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  #1  
Old 09-14-2019, 06:01 PM
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Default gear ratios...

thought this is a bit useful
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File Type: jpg gear ratio.jpg (120.0 KB, 56 views)
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Old 11-25-2019, 05:15 PM
70Newport 70Newport is offline
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I am very curious about this chart but a little confused.

My big old Chrysler weighs in at 4100 lbs and had a 383 with a 3.38" stroke. I have 3.23 gears in the rear end so 3.23x 3.38 is 7.91. If I look at a 3.38" stroke and a 4,000 LB car it says I should be 11.75 is my gearing really that far off?
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Old 11-25-2019, 07:43 PM
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Look again. The chart says multiply your axle ratio by transmission first gear ratio. Your torqueflite has a 2.54 first gear, so 3.23 x 2.54 = 8.20

The chart, I'm sure, provides the "ultimate" gear ratio for acceleration from a standing start and doesn't mention tire size, which is a factor among many others...

This is useless information for your fat Chrysler... it's built for smooth, luxurious comfort, not neck-snapping stoplight launches.

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Old 12-05-2019, 01:43 AM
70Newport 70Newport is offline
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Quote:
Originally Posted by Dr Crankenstein View Post
Look again. The chart says multiply your axle ratio by transmission first gear ratio. Your torqueflite has a 2.54 first gear, so 3.23 x 2.54 = 8.20

The chart, I'm sure, provides the "ultimate" gear ratio for acceleration from a standing start and doesn't mention tire size, which is a factor among many others...

This is useless information for your fat Chrysler... it's built for smooth, luxurious comfort, not neck-snapping stoplight launches.

.
My “fat Chrysler” is far from what your thinking of so this info would actually be useful as a point of reference. Thanks for pointing out my mistake though.
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Old 12-05-2019, 08:26 AM
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As Dr Crank said, I think this isn't as useful as it appears. Without factoring in tire size and other factors (like cam and engine specs to start), this doesn't seem to result in anything helpful, in my view.
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Old 12-05-2019, 08:46 AM
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Here's a really good calculator for finding out the desired rpm and tire size.
https://www.reillymotorsports.com/sp...alculator.html
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Old 12-05-2019, 09:47 PM
70Newport 70Newport is offline
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Quote:
Originally Posted by Old Iron View Post
Here's a really good calculator for finding out the desired rpm and tire size.
https://www.reillymotorsports.com/sp...alculator.html
Thanks guys, I always appreciate new tools and opinions. I don’t think there is ever one “right “ way for any build and I for sure don’t think I know everything I could!
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  #8  
Old 12-06-2019, 12:38 AM
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Quote:
Originally Posted by 70Newport View Post
My “fat Chrysler” is far from what your thinking of so this info would actually be useful as a point of reference. Thanks for pointing out my mistake though.
I didn't mean to offend... far from it... everybody here is trying to help, myself included. Please tell us what you're trying to achieve...

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Last edited by Dr Crankenstein; 12-06-2019 at 01:03 AM.
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  #9  
Old 12-06-2019, 10:05 AM
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Rear end gear seems a little high for "drag" racing.
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