Here's a question about gears and horsepower that
I'd like to understand better:
1.My car ran 127 MPH with a 4.11 rear end while
turning 6300 RPM.
2.Now let's assume that I change to an ideal
gear. Let's say I change to a 3.08, (assuming the
motor has the horsepower, but this is now
hypothetical, because it does not have that much
horsepower) but if it did, it should run 170 mph
at the same RPM.
3.If I then change to a gear that's too tall,
let's say a 2.70, and again assuming that it used
it's maximum horsepower to turn the 170, the
force and the resistance remain the same. The
from the 3.08. Will it now just wind out to 5500
and still reach 170 mph? Or, will it wind to
whatever RPM the maximum horspower is produced
and result in whatever speed occurs at that RPM.
I hope I adequately worded my question here. It
turns out the rear end in my car was, in fact, a
4.11:1. I'm getting ready to change it, and I'm
thinking a 3.08:1 should be a good choice,
especially with the cam change. I can still vary
my tire sizes from 25.5" to 28". I ran the 28"
with the 4.11s to reach the 127mph at 6300rpm.
I'll try the 25.5" first with the 3.08, then see
what happens when I jump it up to the 28" tall
tire.
My guess is I will not reach the same RPM with
the higher 3.08 and the shorter 25.5" tires. I'm
hoping maybe 5700 RPM and 140mph. But, this gear
will allow me to add to the motor (spray, maybe)
and then look for a future of 150mph with the
short tires, and whatever the horsepower will
give me, up to 170 with the taller tires.
Waddaya all think?
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* * * * * * * * * * * * * *
* Dick J *
* (In East Texas) *
* # 729 *
* C/GRS C/FRS D/STR *
* * * * * * * * * * * * * *
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