Bovensiepen Spider Brings the BMW Z4 Back With 435 HP
BMW may have ended production of the Z4, but the story of the German roadster is not quite over. The new Bovensiepen Spider brings the two-seat sports car back in a limited-run form, combining the familiar BMW straight-six with more power, bespoke chassis tuning and extensive handcrafted upgrades.
Built in Buchloe, Germany, the Bovensiepen Spider produces 435 hp and 580 Nm from its 3.0-liter turbocharged inline-six. Just 99 examples will be built, making this one of the most exclusive modern interpretations of the BMW Z4.
The Spider is the third model from Bovensiepen, the company continuing the automotive legacy of the Bovensiepen family after the end of the original Alpina era. Like the brand’s other cars, it combines BMW engineering with extensive mechanical and visual modifications.
The Bovensiepen Spider Is a BMW Z4 Reimagined
The connection to the BMW Z4 is obvious beneath the surface. Bovensiepen does not simply add a few cosmetic parts to the roadster. The Spider receives a redesigned exterior, revised suspension tuning, upgraded wheels and tires, improved cooling and additional structural reinforcement.
The result is intended to feel less like a conventional tuned car and more like a handcrafted limited-production sports car.
That philosophy is reflected in the car’s proportions. The Spider retains the classic front-engine roadster formula with a long hood, a rearward-set passenger compartment and short overhangs.
The exterior design was developed together with Frank Stephenson Design, the designer also involved with the Bovensiepen 05 GT.
Classic Roadster Design With a Modern Bovensiepen Identity
The Spider receives a number of visual changes that separate it from the standard BMW Z4. At the front, there is a gloss-black splitter with twin extensions, while a black design line runs around the body.
Editor’s Choice
Other distinctive details include:
- large air outlets in the front fenders,
- bespoke side skirts,
- a redesigned rear diffuser,
- an integrated rear spoiler,
- 20-inch forged Bovensiepen wheels with 10 twin spokes.
The forged wheels are not purely a styling exercise. Their relatively low weight helps reduce unsprung mass, contributing to the Spider’s handling and steering response.
BMW’s 3.0-Liter Straight-Six Now Makes 435 HP
Under the hood sits a 3.0-liter turbocharged inline-six producing 320 kW, or 435 hp, and 580 Nm of torque.
The engine remains one of the defining features of the Spider. Rather than simply chasing a bigger peak power number, Bovensiepen focused on improving the way the engine breathes and delivers its performance.
The result is a power-to-weight ratio of just 3.6 kg per horsepower.
Ram Air Intake and a New Sports Exhaust
Bovensiepen modified both the intake and exhaust systems. The intake air duct has been optimized and extended with an additional ram-air channel, while the intake silencer has been enlarged and optimized for airflow.
The sports exhaust system has also been revised to improve airflow and reduce exhaust back pressure. According to Bovensiepen, the changes provide the technical foundation for the increased output while also giving the roadster a more emotional soundtrack.
Bovensiepen Spider Performance: 4.2 Seconds to 100 km/h
- Power: 435 hp
- Torque: 580 Nm
- 0–100 km/h: 4.2 seconds
- Top speed: 260 km/h
- Top speed with Performance Package: 295 km/h
- Transmission: 8-speed automatic
The eight-speed ZF automatic transmission sends power to the rear wheels. In Sport mode, Bovensiepen says gear changes take approximately 0.1 seconds, while steering-wheel paddles allow the driver to take control of shifting.
There is, however, one notable omission for purists: the Spider is automatic-only. There is no manual transmission option.
The Performance Package Raises the Top Speed to 295 km/h
Customers looking for more high-speed capability can order the optional Performance Package.
The package includes a milled aluminum rear differential cover with larger cooling fins, helping reduce thermal loads under heavy use. It also adds an optimized underbody reinforcement with a V-brace, increasing structural rigidity and contributing to a more precise chassis response.
With the package installed, the Spider’s electronically limited top speed increases from 260 km/h to 295 km/h.
Suspension Tuned for More Direct Handling
Bovensiepen has also reworked the chassis rather than focusing solely on engine output.
The suspension features newly tuned dampers, with increased compression damping at low damper speeds. Longer auxiliary springs on the rear axle are designed to create a more direct connection between the body and chassis.
The Spider rides on Michelin Pilot Sport 4 S tires mounted on forged 20-inch wheels.
- Front: 9 x 20-inch, 255/35 ZR20
- Rear: 10.5 x 20-inch, 295/30 ZR20
An optional high-performance braking system adds four-piston fixed calipers at the front together with larger ventilated and drilled brake discs.
1,585 kg and 281 Liters of Luggage Space
According to the preliminary manufacturer specifications, the Bovensiepen Spider has a DIN kerb weight of 1,585 kg. The EC unladen weight is listed at 1,660 kg.
The roadster measures:
- Length: 4,334 mm
- Width: 1,864 mm
- Height: 1,304 mm
The luggage compartment offers 281 liters of capacity, giving the two-seat roadster enough practicality for a weekend trip.
Fine Driving and a Handcrafted Interior
The interior follows Bovensiepen’s Fine Driving philosophy, combining BMW-based technology with extensive customization possibilities.
Standard equipment includes Vernasca leather and Alcantara upholstery, a steering wheel wrapped in Lavalina leather, heated steering wheel, Comfort Access and a Harman Kardon Surround Sound System.
Customers can go considerably further through the Bovensiepen Saddlery program. Lavalina leather can be extended across the dashboard and other interior surfaces, while Alcantara can be used on areas including the A-pillars and rollover hoops.
Every Spider also receives an individually numbered plaque, reinforcing its limited-production character.
Only 99 Bovensiepen Spiders Will Be Built
The most important number may not be 435 or 580. It is 99.
Only 99 hand-built examples of the Bovensiepen Spider will be produced worldwide. The standard production allocation is divided between five exterior colors:
- Sapphire Black: 40 cars
- Sanremo Green: 25 cars
- Skyscraper Grey: 20 cars
- Thundernight: 9 cars
- Frozen Grey II: 5 cars
Customers can also order an individual exterior color through Bovensiepen’s personalization program.
How Much Does the Bovensiepen Spider Cost?
The starting price in Germany is €115,500 including 19 percent VAT. Orders are already open, while the first customer deliveries are scheduled for the first quarter of 2027.
That makes the Spider considerably more expensive than the BMW Z4 on which it is based, but Bovensiepen is selling something different: a hand-built, individually configurable collector car limited to fewer than 100 examples.
The Z4 Deserved This
Bovensiepen Spider: Key Facts
The Bovensiepen Spider is a limited-production two-seat roadster based on the BMW Z4. It uses a 3.0-liter turbocharged inline-six producing 435 hp and 580 Nm. The car accelerates from 0 to 100 km/h in 4.2 seconds and reaches 260 km/h, or 295 km/h with the optional Performance Package.
Only 99 hand-built examples will be produced worldwide. The German starting price is €115,500 including VAT, with first deliveries scheduled for the first quarter of 2027.
Frequently Asked Questions
What engine does the Bovensiepen Spider use?
The Bovensiepen Spider uses a 3.0-liter turbocharged inline-six producing 435 hp and 580 Nm of torque.
Is the Bovensiepen Spider based on the BMW Z4?
Yes. The Spider is based on the BMW Z4 platform and extensively reworked by Bovensiepen with bespoke exterior design, chassis tuning, wheels, brakes and interior finishes.
How many Bovensiepen Spider cars will be built?
Production is limited to just 99 hand-built examples worldwide.
How fast is the Bovensiepen Spider?
The Spider accelerates from 0 to 100 km/h in 4.2 seconds. Top speed is 260 km/h, increasing to 295 km/h with the optional Performance Package.
How much does the Bovensiepen Spider cost?
The starting price in Germany is €115,500 including VAT.
When will Bovensiepen Spider deliveries begin?
The first customer cars are scheduled to be delivered in the first quarter of 2027.
BMW may have ended the Z4, but Bovensiepen clearly wasn’t ready to let the roadster disappear. With 435 hp, a BMW straight-six, rear-wheel drive and only 99 examples planned, the Spider could become one of the most interesting collector roadsters of its era.
