Originally Posted by BlackRamHemi
Old Tire size/ New Tire size x Gear ratio = effective gear ratio
My truck cam stock with 275/60R20's 933" Tall) and 3.55 Gears
When I mount my 275/45R17 927.5" tall Drag Radials for a day at the track
My effective gear ratio is about 4.25:1
33/27.5 = 1.2 x 3.55 = 4.26:1
...all together = about 5 tenths (a half second) quicker over a quarter mile.
Could you explain the equation in more detail for me Please?
Is it tire height divided by ? = 1.3 X the rear ratio = calculated rear ratio?