Honestly, I may not be able to repeat what Josh and Rob managed to do on the dyno. But I am familiar with the principles behind what was done.
Our goal going into this was to perform consistent runs back-to-back in order to find the gains from the bolt-ons and UpRev tune. We knew that as long as each run was consistent, the absolute numbers for horsepower and torque didn't matter a lot - we only wanted to know what the gains were.
Despite this, we managed to get very accurate readings. Thanks to the computer, which monitored the wheel speed and engine speed, we were able to extrapolate the gear ratio in real-time. After a number of runs, Josh and Rob found a way to accelerate without causing the CVT to change gear ratios.
There are a number of things to keep in mind when dynoing a CVT:
1- When you're in a higher gear (3 through 6) and traveling at less than 30mph, the CVT will downshift if you accelerate too quickly. At approximately 2,500RPM the CVT will upshift back to the selected gear.
2- Going full throttle by pushing the pedal down past the click will cause the CVT to downshift, unless downshifting causes you to redline.
3- The car will upshift automatically just short of redline.
Other than these three scenarios, the CVT stays in the selected gear ratio when in manual mode.
The runs were done in 4th gear. This meant we were not going to get any readings above 6,000RPM. It also required accelerating very slowly at first until we passed the initial downshift threshold. Once we were out and above 2,500RPM the dyno began recording, and the car could be run at 95% throttle without changing gear ratios.
Although we could have theoretically pushed past the click above 4,500 RPM to run at WOT without downshifting, we chose to avoid it for consistency's sake. Our main goal was to find gains after all. A fair guess at the absolute hp and torque numbers at WOT would be to divide the results by 0.95.
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Here's the link to the article, with dyno graph goodness:
http://www.zcarblog.com/
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You'll notice that we lost low-end power with the K&N.And we didn't realize significant gains until we added the y-pipe. Then the UpRev smoothed out the power, and brought the low-end torque up substantially.
The reason I think we lost power with the K&N is because the car is so sensitive to heat. We let the car cool back down to the same temperature before each run. But I think it was still too hot when for the K&N run.
Final numbers after bolt-ons and tune: 221.22whp and 223.78ft/lb torque (SAE factor of 5). If you choose to adjust these numbers for the "click," we get approximately 232.86whp and 235.56 ft/lb torque at WOT. Oh, and the governor was raised to 160mph.
