So what exactly is CarBahn, and why does it matter in the context of a 735-horsepower BMW M4 Competition?
CarBahn is Steve Dinan’s latest venture after selling his previous company, and its mission is refreshingly specific. Instead of chasing internet-breaking lap times or headline numbers, the focus is on balance, function, and refinement. This particular CarBahn BMW M4 happens to be Dinan’s personal car, making it a direct expression of that philosophy.
Complete Powertrain Information
CarBahn M4 uses a 3.0-liter inline-six twin-turbocharged engine, which produces a whopping 735 horsepower and 668 lb-ft of torque. This was all possible with the tuner’s CarBahn Stage 2 power kit, which includes some important mechanical goodies like upgraded primary heat exchange, upgraded intake, exhaust system, and a supporting tune.
The CarBahn M4 also uses a stock all-wheel-drive torque distribution and eight-speed automatic gearbox. As for performance figures, they are predictably dramatic
The CarBahn M4 has a top speed of 190 mph and a sprint from 0 to 100 km/h in an impressive 2.8 seconds. This personal record was also achieved thanks to the car’s new mechanical tweaks mentioned above.
Other Specifications
Chassis tuning is where this M4 truly separates itself. The suspension setup is built around the stock adaptive dampers, paired with custom springs and sway bars.
Considerable development time went into tuning the bump stops, which use a progressive rate rather than the linear-rate stiffness of the springs. The result is improved control over suspension travel without compromising composure.
Additional hardware includes spherical front control-arm bushings, sealed spherical rear toe-link bushings of the Lemförder type, and a five-point carbon-fiber front strut-tower brace. Although described as a coilover system, the suspension is technically a height-adjustable spring setup using the factory dampers. Both sway bars are four-position adjustable.
The sports car is also wrapped in Michelin Cup 2R tires, measuring 295 mm up front and 305 mm at the rear. This provides increased grip on the track. Also, curb weight is set at 3,881 pounds with seating for four occupants.
Pricing
As for pricing, this CarBahn M4 by Dinan tuner has a starting price of $127,744. This is the base price for Stage 1. The tuner is also offering the CarBahn Stage 2, without the carbon-fiber aero components, which comes with a price of $20,599, the stage alone.
Conclusion
The CarBahn BMW M4 Competition is less about spectacle and more about execution. It feels deeply integrated, carefully tuned, and intentionally restrained. Rather than rewriting what the M4 is, it refines what already works—quietly, methodically, and with clear purpose.
BMW CarBahn M4 by Dinan – Photo Gallery
