The Dyno

This is our home built dyno project that can be seen in our YouTube videos that we specifically built to be able to dyno atv's. Our dyno is capable of reading up to roughly 150 WHP accurately. While the dyno was designed for atv's that's not the only thing we use it for, we also dyno engines, dirt bikes, street bikes, mowers, go-karts or anything else that will fit on the roller. With that being said if you have something to dyno go visit our Dyno Scheduling page and get scheduled today! If not enjoy the build.

Dyno Scheduling

Components

Inertial Weight

The inertial weight of the dyno comes from both the rollers and shaft as well as the 25hp GE electric motor we used add additional mass to get our desired moment of inertia.

Frame

The frame was built out repurposed c-channel steel, 1/4" steel plate for all mounting pads and 2" shaft bearing blocks.

Rollers

The rollers are built out of 12.75"x18" 3/4" wall steel tube, 1/4" steel plate, 4" hot rolled 4140 round bar and are straight knurled for traction.

Controls

The dyno uses an arduino uno in combination with a 2STROKESTUFFIN ARDYNO shield board and a magnet/ha sensor for rpm pick up.

Capability

Due to the use of the steel rollers and the electric motor the moment of inertia of the roller assembly is high enough to allow us to read power up to around 150 whp accurately. While the dyno is able to read up to said power for more accurate reading of lower power equipment the electric motor can be disconnected from the roller shaft which decreases the moment of inertia. Benefits of this system and its engineering are that we are able to change the effective load to provide a reasonably accurate running scenario to allow for tuning of realistic running conditions.

Accessories

Using the Ardyno board we have several programable channels we can use to add in overlay in the SimpleDyno software to allow for better data correlation. Standard data acquisition equipment we like to use are indictive spark probes, wideband o2 sensors, egt sensors and coolant temp sensors. Typically the best tuning tool for power sports equipment is exhaust gas temp as it provides the best accuracy for engine running conditions but consequently is the most invasive as requires modifications to exhaust to properly locate the sensor on the exhaust. As a second best to egts we use a wideband o2 sensor which is equipped with a sniffer tube which can be inserted into the exhaust outlet and requires no exhaust modifications to use.

Advanced Tuning

Thanks to fact that the electric motor we used for the dyno is still in operable condition we can use some special techniques to create some advanced tuning advantages found few other places. Long story short by essentially "injecting power" into the electric motor we can create an additional load similar to what would found on an eddie brake dyno or water brake dyno. The advantage to using this added load is we can recreate conditions like low rpm bogging you would see while climbing hills where the engine is being held at WOT but rpms are remaining constant or dropping and expose hard to find hiccups in engine tuning in hard to recreate tuning conditions. When combined with our various data acquisition points we can quickly determine the cause of an issue and resolve it with out trial and trial and error issue hunting. Also this added load is variable so it can be adjusted to specific vehicles and be actively adjusted to repeatedly sweep problem areas.

Specifications

Given the width and diameter of the rollers we are able to fit any motorcycle or 2wd capable atv from blasters to drag quads. Dyno rollers have an 18.5" knurled OD providing optimal traction for powersports sized tires. We keep a special set of dyno specific wheels and tires in house for use with honda, suzuki, yamaha and kawasaki atvs. Dyno computing is done within SimpleDyno 6.5.1. Data capabilities include engine rpm, roller rpm, exhaust o2, egt, coolant temp, back pressure sensors, engine power, wheel hp, wheel and engine torque. Extra data acquisition can be provided at special request.