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smiths telemetric speedo
lewis - 11/3/11 at 02:16 PM

hi all,right i have got my speedo working(loose sensor bracket) but the speedo seems to be over-reading i went for a drive today and it said i have done 91 miles! but could not have done more than 40. how do i adjust it? i have no instructions also will i need to put in a code? ie. http://www.greengauges.com/help/faq20.asp if so how do i do this? i am running 14" 60 profile wheels and the sensors are on the propshaft.cheers.

lewis - 11/3/11 at 02:26 PM

This is how my gauge is set at the moment



(10 is off)

[Edited on 11/3/11 by lewis]

mcerd1 - 11/3/11 at 03:23 PM

yes you'll need to work out the number of pulses per mile then look up and program in the code thats the closest

there are 2 kinds depending on the age of the gauge:
new gauges
older gauges


we'll need a few other thing to work that out for you

whats the rolling radius of your rear tyres ?
should be listed by the manufacturer - if not wats the width? (14" 60 profile isn't enough on its own)


if its reading off the propshaft - how many teeth/ bolt heads are there (1 complet turns worth)

what ratio is your diff ?

lewis - 11/3/11 at 04:07 PM

Ok some more info 14/60/185 tires the sensor is picking up it's signal from 2magnets glued to the propshaft

rusty nuts - 11/3/11 at 04:50 PM

You still need to know the diff ratio

lewis - 11/3/11 at 04:57 PM

Not 100% but was told it's a 3.62

Bigheppy - 11/3/11 at 06:22 PM

Another way is to drive along the road and see what your indicated speed is and compare it with a sat nav. Adjust the switch or number settings and then repeat the test at the same speed on the sat nav and notice how the adjustment has affected the indicated speed, adjust the settings until the indicated speed reads a few mph over the sat nav indicated speed. Job done. It took a few attempts but its how I set mine

lewis - 11/3/11 at 06:30 PM

But which switches do I move? I take it some are for big adjustments and some are for small?

rusty nuts - 11/3/11 at 06:38 PM

Have a look at the speedometer fitting instructions for how to work out the settings you need not the calibration page

snapper - 11/3/11 at 07:42 PM

Google Caerbont and look for the instructions, it's all on there.

mcerd1 - 11/3/11 at 08:11 PM

quote:
Originally posted by lewis
But which switches do I move? I take it some are for big adjustments and some are for small?

its a binary number you programing in - its related to the number of pulses per mile but not the same as it so don't worry too much about what it means


follow the instructions on this page: link

then look up the setting you need here: link




by my rough working

185/60 R14 = ~1762mm per rev = 0.00109485604 miles per rev
so thats 1 / 0.00109485604 = 913.3620891382213 revs pre mile

if your diff is a 3.62 then that means it turns 3.62 times for evey turn of the wheels
and you have 2 magnets so that twice again

so 913.3620891382213 * 3.62 * 2 = 6612.7

so thats approx. setting 6613 = 0100000010
(were 0 is off and 1 is on, starting at #1 ending at #10)

a 3.92 diff would maek it more like 7166 = 1110100010


if I'm reading it right it looks like its currently set on: 6950 = 1111000010





please don't take that at face value - always best to triple check these things before you get done by a speed scamera

{ps - Have I done that right ?}

[Edited on 11/3/2011 by mcerd1]

lewis - 11/3/11 at 08:24 PM

Thanks alot all especially mcerd1 I'll give the code you have worked out a go,I'll run with satnav to compare so will trust that for now for the cameras!