Help with eps speedo
 

Hi guys,

Have been investigating about installation of my eps speedo and looking at the calibration instructions.

I have an electronic speedo sensor (standard ford item) bought from a fellow forum member. I was under the impression that this was called a hall effect sensor? In which case I have to multiply the number of poles on the sensor (which I am taking as how many teeth is on the sensor gear???) by the number of cable drive revolutions per mile. Dont suppose anyone has already done this and can confirm if my thoughts are right and knows how many revs it should be? :)

After a bit of internet searching I have found a post on another forum stating that this sensor gives out 5 pulses for 2 rotations of the output shaft (presumably this makes is just an electronic sensor in which case I just need to know the number of pulses per mile or per kilometer)

Making my brain frazzle this early on a sunday morning!!

Cheers

Russ

The standard cable drive speed is 1000 revs per mile. So, sounds like your sensor should give out 2500 pulses per mile if the tyre size is right.

Excellent, cheers albert, will give that a shot. I am running 195/60/R15 tyres. Nothing is easy is it? :confused:

when i was looking into speedo drive ratios it was a bit unclear what you actualy get
all sierras had diffrent wheel/tyre sizes, diff ratios and there is more than 1 type of cable drive in the back of the gearbox (type9).

i could not find out if all the dials are 1000rev/mile :(

there is more than 1 way to work it all out and im not upto date with the ford speedo pickups but didgitalspeedos one is 6pulce/rev and is reedswitch type.

you have to mesure around the wheel like you would your waist then work out how meny turns a wheel does in one mile then work out the wheel/cable drive ratio and work out how meny cable turns in one mile and how meny pulces your pickup has.

Tyre rolling radius is a bit smaller than the tyre overall radius. So I would pencil a mark on the tyre and on the floor, roll one revolution, mark again and measure. But theoretical calculations should be sufficient:
http://www.miata.net/garage/tirecalc.html

i was having a poke about in the garage yesterday
my prop>cable drive ratio is 3.5:1 and my doner should have had a 3.6 diff so wheel>cable is almost 1:1 if everything is orignal?

Brilliant, cheers. Not got any further on with this yet as got totally confused with everything!