4WD – BPA-4R S

S series comes with knurled rollers as standard, which provide the highest traction between rollers and tires, a guarantee of an extremely accurate measurement. Specifically designed for standard cars’ workshops, test lanes.
This series has lower performances if compared to our HP (High Performance) Series, but maintains the same accuracy and balanced top level components.
Axles synchronization: 
Electronic linked and synchronized axles through software, made by fast and precise high frequency control of eddy current brakes, with the aim to synchronize the axles in a 4wd car (Bapro’s patented system). 
This function avoids any differentials damage and helps to carry on more accurate tests, because wasted power due to slippage inside the differentials is avoided too. 
Thanks also to this, BPA-4R S dyno is extremely easy to be installed and maintenance is almost absent.

✔️ Used by electric vehicles’ manufacturers


Mechanical features:

  • Roller diameter: 240 mm
  • Roller width: 660 mm
  • Balance quality grade G 2.5
  • All the mechanics is laser aligned
  • Overall dimensions mm: 4160 x 3130 x h. 360
  • Max weight per axle: 2.000 kg


  • Maximum speed: 250 km/h
  • Maximum measurable power: 800 HP (400 HP per axle)

Power supply:

  • voltage (Dyno) single phase  230 VAC
  • voltage (Fan cooling system) 3/N/PE 400VAC
  • frequency 50 Hz
  • fuses 16 A
  • compressed air 6 bar


  • Shorter repair time (fast and exact diagnosis)
  • effective use of the instruments already present in workshop (diagnosis equipment, gas analyzer)
  • Avoid any risks from road tests (traffic, accidents, fines)
  • Results certification (performance enhancement)
  • Accessories sale improvement by result verification (exhaust systems, efi controller etc..)
  • Second-hand vehicles sale improvement by engine health certification
  • Vehicle check before second-hand trades
  • Renting for tests and technical checks

Measuring program:

  • Transmission verification (clutch slippage)
  • Power step test
  • Power sweep test
  • Cooling system check (radiator, fan sensor, thermostatic valve)
  • Diagnosis by gas analyzer under load
  • Vehicle test with constant speed
  • Vehicle test with constant force
  • Vehicle test with constant load
  • Road simulation (slope, drag resistance, weight)
  • Vehicle test with constant RPM
  • Durability tests
  • Engine mapping to all RPM
  • Diagnosis by scantool during road simulation
Standard features
  • 2 Eddy currents brakes, 8 rollers knurled over the entire width, finished by cut knurling
  • Electric adjustment of vehicle wheelbase; pneumatic vehicle lifter, with integrated rollers lock
  • Fully functional management software
Optional features
  • Double ventilation system movable on wheels, target power 6 kW, flow rate 44.000 m3/h (4 kW optional)
  • Single ventilation system movable on wheels, target power 3 kW, flow rate 22.000 m3/h (2 kW optional)
  • Lambda kit: 5 wires wide band Lambda probe and controller
  • Boost pressure input 0÷2.5 bar relative pressure ± 0.035 bar error. (Requires outer meteo sensor box)
  • Lambda Input connect a vehicle lambda probe with an external controller (Outer meteo sensor box)
  • High width aluminum loading ramps. Needed when the dyno is installed on ground.
  • Computer trolley built by heavy duty lasting steel, Pro: heavy duty, movable, wide working surface
  • Proportional ventilation speed control adjusting the fan speed in function of the rollers speed
  • Infrared remote control test bench management directly from vehicle cockpit
  • Roller covers protect the rollers when the dynamometer is not working
  • Personal computer and display
  • Safety Equipments: Side safety barriers with logo panels, Anchoring ratchet straps, High attenuation ear muff
  • OBDII parameters reading and dtcs deleting without the need for additional hardware and dedicated interfaces.

Optionals in details

Comparative table
Maximum speed 360 km/h 360 km/h 200 km/h 250 km/h 250 km/h
Maximum adsorbable power 650 HP 1300 HP 400 HP
Maximum measurable power 1000 HP 2000 HP 900 HP 400 HP 800 HP
Maximum traction force 8000 N 16000 N 16000 N
Mechanical features
Rollers diameter 400 mm 400 mm 400 mm 240 mm 240 mm
Rollers width 700 mm 700 mm 700 mm 660 mm 660 mm
Roller balancing grade G 2.5 G 2.5 G 2.5 G 2.5 G 2.5
Equivalent base inertia 450 Kg 900 Kg 550 Kg 240 Kg 480 Kg
Dimensions 3470×1135 mm 4360×3470 mm 3470×5300 mm 3070×870×310 mm 4160×3130 mm
Deck height 410 mm 460 mm 640 mm 360 mm 360 mm
Weight 2500 kg 2500 kg 2000 kg 2000 kg
Voltage 400 V 50 Hz 3/N/PE 400 V 50 Hz 3/N/PE 400 V 50 Hz 3/N/PE 220 V 50 Hz 1/N/PE   220 V 50 Hz 1/N/PE  

Car Dynos 4WD – BPA-4R S - Basic Configuration