The lower curve is without nitrous. Its peaks and troughs are smooth but caused by resonance in both tuned length exhausts, and tuned air box volume, designed to give a boost at peak power rpm. The peaks lower down are another consequence of this.## The higher curve is the same curve but nitrous button pushed at 7400 revs, which gives a rather sudden boost.
If you looked at the effective measured gear ratio, during the run it decreases by about 7 percent after 7400rpm. Showing some clutch slip is happening and both wasting power on nitrous and heating up the clutch, which would fail suddenly after a few runs after it overheated. Stronger clutch springs (only 2 from the 6) cured that.
Resonances happen at half, quarter, etc wavelengths. If it reved twice as high you would see 6