I recently read an article of yours on the
A833 transmission (posted online). I have
a 1969 Barracuda and was getting ready
to change the rear end gears, they are
too high for my liking. I want to put 4.10s
or maybe 4.30s (away from the 3.23 it
has now). Everything is rebuilt on the
car as it was a complete restoration, the
gears are the last thing and the reason
I’ve kept them on all this time (from May)
is because I wanted to enjoy some highway
driving while getting to know the car
as well but I miss and lack that “off the
line” feeling.
What I wanted to know
is if there was a way to
deduce if I have 4.10 gears
on the back, what does
it feel like when the car is
in first and second….3rd
& 4th. I.E 4.10 in first will
be like having 4.56 or 4.88
and by the time I get to
fourth it will be a 1 to 1
ratio…. Meaning when I’m
in 4th gear the rear end
will have the ration of 4 to
1 etc…
If you understood my
blabbering and have a
formula for said dilemma
of mine, I would be truly
grateful.
It is simple arithmetic. Let’s say that,
with the current 3.23 gearset and current
tire size, the engine is revving
3,000 RPM at 30 MPH in second gear.
If you swap to 4.30:1 gears, the engine
will rev 430/323rds higher. 430 divided
by 323 is 1.33. 1.33 X 3,000 = 3,990
RPM at that same 30 MPH. The same
math will hold true at any road and
transmission speed.
You can flip this around and calculate
the “old” and “new” speeds at any given
RPM.
To me, this swap will absolutely suck.
The only “have your cake and eat it too”
solution is an overdrive trans.