ok, im gonna sound thick here but i have too,,,, i understand that 5th gear is a overdrive rather than underdrive well thats what i think anyway

Please can you tell me which of these are taller with respect to 5th gear and for a higher top speed ?

im totally lost but im sure i understood this,, maybe its cause im ill that im being thick,,, anyway

0.972
0.738
0.825

remember these are 5th gear.. so not sure if im looking for a higher or a lower number when it comes to 5th

im looking to rebuild a gearbox to gave the best options for me,,, and so the main thing is highspeed driving as i seem to do alot of that in the shed and hope to improve it and make it perfect

 

so you want a longer 5th gear for motorways then?

 

Just so's you know what the terminology means, in an "underdrive" gear ratio, the output shaft ends up turning slower than the input. An "overdrive" gear ratio results in the output turning faster than its input. That's all it really means - the term is often misused.

Gear ratios are ultimately just simple maths. For example, an input gear with
33 teeth driving an output gear with 33 teeth will result in the input and output shafts turning at exactly the same speed. This ratio is usually written as 1:1, or just 1.000

Similarly, a 22 tooth input gear, driving an output with 44 teeth, will, as you can probably guess, result in one turn of the input shaft producing half a turn of the output shaft. This ratio is normally written as 2:1, or just 2.000, as it's a reduction ratio of 2:1 - you divide the number of teeth on the output gear by the number of teeth on the input.

On the other hand, a 33 tooth input gear driving a 22 tooth output will result in multiplication rather than reduction of the output shaft speed - overdrive. Here, every turn of the input shaft will result in 1.5 turns of the output. So, when you divide the output by the input you get a ratio of 0.666:1 (or just 0.666).

In other words, when you see a gear ratio expressed, any number greater than 1 is an "underdrive". Anything smaller than 1 is an "overdrive". The the smaller the number, the taller the gear, and the larger the number, the shorter the gear.

0.738 is the tallest of those three options - hopefully you now understand why.

 

thats how i was thinking it but i couldnt think why but im spaced out on flu meds at the min,,, and its affecting my thought more than i belived

i know the smaller number of the diff means taller geared too ( not technical just when looking on a impreza)

im just trying to match my driving style a bit more and was hoping for a taller 5th gear,,, aint gonna happen though as i have it already DOH !

 

actually reading that,,,, i actually understand all of that reading it back slowly and you just simplified how i can discover gear ratios too,,,,, you are as they say "the man"