tire x gearing x rpm x speed guide?

[wishIhada5.0]

Is there a chart out there for our trucks with the ZF5 to cross reference gearing, with tire size, rpm, and speed?

[BigFuel]

I don't know one but like any good teacher I can show you how to find it yourself.

To find actual speed all you need is tire radius, R&P gear set, and engine RPM. The formula looks something like this:

[RPM / R&P gear set] x 2[pi]r{where r is the actual radius (not the advertised) of the drive tire}

To use assumed numbers:

1000 rpms
4.10 rear end
31.5" drive tire (some folks on here are not using the same tires front and back so only measure the rear tire)

(This is in 4th gear which is 1:1 so this eliminated having to calculate for it)

[1000 / 4.10] x [2 x 3.14]15.75" = (simplified below)

[243.902] x [98.91" (inches traveled per 1 tire rotation)] = 24,124.34682" per minute.

Clean up:

24,124.34682" / 12" => 2,010.362235' per minute x 60 (minutes) =120,621.7341'/hour

Clean up:

120621.7341' / 5280' (feet in a mile) = 22.845 MPH Roughly 23 MPH

Clear as mud?

[ratt396]

4x4 related Calculators, Crawl Ratio, Gears Tires Sizes, etc..
Ck that one out its got a lot of different calculators

[BigFuel]

Bookmarked, Nice link Ratt

[ratt396]

Thanks yeah found that when I was trying to figure out my whole tire issues on what would work and what wouldn't and saw it had some other good stuff on there.

[Karls03]

There are easier formulas that don't require Pi, just make sure you calculate your desired gear properly.

RPM=(speedxgearx336)/diameter
Speed=(diameterxRPM)/(gearx336)
Gear=(diameterxRPM)/(speedx336)
Diameter=(speedxgearx336)/rpm

There, simple math, no internet required.

sent from a dumb guy with a smart phone

[wishIhada5.0]

Thanks guys!