<VV> Semi OT- basic math

[Dale Dewald]

At 15:29 8/27/2010 -0400, CJ Wilson wrote:
>Okay, so here's a weird little question... I *think* I
>know the answer to this, but everyone please double-
>check, cause some days I just can't do math....
>
>Assuming I know my rear-tires revolutions-per-mile
>number, can't I guesstimate my RPM's at 60 MPH by
>just doing revs-per-mile times transaxle gear ratio?

Yes, but you can do more than guess.

>Because at 60 I'm doing a-mile-a-minute, so my tires are
>turning-over the revs-per-mile # in a minute... equals
>revs per minute of the TIRES. Times tranaxle ratio=
>rev's per minute of the ENGINE... right?

Yes.

For example, tires with 840 rev/mile and a 3.55:1 axle ratio:

3.55 X 840 = 2982 RPM @ 60 MPH

Dale Dewald
Hancock, MI