bmwe21.net forums

Hi,

I plan on doing the e36 168mm lsd conversion on my E21 and since most E21 LSDs are rare, expensive, weak and sometimes really worn I thought this would be a better option. My stock diff on my 320/6 is a 3.91 unit as far as I know, the unit I plan on getting is a 3.45 ratio so I was wondering how this would affect my speedo, as I'm sure it would seeing as it's gearbox driven, and would I be able to recalibrate the original speedo? These things are not explained in the conversion thread on here.

Many Thanks.

323i comes with 3.45 as standard, so 220 kph speedo will work

Since the speedo drive is located in the gearbox, any changes behind the box so including the diff or final drive need to be compensated.

320/6 stock diff has a 3.64 ratio and a speedo with a 0.808 correction factor. When you move to a 3.45 from a 323i, it would be best to compensate using a 323i speedo with 0.762 correction factor.

More info in the Speedo Correction Factor Topic in the Our Top Tech Topics section.