S13 overdrive ratio

[matt0481]

Can someone tell me what the overdrive ratio is for my 5 speed. Also, the output shafts from a J30 diff will work in a NA Z32 diff in my S13, right? Is there any difference between the Z32 and J30 differential, besides ratio?


Thanks,
Matt

[orion::S14]

Z32 diff has the same lengh case as an open diff...no ABS senbsor inthe front like the J30.

And yes, the output shafts will slide right in.

As for the 5th gear ratio, it's .759.

1st .... 2nd .... 3rd .... 4th .... 5th
Gear .. Gear ... Gear .. Gear ... Gear

3.321 , 1.902 , 1.308 , 1.000 , 0.759

- Brian

[matt0481]

Thanks. I was pondering the idea of the J30 diff. to decrease cruising RPMs. I drive a lot of highway miles. probably wouldn't notice enough to warrant it would I?

[orion::S14]

4% reduction in RPM...so at 80mph:

Now, with a 4.083 final drive you run ~3000rpm.

With a J30 diff, it'll run 4% lower, so 2880rpm.

Not really noticeable IMO.

- Brian