In the first article I spoke about the smooth fell in the engine and a little better fuel economy. Also, I felt dyno runs would be necessary to get the real picture. I finally found the time (this darn day job just interferes with my chosen lifestyle) to get to a dyno.
The EV is set to factory specifications for the throttle position sensor (TPS) and %CO. All temperature sensors have been checked for accuracy and out of tolerance sensors were replaced. Air bypass screws are open about one-half turn. A K&N replacement element air filter and California II crossover have been installed.
Several runs were made with the stock chip. These runs had a serious glitch in power delivery around 5000 rpm. The maximum power with the stock chip was 60.8 hp and maximum torque was 56.9 at the rear wheel. Also the successive gear change runs indicated an extremely, overly rich condition over 4000 rpm as evidenced by the trailing ramps on the dyno graph and as observed out the tail pipes.
The Misano Chip was installed and comparable runs performed. Where the stock chip floundered, the Misano chip did not - showing a 5 hp increase at that point on the graph. Maximum power is slightly increased to 62.1 hp and maximum torque increased to 58.7 at the rear wheel. Also interesting to note - below 4000 rpm, the graphs were identical to the stock chip, the only difference appeared at over 4000 rpm. The Misano Chip also produced rich runs in the gear change runs, but only by the graph and not the tail pipe.
Fuel mileage with the stock chip had been a consistent 43 mpg. The Misano Chip has been delivering 44 mpg in colder air temperatures which tend to decrease fuel mileage.
The dyno runs indicate that both factory and Misano Motors need to return to the drawing board. Although the Misano out performs the stock chip, leaning out the top end (over 4000 rpm) would produce better power delivery. As the old tuners adage goes, lean is mean and fat is lazy. While it is true that an approximately 10% over stoichiometric mix provided better power, both of these chips were just too rich, resulting in power drop off as shown by the dyno.
A possible solution may be to reduce the TPS reading for a given position by about 10 mV and try a few dyno runs again. Lowering the TPS voltage will give the computer false readings as to the actual position of the throttle and should result in a shorter duration when the injectors are open. As always, this will have to wait for when I have the time.
Should you purchase this chip? There are power and torque increases that result from just replacing the chip. If you are getting poor mileage, replacing the chip won't help you. Your machine must be set up properly. In my opinion, getting rid of the power glitch was worth the price of admission.