Street Dyno

The ECU+ includes an integrated street dyno feature that gives you the ability to see what kinds of horsepower and torque your car is making without spending hundreds of dollars on a "real" dyno. (How accurate is it? pretty darned accurate.) It works like this:

Zooming in

Now that you've got a datalog captured, open that up using the Windows software. Zoom all of the way out and use the handy New! Zoom X Axis->Next WOT Region menu item. This jumps to the full-throttle section of the log and zooms in on it.

Next, bring up the ECU+'s street dyno feature by right-clicking on a graph, and selecting Analyze->As a Dyno Pull. Poke in your car's weight and tire size, and hit Calculate. You'll now have an accurate estimate of the plot that you'd get if you had a real dyno in your living room.

A street dyno plot

As with all of the other graphs in the ECU+ software, you can zoom in and pan around the dyno graph to your hearts content, and when you've got just the right view, hit File->Print to print out your dyno plot.

With the ECU+ street dyno, an always-on cursor shows you the horsepower, torque and New! air-fuel ratio for any given RPM. The cursor also New! tracks back to the normal time-based graphs. This is a simple, yet incredibly powerful feature: if you see a dip in the torque curve, simply move the dyno cursor to that dip, and look over to the time-based graphs. You'll find the time-based cursors on the exact time when that torque was being generated. If there's a high knock spike or lean-out condition, you'll see it immediately and can take corrective action.

Two street dyno plots

Still not convinced of the usefulness of ECU+'s street dyno feature? Try this: make a change to the fuel curve of your car, then make another run. Once stopped, open the second run on top of the first run, and do another dyno analysis. You'll end up with something like the plot on the right.

The ECU+'s street dyno shows you exactly how well your tuning has done by overlaying the two runs right on top of each other. With this powerful capability, and a long stretch of open road, you can make incremental tuning improvements to your car without spending hundreds of dollars on dedicated dyno time. After just a few street dyno sessions, the ECU+ will come close to paying for itself.