skyline differential swap

[s14_sport]

currently I have an RB25 installed in my S14 and I have a J30 rear diff.

I also have a skyline GTS-T rear diff that I'm going to install this weekend.

The J30 is 3.916 final gear ratio and the skyline is 4.363

I don't know anything about these ratios, so what does the bigger gear mean in performance?

[jdmser]

The taller(lower the number) the gear the more top end you get. The shorter(bigger the number) the gear the better acceleration in the lower rpm range.

[s14_sport]

sweeeet! so when i do this swap my car should feel FASTER...

[Carl H]

yessir.it will also mess up your speedometer output unless you change the pinion or get a signal modifier.