Tuesday, May 1, 2007

The importance of power benchmarking

Team Fruity has been asked on many occasions, "Why do you use a software dyno and not an actual dyno? Isn't a normal dyno more accurate?"

There are many reasons for choosing a log analyzer to compute power and torque:

  • Firstly, dynos, even of the same brand and model, rarely ever perform the same as each other. Depending on how the dyno is calibrated by the shop, it can either be too high or too low. That is why so many disputes arise over why one person's tune seems to be 'unusually high'
  • Secondly, dynos rarely are accurate on a day by day basis when they are regularly used. Regular maintenance and calibration on the part of the dyno shop is expected, but rarely adhered to. That is one reason why some dyno charts read differently from day to day on the same car.
  • Thirdly, dynos vary from shop to shop, there are so many brands of dynos, some measuring from the engine, others from the wheel. Some have more rolling resistance, others have less. And so on.
Fundamentally, few dynos are rarely accurate enough to measure power and torque, given the many factors that play a part in dyno accuracy. Dynos, are, at best, tools used to compute gains and impact in power and torque as a result of tuning.

By using a single consistent means of measuring performance gains from tuning, using a common software tool, no matter where tuning is done across the world, Team Fruity is able to apply a universal measure to its cars to show gains from the now-famous Banana Tune.

Thus, it does not matter whether 350 is read as bhp or whp. The ever-important factor is to study the area between the curves, to see where gains in useable power and torque have been found. Most people make the mistake of only being obsessed about peak power and torque.

That is not the JDM way.

Side note: Tonight, 1 May 2007, in a friendly race, a JDM Evo IX GT tuned and rated by Team Fruity at only 350 bhp, outran a JDM Evo IX GSR dyno'ed at over 440 bhp. Q.E.D.