Sure, the rear end ratio would be included if one is measuring
the total gear ratio from the crankshaft to the wheel. That would
be the transmission ratio multiplied by the differential ratio.
For example, in my RX-7 1st gear is 3.483 and 4.1, which amounts
to 14.2803, which means 225 ft. lbs. at the crank is converted to
3,213 ft. lbs. at the wheel. Incidentally, divide that torque by
the wheel radius, divide by the mass of the car and you have more
than 1 g of acceleration in 1st gear which thanks to lofty rotary
redlines goes to just over 40 mph.
Too bad I can't get it into 1st when it's rolling anything faster
than 10 miles per hour.
Pat Kelly wrote:
>
> Then you toss in the rearend ratios. For instance, for years we ran a
> 4:55 rear. When we rebuilt the car, we went to a shorter (4:88) and
> found we had to shift too often, losing time. So we went to a 4:11
> because the new engine pulls so well, and heaven has arrived, at least
> as long as this Rebello engine survives.
> --Pat K
> "Michael R. Clements" wrote:
>
> > Scot Zediker wrote:
> >
> > > Guess they're geared a
> > > lot higher than my car,
> >
> > Which gave me a major epiphany (thank you Scot).
> >
> > This touches on a confusion I've always had about gearing
> > terminology. From an engineer's point of view, the total gear
> > ratio is measured as the rate of rotation of the crankshaft
> > divided by the rate of rotation of the wheel of the car. That
> > means 1st is higher than 2nd, etc.
> >
> > But often times, the colloquial terminology is the opposite. As
> > an engineer, one would say that a Vette (for example) is geared
> > lower than a Miata (for example). However, I've heard people
> > (Scot, for example) say the opposite while meaning the same
> > thing. That means the layman's meaning, and the engineer's
> > meaning, of the same word, may be opposites.
> >
> > So in layman's terms,
> >
> > 1. Is 1st gear higher or lower than 2nd gear?
> >
> > 2. Is 1st gear taller or shorter than 2nd gear?
> >
> > 3. Is 1st gear "bigger" or "smaller" than 2nd gear?
> >
> > P.S.
> >
> > I think I'm finally understanding why people argue about power
> > and torque so much -- they actually agree, but they attach
> > opposite meanings to the same words!
> >
> > --
> > Michael R. Clements
> > mrc01@flash.net
> > We must make clear that communism and the governments it now
> > controls are enemies of every man on Earth who is or wants to be
> > free.
> > -- Barry Goldwater
--
Michael R. Clements
mrc01@flash.net
We must make clear that communism and the governments it now
controls are enemies of every man on Earth who is or wants to be
free.
-- Barry Goldwater
|