Calculating effect of rear end ratio change

Transmission to Rear-end

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edfiero
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Calculating effect of rear end ratio change

Post by edfiero » Sun Nov 08, 2015 9:11 am

Are there any online calculators to estimate the effect on acceleration (1/4 mile time), for a given rear end ratio change (or tire size change)?

For a given car that has some quarter mile time, say 13.0 with a 3.73 rear, I'd like to estimate the time if the rear was changed to a 4.10.

I know there are a multitude of variables there like whether or not the rear end change results in an additional shift before the end of the quarter or not, torque curve of the engine, etc, but I am interested in a 'ballpark' way to compare two similar engines which have different trannies or rear end ratios. I understand the higher rear end ratio numerically will typically result in a faster time, but perhaps lower trap speed, but I don't know to go about estimating HOW MUCH FASTER. Hoping someone has done the heavy lifting and there is an online calculator to play with.

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