Basic formula is: speed of sound = wavelength * frequency, which means
wavelength = (speed)/(frequency)
Quarter wavelength = wavelength/4 (as one would guess)
Speed of sound is from
http://www.sengpielaudio.com/calculator-speedsound.htm
(obtain speed from deg F, and in ft/sec)
Engine speed of revolution given as 2000 rev per min which (when divided by 60 sec/min) is 33.33 rev/sec
Firing frequency = (Number of cylinders)/2(four cycle engine) with V8 = 4
So exhaust fundamental frequency is 33.33 * 4 = 133.33 or about 134 Hz
So quarter wavelength = (1520(speed in ft/sec)/134) * (12"/ft) / 4 = 34", for 500 deg F at 2000 rev/min.
I'm just guessing at the EGT. Anyone have a better guess? I was thinking of putting the tubes after the mufflers. Car is a five liter 92, no cats.