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I bought a DANA 60 w/4.30 gears last year how much rpm difference at the stripe ....I hear about 300rpm ...what do you guys think?
Specs 440 eagle rods
275 60 15 Drag Rad.
8"ATI CONVERT

WITH 4.10 I was going thru @ 6600 6700

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Your correct the difference will be about 300 RPM, mike

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dont mean to Hijack...what about from 4.56 to 4.10?

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I went from 4.30 to 4.10 it was about 200 rpm did,t make no diff in the et slip

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Its probably important to Note. That similer rpm changes can be had by different tire diameters.


With 3.91,s and a 27.3" tire and swapping to a 26" tire the mathmatical RPM difference is 306 RPM between the two different tire Diameters.

My car was faster with the taller tire and less RPM. Even though the 26" tire had More gear leverage.

Theres a "Sweet spot" with everything, combined in the "Combo"

And Were All never done, looking for them to all match up, mike

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Going from 4.10 to 4.30 how much RPM?

Really? Need a calculator?
The answer is still the same as it was the last 500 times: new ratio ÷ old ratio. In this case 4.88%, for 6,600 it's 322 RPM.

The are almost no relationships in cars that are anything but a direct comparison just like that (and most people get the others wrong anyway).

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Im missing some of your math,

the 322 RPM is right.

the 4.88% is right

but the new ratio/ by the old = 1.0487804878

Okay, I see the .0487804878 part in the equation,
So if you lose the 1. move the decimal two points I see the 4.878 But thats not the way to get to 4.88%

How does one divide the new ratio from the old without a calc. mike At 1.01 am and Im a head, mike

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I bought a DANA 60 w/4.30 gears last year how much rpm difference at the stripe ....I hear about 300rpm ...what do you guys think?
Specs 440 eagle rods
275 60 15 Drag Rad.
8"ATI CONVERT

WITH 4.10 I was going thru @ 6600 6700

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I see a lot of responces concerning the math, you have to remember that if you make the 1st and 2nd gear changes at the same RPM with both rear gear ratio you will be further down the track with the 4;10 than you where with the 4;30 so the RPM drop(EDIT: at the finish line) will not be as calculated due to the car going into high gear with the 4:10 further down the track. It won't spend as much time in high gear so it won't accelerate as fast as it does in high gear as it did with the 4:30 Don't be surprised to see very little ET and MPH changes with that ratio change Do the change it may go quicker and faster, not much probally, but some

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This is true - the math is simple, but the results are confusing. If the engine turns too fast with the 4.30 the MPH will go down even more, etc.

How do you do it without a calculator?
Uh.... the way you did in school, for the last 2,500 years?

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So does anyone know where to get 4.30 PRO gears for a Dana 60? I can't seem to find any available, and .56's are more than I want.

Sorry for the hijack!

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How do you do it without a calculator?
Uh.... the way you did in school, for the last 2,500 years?

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I have been taught that math occurred in or around 3000 BC, 3000 BC and 2010 equal 5010, not 25000 years ago I'm not a PHD in math so maybe my math is inaccurate As in all things scientific, especially racing, not all theory are accurate or valid until tested and verified

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I went from 4.30 to 4.10 it was about 200 rpm did,t make no diff in the et slip

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