When analyzing the function of our favorite test tool, the Dynojet dynamometer, horsepower is measured by the rate of time a vehicle takes to spin the Dynojet roller, based on the roller's weight.
A Dynojet is equipped with a magnetic pick up that mounts to the roller's shaft, which provides the needed data. Using this same concept, Blitz allows the user to plug in a vehicle's weight (with driver) to represent a dyno's roller weight. The Power Meter also replaces the Dynojet's roller magnetic pick up with the vehicle's vehicle speed sensor.
The result is an on-board dyno that can calculate horsepower and if the unit is run through the proper set-up procedure, horsepower will be calculated at the flywheel, rather than at the drive wheels. Horsepower can be viewed in three different modes: graphical power, digital power and power vs. speed. While in digital mode, not only can the readout be viewed in bar graph form, it is also shown numerically, including a max net horsepower peak/hold feature. By using the "Up" and "Down" arrows, the horsepower bar graph can also be displayed in outputs as high as 1,200 hp. Power can be viewed in five different readout modes: 0-200, 0-300, 0-400, 0-800 and 0-1200. (Since the Power Meter screen is so small, the 1-200 screen will have better resolution than the 0-1200 screen.)
If graphical mode is preferred, a line graph will appear when the vehicle is in motion. For instance, let's say you started the graph at a steady speed. The line graph will show your horsepower in real time throughout each gear change and as well as the throttle percentage as you accelerate.
If the vehicle comes to a complete halt, the graph will stop until the vehicle is in motion once again. Think of this mode as an EKG scan that monitors horsepower fluctuation. Graphical mode will also allow the user to view power in numerical form in real time, including a peak/hold feature that displays the vehicle's highest horsepower reading.
The last mode that can view horsepower is the chassis dyno mode. This mode allows the user to view power vs. mph. This screen is also viewed in real time and can be used to analyze horsepower in different gears. (This information can be used to dial-in the scramble boost mode of the Dual SBC controller) Selecting through the "Enter" button will also allow the user to view peak/hold horsepower readings.
Dash ModeAn added bonus to the Power Meter is its ability to record various time trials. By entering "Dash" mode, the user can record various types of runs from 1/8, 1/4, 5/8 mile and 0-60 mph. Not only does the unit display the time in seconds for the selected application, it will also show the vehicle's mph.
For 0-60 time trials, the unit starts the clock and is able to record the moment the speed sensor is activated. However, the unit is not able to compensate for wheelspin, so all recorded times must be performed with minimal or no wheelspin. Scrolling down one screen from "Dash" mode allows the user to review the last six runs recorded, whether it be mph or e.t selections.
TestingAs a quick accuracy test, we decided to install the Power Meter on a '91 Toyota MR2 Turbo. Installation consisted of locating a visible mounting point and connecting the following three wires: ignition power, ground and speed sensor signal. We decided to consult the factory service manual to access the factory ECU wiring for all three wires. Since our test vehicle is an MR2, the ECU is located in the trunk, which meant we had to run our wires from the driver's seat through the engine bay and into the trunk. In other words, we had some long-ass wires. Once we had the meter installed, it was time to program the weight.