dsm duster

i have a 94 eg with a H22a obd1 swap, and my speedometer is not accurate. its off by like 3mph under 60 but once i go over 60 it increasing gets worse the faster i go. it gets off by as much as 15mph. so any help with this problem would be much appreciated. also if i were to get an aftermarket speedo would it be accurate or be the same as the stock one?

jbpnoman

Your motor doesn't matter. What transmission do you have? What size tires do you have?

dsm duster

not exactly sure about the tranny but my tires are 205/45/16

jbpnoman

Well, assuming you have an H series transmission attached to your H22A, and not an H2B, switch to a 205/50R16 (stock size on the Prelude) and your speedo should read correctly again. The difference in rolling radius between 205/50R16 and 205/45R16 is 3.5%, which almost exactly matches the numbers you're giving us.

dsm duster

Alright ill have to try that thanks for the help.