Drag Racing Gear Formulas

[1sicklx]

Formula for max mph with gears:
(tire height x rpm's) / (gear ratio x 335)

Formula to tell if you have the right ratio for the 1/4:

ET x MPH= 1335, if higher than 1335 you need more gear, if lower you need less.

Ran across this and thought I'd share. :popcorn:

[QWKSNKE]

Check and see but i think that maybe one of the calculators in the FAQ section here :shrug:

[1sicklx]

Close but different

[slvrbullit]

I guess I need more gear then.

Both my nitrous and N/A time = higher than 1335.

[1sicklx]

The more I mess with this the more I find it's pretty general and doesn't seem to take into account things like traction/60' times .. I think that the person that came up with this was basing it off of a perfect launch on slicks.

[1sicklx]

Discovered that these formulas were pulled from the FTI site as follows:

Compute the Ideal 1/4-Mile Pass


Elapsed Time X MPH = 1335
Examples:
13.35 x 100.00 MPH = 1335
12.00 X 111.25 MPH = 1335

If the factor is more than 1335, add more rear gear.
If the factor is less than 1335, reduce rear gear


How to Compute Your Miles-Per-Hour


MPH = TD X RPM / GR X 336
MPH = Mile Per Hour
TD = Tire Diameter
GR = Rear Axle Gear Ratio
RPM = Engine Revolutions Per Minute