Quote:

FINDINGS: Zooming in down below 100Hz and increasing the FFT integration size you can clearly see the 1st harmonics in exhaust noise. Top RPM was about 4800 in each of the three gears. Second gear might be slightly higher (4830RPM) and Third gear (at the finish line) a little lower (4770RPM). Many higher-order harmonics can also be seen and carry additional useful information. (These are all conservative guesses on the low side and could be higher by 20 or 30 RPM.)



I never thought I'd see a thread on FFT on Moparts. Since the exhaust cycle only happens every other revolution on a 4-cycle engine (they are running Hemis as 4-cycles still, aren't they?), I guess you can double those numbers to come up with engine RPM.

$100 for 100 HP. Someone's dreaming of a BIG Christmas present. Closer to $100k for 100 HP and that would still be cheap at that level.

Floyd Lippencott IV