quick question -- taller gearing = more acceleration?

[jdm_master_X]

i searched and found the gear ratios of the j30 LSD and the CA18/RB20 LSD. correct me if im wrong, but for the J30 LSD its 3.96 Final Drive and the CA18 AND HCR32 LSDs are 4.4 Final Drive.

now what i understood was taller gearing gave you more acceleration (hence the reason why 1st gear is taller than 2nd thats taller than 3rd, etc.). but from what people say here its the complete opposite, giving you low revs but lots of open end in the higher RPM.

so i would like to know what diff would give more acceleration.

and does anybody have that link to courtesy nissan, where it has a listing of the speedometer gears that correspond to the differentials? i want my speedo/odometer to be as accurate as possible. thank you!

[LayNLow240]

the bigger the number the more acceleration it will have, but less top end that gear is capable of. so 4.4 will give the most acceleration. gear ratios are the same. first gear with the ka trans is 3.321, second is 1.902, third is 1.308, fourth is 1.000 and fifth is .0759. as you can see the ratios get smaller the higher the gear. same thing with rear ends.

[jdm_master_X]

well in that case, are the final drive ratios that i put up above correct?

[koukicody]

for the j30 that sounds right. I think ca/r32 is 4.36 thoughSmaller the final drive number = more top end "freeway gears"Larger the final drive number = quicker acceleration "drag gears"

What motor are you going with? ka, ca, sr, rb?let us know so we can help you to your decision

[jdm_master_X]

im just runnin an SR thats all. its nothing all fast or whatever, but ive always favored acceleration over top speed, and an SR seems to be a good choice because its just so balanced.

[KFL]

http://www.courtesyparts.com/nms/s14/s14_2.htmlLike stated just remember Shorter gearing will throw speedo off a bit IIRC and you lose top end and less gas mileageLonger gearing speedo, gain top end, loose bottom but unoticeble due to (bigger)turbo, gain tad gas mileage4.364 will give you faster accel about xxxrpms each gear

[koukicody]

Go with the stock 4.08 final drive. That will be the best all around. You dont want too high of a final drive with a turbo motor becuase you'll "run out of gear" and have to shift before you get into the boost. Where as a n/a doesnt have to wait for a power adder , so a higher final drive would be more beneficial.

[nightkid86]

The KA transmission is geared really wierd. Going on the interstate in top gear I'm running at 4,000RPM - what a waste of gas. Maybe I'll put in the j30 for a little easier highway cruising.

[koukicody]

At what speed? I had a J30 in my kouki and @60mph i was a lil above 3k rpm. 80mph was about 4k rpm which is kinda burning gas for the ka24de. So there's not too much help with the j30 = /

[jdm_master_X]

http://www.courtesyparts.com/nms/s14/s14_2.htmlLike stated just remember Shorter gearing will throw speedo off a bit IIRC and you lose top end and less gas mileageLonger gearing speedo, gain top end, loose bottom but unoticeble due to (bigger)turbo, gain tad gas mileage4.364 will give you faster accel about xxxrpms each gear

the link i was referring to was the list of speedos for certain r200v diffs.