WardEnterprisesRacing HO Dyno "Dynamometer"

The WER HO Dyno is a compact dynamometer designed specifically for HO scale slot cars, giving racers and builders a practical way to compare power output, amp draw, and the effect of tuning changes at the rear wheels.

Updated WER Precision Roller Design: All WER HO Dynos now include our new black precision-machined roller for improved smoothness and consistency. Prior WER Dyno owners have also been offered a complimentary roller upgrade so earlier units can be brought up to the latest WER standard.

Our dyno is not simply an RPM readout device. While RPM can be useful when comparing armatures, it does not tell the full story when trying to measure the overall power output of a complete slot car. On the WER Dyno, the rear wheels drive a roller inside the box that is directly connected to a small micro-motor. This micro-motor acts as a load on the rear wheels and also functions as an electrical generator, sending a signal to the Power Output display.

That electrical signal is converted to the number shown on the display. The number varies based on how much power is generated at the rear wheels of the car, and that output can be affected by motor performance, gearing, tires, chassis setup, and downforce from traction magnets in inline magnet cars.

The WER HO Dyno is the result of extensive development and ongoing refinement to provide HO racers with a compact, rugged, and useful tuning tool. The latest WER version includes our new black precision-machined roller, developed to run truer, smoother, and more consistently than the previous roller design. Each roller is machined as a precision part rather than simply used as supplied material, allowing better control of roundness, surface finish, and smoothness in operation.

Special attention was given to provide a platform that allows magnet cars to “pull down” on the roller platform to simulate conditions seen on track. This is an important feature of the WER Dyno and helps provide a more accurate and repeatable measurement for magnet cars.

The WER Dyno features a 4-digit measurement for power output, often referred to as the “dyno number,” as well as motor amp draw and voltage input through the separate power supply readout. Using the dyno number allows HO slot car builders and racers to measure the results of tuning changes made to the chassis, motor, gearing, tires, and setup.

The dyno can be powered by the included 3–24V variable power supply plugged into a 120V outlet, or by the two internal 9V batteries that deliver approximately 18 volts when a power outlet is not available. This is particularly useful on race day when access to a wall outlet may be limited. The included power supply is rated at 72W / 3A.

Dyno dimensions are approximately 3.5" x 4.5" x 1.5" tall. Its compact size makes it easy to keep on your home workbench and easy to carry in a pit box on race day.

Tested extensively with everything from stock Aurora T-Jets to HOPRA Modified cars and many platforms in between, including TFX, Magnatraction, Fray race cars, Spec Racers, Super Stock, Fusion, Ghost Car, Auto World ThunderJet, XTraction, Four Gear, Super III, 440x2, Harden Creek Super 7, and other HO slot car platforms. Please note that cars need to have guide pins installed; slot cars with guide flags will not fit on the dyno.

The WER Dyno comes complete with full instructions and suggestions for use, along with a 2A variable power supply as shown in the listing photos. The unit also includes two installed 9V batteries, which are easily changed by the owner when needed.

Please note: any flickering shown in listing videos is due to video recording. The actual unit display does not flicker during use .

Want to get the most out of your WER HO Dyno? Read our tuning guide: How to Use an HO Dyno to Tune Your Slot Car for Race Day →