The Dyno is a simplified version of the DL90, and mostly used for power runs to work out bhp at the wheels. The DL90 can do that as well a g-force and sector times, and circuit layout it determines from the GPS data. So once the data is processed on the PC, you can have a map of the circuit, overlayed with your position, along with speed, g-force, plus whatever you chose to input into the other inputs (2 analogue inputs (can read from any 5V or 12V source, so it can be connected to the coil) + 1 digital (with adjustable threshold)). The traction circle graph it produces is massively useful. The Dyno can record 5 minutes worth of data, whereas the DL90 can record 90 minutes data (with 100 measurements per second).