Re: [AMC-List] Trans for 232 six.

[Tom Jennings <tomj@xxxxxxx>]

On Wed, 6 Dec 2006, Swygert, Francis G MSgt 436 CES/CECM wrote:

> Someone mentioned using this trans, or rather a lock-up version and a
> high gear (2.53 or so) in the rear. I know AMC used a high gear like
> that in Spirits and possibly Concords to get fuel mileage up. But I have
> to tell you, that only works for highway mileage. In town mileage
> suffers with such a high gear. I'd stick with something like a 3.08, no
> higher than a 2.73. The auto does multiply engine torque by about 3:1,
> so that helps get the car moving, but a little more gear surely won't
> hurt. Those 2.53 geared cars are just a bit on the sluggish side taking
> off. Unless you're planning on a lot of highway cruising you'll
> appreciate a little more gear.

I'm with Frank here --

I run 25" tires (205/70-R14's), a 2.73:1 axle, and an early 904
(non-lock up), and a 258 with the later aluminum intake, a 2
bbl Weber, 2.5" exhaust turbo muffler, Duraspark II ignition,
and careful tuning -- quicker than stock but not that much.

The 70 Hornet is a lot lighter than later cars, no side-impact
panels in the doors etc, so it's pretty much a 60's American,
chassis-wise.

2.73:1 is as steep as I'd want to go; it's about the right
compromise overall. It really wants a lower first gear; the
motor pulls hard, but the overall ratio in first is steep (it
was designed as an economy car...). It will just barely smoke
the tires from dead stop.

Yet performance at highway speeds is excellent; 50 - 80 mph,
I'm faster than most things on the road, it pulls like hell
to 90mph!  But that's because 68mph = 2500 rpm, a bit fast for
maximum mileage... I feel like 2000 - 2100 for 65mph would be
better for mileage, but of course then performance would suffer
if I just changed the axle to get that.

AMC knew what it was doing; it picked a pretty good combo for
overall performance and mileage given a big inefficient six
and an inexpensive 3-speed auto trans. What did this car cost
new, $2500?!


The "ideal" combo for me would be a 15% lower total first-gear
overall ratio, yet 2000 rpm at 65mph. A four speed and
axle-juggling would get that (or my T150+OD).

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