Gear Ratio???
#1
Gear Ratio???
I'm trying to figure out what rear differential is in my '72 without counting the teeth. I run 65 mph @ 3100rpm's on the highway. Anyone want to give me an estimate??? The trans is a TH400.
Thanks in advance,
Craig
Thanks in advance,
Craig
#2
RE: Gear Ratio???
Depends on tire size. I'm guessing you have a 3.55 rearend.
Here's the formula if you don't want to jack up the rearend and count the driveshaft revs per wheel revs.
Rear ratio = (2.98 times tire outer diameter in inches) divided by miles/hour per 1,000 rpm
This should get you close enuf that you can tell what the actual ratio is.
Here's the formula if you don't want to jack up the rearend and count the driveshaft revs per wheel revs.
Rear ratio = (2.98 times tire outer diameter in inches) divided by miles/hour per 1,000 rpm
This should get you close enuf that you can tell what the actual ratio is.
#3
RE: Gear Ratio???
Thanks, I'll look at what size they are tonight. I know that they are bigger than stock tires (Goodyear Eagle GT II's) as my speedo says 10mph faster than I'm actually going. I took a handheld gps with me and 76 on the speedo was 75 on the gps.
#5
RE: Gear Ratio???
ORIGINAL: OldSchool72
Thanks, I'll look at what size they are tonight. I know that they are bigger than stock tires (Goodyear Eagle GT II's) as my speedo says 10mph faster than I'm actually going. I took a handheld gps with me and 76 on the speedo was 75 on the gps.
Thanks, I'll look at what size they are tonight. I know that they are bigger than stock tires (Goodyear Eagle GT II's) as my speedo says 10mph faster than I'm actually going. I took a handheld gps with me and 76 on the speedo was 75 on the gps.
Ooops...Typo in my previous post. It's was actually 65 on the gps and 76 on the speedo. Thanks for your input!
#6
RE: Gear Ratio???
ORIGINAL: 73shark
I've got 255-60X15 Eagle GTs and a 3:55. I get 22 mph per 1,000 rpm in 4th.
I've got 255-60X15 Eagle GTs and a 3:55. I get 22 mph per 1,000 rpm in 4th.
#10