Hi Eddie,
The difference between 4.22 and 3.9 is a 7% reduction. The 5th gear reduction
on
a 80 to 82 210 transmission is .821 to 1. About 18% reduction.
You're right in your assumption, you have better cruising RPM's with a 3.9,
(read
that as lower RPM's) with a slight loss in performance. Everything is a
compromise, some just like the 4.22, others like the 3.9 with a 5th gear.
Paul A
Eddie Sheffield wrote:
> On Saturday 28 July 2001 11:10 pm, Frank Clarici wrote:
> > derf wrote:
> > > I think I
> > > remember someone mentioning that the MGB(120 MPH) speedo guts with the
> > > stock Spridget(100 MPH) face would work pretty well with the 5-speed
> > > kit.
> >
> > Yes, the MGB speedo with Spridget 100 mph face works perfect with a 5
> > speed/4.22 diff.
>
> I've notice in a few threads before that the 4.22 diff is preferred with the
> 5 speed. I'm just wondering why. For example, I currently (or should) have
> the 3.9 diff. If I put in a 5 speed, what is the advantage of changing to the
> 4.22 rear? It seems like I would be loosing some of the advantage of having
> the fifth gear. Won't the final ratio of the 5 speed + 4.22 be pretty close
> to the final ratio of the 4 speed + 3.9? I'm thinking mostly in terms of
> highway cruising, not low end acceleration/torque. More interesting in
> comfortable cruising than racing. :-)
>
> Eddie
> 1971 Midget
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