, a meaningful coincidence that wasn’t missed by Watson. An initial batch of 12 limited-edition cars, all finished in Team Lotus JPS black-and-gold livery, was commissioned by the Lotus dealer and became an instant sales success. The first completed S3 Roadsters were delivered directly to Lotus dealerships, and offered for sale right next to the brand new Lotus cars then in production.
The 1980s proved to be a boom period for Birkin, strong demand from the United States and Japan turned the cottage operation into a proper production concern, though the company remained based in the Durban area in KwaZulu-Natal. The Birkin S3 platform, the basis of the entire Birkin model range, was offered as either a fully assembled turn-key car or a DIY kit car.
Birkin Specifications
Its lightweight tubular steel chassis, aluminum body panels, and performance-bred simplicity aligned perfectly with the original Lotus ethos of performance through light weight. Engine options over the years have included Ford Zetec and Duratec units, the Toyota 4A-GE, and Mazda powerplants, among many others fitted by homebuilders around the world. Some have even been fitted with modern superbike engines.
The cockpit is fitted with Birkin-branded bolstered bucket seats, an OMP quick-release steering wheel, an adjustable pedal set, and a roll bar with shoulder belts. Instrumentation includes a SPA Design 12,000 rpm tachometer, a VDO 120 mph speedometer, and additional auxiliary gauges.
Over the decades, the Birkin range expanded to include street and some more track-focused variants – the SS3 (street), the wider and longer SS3XS “Extra Space” model – roughly 100mm wider and 75mm longer in the cockpit, and the Clubman-series CS3 and CS3XS, which add FIA-compliant roll cages and aero screens for dedicated circuit use.
The company also developed an independent rear suspension setup to replace the earlier live axle configuration to further improve handling. The cars still remain faithful to the original Lotus Super Seven Series 3 template, with empty weights starting at around 550 to 570 kgs depending on specification, that’s 1,212 – 1,257 lbs.
In more recent years, the manufacturing side of the business was sold by Watson’s original Birkin Cars company to Birkin Performance Cars, owned by Ralph Smith and Dean Knoop. That company acquired exclusive rights to manufacture the current Birkin product range and all the preceding models under license to Birkin International, for all markets excluding North America and Canada.
In those territories, Tom Carlin’s Birkin Direct USA continued as the exclusive importer and distributor. Watson himself stayed on in a design, development, and consultancy role.
The Birkin S3 has earned a place alongside the Caterham and Westfield as one of the most respected Lotus Seven-derived cars in the world, it’s a remarkable legacy for a project that started with one man, one workshop, and a car he initially built just for his own enjoyment.
The Hayabusa-Powered Birkin S3 Shown Here
This Birkin S3 is a left-hand-drive Lotus Seven replica powered by a Suzuki GSX1300R Hayabusa-sourced 1,298cc inline-four mated to a 6-speed sequential transmission. This engine is good for 175 bhp at 9,800 rpm and 104 lb ft of torque at 7,000 rpm.
The car was acquired as a kit in 2004 and assembled by Roger Hamlin of Hamlin Fabrication in Petaluma, California, with the build completed in 2008. It’s finished in red over black upholstery and rides on 15″ Kosei K-1 Racing wheels shod with Dunlop Direzza ZIII tires. The aluminum bodywork has a NACA duct in the fiberglass nosecone, a vented hood with carburetor cutouts, cycle-style fenders, and a side-exit exhaust system.
The cockpit is fitted with Birkin-branded bolstered bucket seats, an OMP quick-release steering wheel, an adjustable pedal set, and a roll bar with shoulder belts. Instrumentation includes a SPA Design 12,000 rpm tachometer, a VDO 120 mph speedometer, and additional auxiliary gauges. The seats were refitted with softer foam in 2021, and a removable black soft top and side curtains are included.
The suspension includes an independent front setup with rack-and-pinion steering and a live rear axle, with adjustable coilovers at all four corners and four-wheel disc brakes.
The suspension includes an independent front setup with rack-and-pinion steering and a live rear axle, with adjustable coilovers at all four corners and four-wheel disc brakes. A Speedway Engineering quick-change rear end with a limited-slip differential was installed in 2021 along with a Power Commander wideband system, an 11mm clutch master cylinder, fuel tank and driveshaft modifications, and a gear set change.
It’s now being offered for sale out of Costa Mesa, California with a California title describing the car as a Specially Constructed Vehicle with no model year. If you’d like to read more about it or register to bid you can visit the listing here.
Images courtesy of Bring a Trailer
Articles that Ben Branch has written have been covered on CNN, Popular Mechanics, Smithsonian Magazine, Road & Track Magazine, the official Pinterest blog, the official eBay Motors blog, BuzzFeed, Autoweek Magazine, Wired Magazine, Autoblog, Gear Patrol, Jalopnik, The Verge, and many more.
Silodrome was founded by Ben back in 2010, in the years since the site has grown to become a world leader in the alternative and vintage motoring sector, with well over a million monthly readers from around the world and many hundreds of thousands of followers on social media.
