What Gear Ratio
Thread Starter
Racer
Joined: Mar 2001
Posts: 327
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From: Southlake, Texas, USA
What Gear Ratio
For a 78? I checked it last night and I think I got 3:70 something. Move the wheel to almost 2:00 position before the driveshaft move 4 turns. Am I currect on this?
Le Mans Master
Joined: Aug 2000
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From: Semper ubi, sub ubi
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Re: What Gear Ratio (SprintCarDriver)
One way to check and be pretty darned close is to put a mark on your driveshaft. Place the mark on the bottom of the shaft. Then with the rearend in the air have someone turn a rear wheel one complete turn. Count how many revolutions the shaft makes. If you have a 3.08 it should turn just past 3 complete turns, 3.30 about 3 and 1/3 turn, 3.55 about 3 and 1/2 turns, 3.70 should give you about 3 and 3/4 turns.
Thread Starter
Racer
Joined: Mar 2001
Posts: 327
Likes: 0
From: Southlake, Texas, USA
Re: What Gear Ratio (Smokehouse69)
Looks like I need to learn how to spell.
Thanks, that is what I did last night, just could not get completely under the car. That is why I move the wheel until I got the mark on the driveshaft to be where I could see it. The driving wheel turned 1 and about 30deg. Subtract that from 4 revolutions on the drive shaft should make it 3:70 and change, Right?
Math and spelling was never my greatest subject! :smash:
Thanks, that is what I did last night, just could not get completely under the car. That is why I move the wheel until I got the mark on the driveshaft to be where I could see it. The driving wheel turned 1 and about 30deg. Subtract that from 4 revolutions on the drive shaft should make it 3:70 and change, Right?
Math and spelling was never my greatest subject! :smash:
Le Mans Master
Joined: Aug 2000
Posts: 9,662
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From: Semper ubi, sub ubi
Cruise-In VI Veteran
Cruise-In VII Veteran
Re: What Gear Ratio (SprintCarDriver)
If your wheel turned 360 + 30 (390 degrees) and the shaft turned 360 degrees, then divide 390 into 360 will give you .923, multiply that times 4 and you get 3.6923 close enough for me.
360 / 360 + 30 = .9233 X 4 = 3.69
360 / 360 + 45 = .8888 X 4 = 3.55
I might be totally wrong, but it makes sense to me! But I never was very good at math, :U unless it had to do with cars! :D
360 / 360 + 30 = .9233 X 4 = 3.69
360 / 360 + 45 = .8888 X 4 = 3.55
I might be totally wrong, but it makes sense to me! But I never was very good at math, :U unless it had to do with cars! :D
Team Owner
Joined: Aug 1999
Posts: 28,704
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From: Fort Mill, SC via NJ
Re: What Gear Ratio (SprintCarDriver)
You could try here
http://www.smokemup.com/utilities/calc/rear_end.cfm
http://www.smokemup.com/utilities/calc/rear_end.cfm
