Diff ratio question

[bsop]

Ive got a 325is, 1987 and im looking to replace my diff soon, so im curious as to what your opinions would be for an ideal ratio, i have the stick diff in now but shes whining like a whore. Anyway, just looking for general discussion on which ratios you prefer for different situations. I like my current Diff, but im unaware at the moment what its ratio is.

Anyway, all input is appreciated.

[dashboardmonkey]

Ratio should be 3.73-1

IMO you should stick with that, good for dd

[jlevie]

The ideal ratio depends on what you want out of the car. The 3.73LSD is a good compromise between acceleration, top end, and fuel economy. Going up (say to a 4.10) will improve acceleration at the expense of top end and fuel economy. Going down will improve top end and fuel economy at the expense of acceleration.